2009년 5월 31일 일요일

How humans control their prehension movements?

자료: http://www.gaitech.net/How%20humans%20control%20their%20prehension%20movements.pdf


By Yue Leng, Research Centre for Learning Science, Southeast University

Abstracts: 
Prehension is traditionally described as consisting of two components that are based
on different visual information. The transport component is directed by the extrinsic
properties of visual information; while the grasp component is guided by the
intrinsic properties of visual information. The visual information transports in the
dorsomedial visual stream through the parieto-occipital cortex to reach the frontal cortex. This
analysis of the prehension is named as the visuo-motor channel hypothesis. However,
an alternative description, called the digit channel hypothesis by some researchers,
which consists of determining suitable positions on the object------ on the basis of its
shape, surface roughness, and so on------ and then moving one’s thumb and fingers
more or less independently to these positions. This new view can make up the
disadvantage of traditional view from kinematics, anatomy and brain mechanism aspects.
Key words: prehension, transport component, grasp component, dorsal visual stream, the
digit channel hypothesis


Introduction

Prehension is an elegant and skilled object-directed behavior, which is defined as reaching out to
grasp an object. In the past 25 years, much research has been carried out on the cognitive theory of reaching-to-grasp; however, how humans administrate prehension movements is still under debate. This review will propose several hypotheses on the prehension movement that have been supported by reasonable evidence.


The visuo-motor channel hypothesis

Relation between anatomy and prehension

Early on, in 1981, Jeannerod [9] suggested that prehension is considered to consist of the control
of two components: the “transport” component or “reach” component, the movement of the hand to an appropriate location for gripping the object by moving the shoulder and elbow by
activation of proximal muscles; the “grasp” component or “manipulation” component, the
opening and closing of the aperture between the fingers as they prepare to grip the target by
activation of distal connection.

Relation between visual information and prehension

In reaching to grasp an object in space, visual information is required to specify both the
extrinsic and intrinsic properties of the object [10]. The term “extrinsic” information refers to
properties such as distance and orientation in environment, whereas the term “intrinsic”
information refers to properties which belong to object itself, such as object’s size, shape, color,
surface curve and possibly weight,. It was proved that the division between extrinsic and intrinsic information is useful for its correspondence with the division between the relatively independent, although temporally coupled, components of a prehension: the transport component and the grasp component [10, 21]. In detail, extrinsic properties are required to transport the hand in the correct orientation, in a particular direction and for a particular distance; however, intrinsic properties are necessary to control the grip aperture and to select the most appropriate grasp points [9]. Consequently, visual information about the properties of the object and its location is essential to program the required movements of the arm and hand [17]. 

Formulation of the visuo-motor channel hypothesis

Jeannerod postulated transport and grasp component are controlled by two independent
visuo-motor channels in parallel without sharing information, a change of object location should
affect only the transport phase, and a change in object size of shape only the manipulation phase.
This hypothesis is known as the visuo-motor channel hypothesis. This “classical approach” has
allowed paramount development in the research in prehension. The main reason for finding this
description so attractive is that the two channels correspond nicely to two distinct anatomical
structures and to two distinct types of visual information.

Based on this classical approach, Hoff and Arbib (1993) established a model controlling the
transport and grasp components on the basis of a minimum-jerk approach which developed by
Flash and Hogan (1985), combined with on-line feedback controllers. They proposed that a
“pre-shape controller” determines the grasp component in conjunction with a “hand-closure
controller”.

Concerning the hand pre-shaping, Supuk, Kodek and Bajd recently developed a new method for
evaluating hand pre-shaping during reaching-to-grasp movement, which makes use of all five
fingers in estimation of prehension. The experiment was performed on six healthy subjects
grasping three different objects at various positions and orientations. They found new parameters for the evaluation of finger preshaping, such as pentagon surface area, angle between the pentagon and hand normal vectors, and the angle between the pentagon and object normal vectors. The proposed pentagon approach is more informative than hand aperture used in previous studies, since it involves all five fingers [6].

Temporal coordination of the two components

The execution of the hand to reach and grasp an object is examined by means of various
prehension indices. The transport component is assessed by the wrist velocity profiles, typical
measurements include peak velocity, time to peak velocity, total time, etc. The grasp component
is measured by the maximum grip aperture and time to maximum grip aperture.

The use of objects of different size, shape, and axis orientation requiring different types of
prehension is a common strategy for the study of grasping. Almost, prehension movements were
recorded using the OPTOTRAK 3D system, which is a non-contact motion measurement system
tracks small infrared (IRED) markers that are attached to a subject or object. The main
outstanding features of this system are true real-time 3D/6D data rates (in excess of 2500
markers/second) as well as high accuracy. Researchers use this system extensively to collect data describing hand/arm movements in three spaces. Here we will present several typical
experiments as followed.

Jeannerod showed that the velocity of the transport component (as measured by wrist velocity)
has a bell-shaped profile. During movement, the grasp component (as measured by grip aperture between the index finger and thumb in a precision grip task) reaches maximum grasp aperture (MGA) approximately two-thirds of the way through the duration of the reaching movement. Wrist velocity and grip aperture are temporally coupled as the hand moves toward the goal object.

Furthermore, Timmann, Stelmach and Bloedel (1996) designated subjects started with a normal
finger posture but were required to briefly open and close their thumb and index finger while
transporting the wrist to grasp the object. The changes in the aperture altered most of the
kinematic landmarks of the wrist. As the result, most kinematic characteristics for the wrist
transport, and the velocity profile of the wrist showed two peaks. The time of occurrence of the
firs peak was poorly correlated with the time of the first maximal finger aperture. In contrast, the second wrist velocity peak was highly correlated with the time to the second maximal finger
aperture. The researchers concluded that, as the reach progressed and the object to be grasped
was approached, the temporal relationship between the wrist and aperture components of the
movement became more temporally related.

Then, Mon-Williams and James (2001) showed a remarkably simple “rule of thumb”, in which
they argue that the duration ratio of the opening and closing phases of grip apertures is
proportional to the ratio of MGA and the size of the goal object. This “rule of thumb” is simple
and plausible, but predicts a time of maximum grip aperture that is much earlier than is typically
observed in empirical studies.

However, none of these previous models can deal adequately with the observed temporal
coupling between the transport component and the grasp component of prehension. One reason
for this is that no one has experimentally examined in detail this type of coupling between the
two components.

Hu et al. (2005) offered a quantitative model of the temporal coupling between grip aperture and wrist velocity which has shed some light on this issue, showed experimentally that the
correlation between grip apertures and object size is a sigmoidal function of movement duration.
When wrist velocity reaches its peak values, the correlation between the grip aperture and the
size of the goal object has reached half of the correlation that is achieved by the end of the
movement.

Binocular and Monocular Vision

There is strong evidence from physiological, neurological and behavioral studies to suggest that
binocular vision is important for the control of prehension in both patients (Dijkerman, Milner &
Carey) and normal participants (Servos, Goodale & Jakobson).

Servos, Goodale and Jakboson (1992) demonstrated that grasp movements made under monocular viewing were less “efficient” than those performed under binocular viewing conditions, achieving lower peak velocities and showing prolonged periods of deceleration during the closing phase of the grasp.

As part of a continuing investigation into the role that monocular cues play in visuo-motor control, Marotta, Kruyer and Goodale (1998) examined whether or not subjects could use retinal motion information, derived from movements of the head, to help program and control transport and grasp movements when binocular vision is denied. In their experiment, subjects reached out in the dark to an illuminated sphere presented at eye-level, under both monocular and binocular viewing conditions with their head either free to move or restricting. The result is that, under the monocular condition, they showed fewer on-line corrections when they were allowed to move
their head; whereas under the binocular condition, no such difference in performance was seen.
These results suggested that under normal viewing conditions the visuo-motor system prefers to use binocular information, but can fall back on retinal motion information when binocular vision is not available.

Furthermore, Watt, Bradshaw (2000) asked the subjects to reach for and pick up objects under
binocular and monocular viewing both in the absence of a visible scene around the target objects
(complete darkness with “self-illuminated” objects and hand) , and under normal (fully
illuminated). Analysis of the kinematic parameters indicated that binocular information may play
an important role in normal grasp formation; by contrast, the transport of the prehension appears less dependent on binocular information.

Nevertheless, if one eye becomes worse than the other, the overall binocular visual performance
reaches the monocular levels, and in some cases the overall binocular performance is lower than
that of the good eye alone. This phenomenon is called binocular inhibition which has been
presented in the clinic experiment. Recently, Pardhan, Gonzalez-Alvarez (2005) presented
evidence of binocular visuo-motor inhibition by various tasks under various experimental
conditions, whereby when the vision of one eye is decreased, and the binocular motor
performance is worse than that of the good eye alone.



Brain mechanisms of visuo-motor channel hypothesis

Many authors have investigated the anatomical substrate of transport and grasp visuo-motor
channels, following the flow of visual information from the occipital pole to the frontal cortex.
Visual information leaves the primary visual cortex following two main pathways:
1. a dorsal one directed to the posterior parietal cortex;
2. a ventral one that reaches the cortex of the inferior temporal lobe

The functional characteristics of posterior parietal neurons, and the existence of direct
connections between posterior parietal and premotor frontal cortices, suggested that the dorsal
visual stream was involved in the visual guidance of prehension.

The dorsal visual stream includes at least tow separate channels, a medial one passing mainly
through the visual areas of the SPL, and a lateral one passing mainly through the visual areas of
the IPL. The dorso-medial visual stream has been supposed to carry out the visuomotor
transformation necessary of guiding transport movements of the arms, while the dorsolateral
visual stream the visuomotor transformations necessary for grasp movements [21, 27]. However, recent physiological and anatomical data suggest that the dorsomedial visual stream is involved in both transport and grasp action. This proposal is based on new data on functional organization and anatomical connections of medial sector of parieto-occipital cortex, the region of the brain visual information passes through on the way to reach the frontal cortex.


The digit channel hypothesis

In recent years, the theory of parallel visuo-motor channel hypothesis has been debated and
criticized by several authors from both the experimental and theoretical points of view (see [3, 15, and 23]).

On one hand, viewed from an informational perspective, recent experiments demonstrated that a change in object size or other intrinsic properties affects the kinematics of the transport phase.
Goodale et al. (1994) found that, when grasping irregular objects, the final grip aperture is
determined by the grasping locations on the object’s surface. Similarly, Paulignan et al.,
Jakobson, Chieffi and Gentilucci also put forward objection in terms of the correspondence
between visual information and two components. Consequently, these observations suggest that
the coordination of transport and grasp may not occur via separate channels but rather that there may be a coupled integration which can alter the kinematic relationship of these two features in a functionally specific manner.

On the other hand, from the aspect of the anatomy, against the classical description, Wing et al.,
Haggard and Lemon et al., argued that neither the correspondence between the transport
component and movements of proximal segments, nor the correspondence between the grasp
component and the activation of distal muscles are unequivocal.

Furthermore, in the visuo-motor channel hypothesis, functional and anatomical data suggested
that reaching movements are controlled by a medial parietofrontal circuit that involves the
superior parietal lobule (SPL) and the dorsal premotor cortex (PMd), while grasping movements
are controlled by a lateral parietofrontal circuit involving the inferior parietal lobule (IPL) and
the ventral premotor cortex (PMv, [11, 31]). Nevertheless, it has been demonstrated that the
pathways linking posterior parietal cortex with PMd and PMv, though largely segregated, also
partially overlap [26]. In addition, it is now clear that both PMd and PMv contain cells encoding
the arm direction of movement [1, 12 and 30], as well as proximal and distal representations of
the arm [4, 5 and 19]. The conclusion is that the medial and lateral parietofrontal circuits can
hardly be considered as two separate visuo-motor channels for transport and grasp. They seem
more likely involved in both processes.

Formulation of the digit channel hypothesis

Based on the above objections, an alternative model suggests that separate visuo-motor channels exist for the finger and the thumb, which was proposed by Smeets and Brenner (1999). This hypothesis is known as the digit channel hypothesis. In the digit channel hypothesis, Smeets and Brenner abandoned grip as a variable within grasping. Instead, they regarded grasp as simply moving the fingers and thumb to position on the surface of an object of interest. Recently, there have been more and more studies to support this new view. OPTOTRAK 3D system is used to measure the prehension movements.

Smeets, Brenner (2001) asked subjects to grasp disks with different diameters at marked
positions with tow digits [21]. The positions were at opposite sides of the disk, at the same
distance from the starting position, so that the orientation of the surface was the same for both
digits. The subjects grasped the disks either with index finger and thumb of the dominant hand,
with the same digits of the non-dominant hand, or bimanually with both index fingers. The
results demonstrated that the well-known relation between object size and grip aperture holds for each digit; that the same relation holds if the object is grasped with hands instead of with the
thumb and finger of one hand.

Cuijpers, Smeets and Brenner (2004) have studied the relation between object shape and
grasping kinematics. They asked subjects to grasp elliptical cylinders with different aspect ratios
at various orientations and distances from the subject [2]. The results show that the perceived
shape of the cylinder is used for selecting appropriate grasping locations before or early in the
movement and that the grip aperture and orientation are gradually attuned to these locations
during the movement.

Although the digit channel hypothesis has some advantages over the visuo-motor channel
hypothesis, it still remains an empirical question as to which hypothesis best captures the nature
of prehension. According to the digit channel hypothesis, both the thumb and the index finger are being transported when carrying out a precision grasp, however, in some special situations, the visuo-motor channel controlling the grasp aperture formation will ensure that the distance
between the digits is sufficient for grasping the object whilst avoiding any obstacles within the
workspace. To retain many of the very attractive features of the digit channel hypothesis within
an alternative account, Mon-Williams, McIntosh (2000) have christened the third-way hypothesis. According to this hypothesis, the system transports either the tip of the thumb or the tip of the index finger with the grip formation being controlled relatively independently. This hypothesis suggests why some evidence points towards transport of the thumb whilst other evidence suggests that it is the index finger that is transported. Nowadays, more evidence to support this new hypothesis is still needed [15].



Summary

We have collected all the reasonable hypotheses of the control of the prehension movement,
changing the perspective from one based on transport and grasp to one based on movements of
the individual digits. We compare the two hypotheses from anatomical, neuropsychological,
cognitive perspectives. We expect more and more experimental research on the human’s
prehension movement that is going to be carried out to verify which hypothesis is more
advisable. 



유인원 [Ape, 사람상과]

자료: http://enc.daum.net/dic100/contents.do?query1=10XXX47547

위키백과 ― 우리 모두의 백과사전.
생물 분류 읽는 법
유인원

생물 분류
계:동물계
문:척삭동물문
강:초유강
목:영장목
아목:진원아목
소목:협비원소목
상과:사람상과(Hominoidea)
그레이, 1825

유인원(類人猿)은 영장류 사람상과에 속하는, 꼬리가 없는 종을 말하며, 이는 사람도 포함한다. 2과 8속 21종으로 나눈다.[1]

바바리원숭이(Barbary Ape)와 같은 일부 다른 영장류는 꼬리가 없다는 의미의 "Ape"라는 이름을 속칭에 포함하고는 있으나 이 종들은 실제로 유인원으로 간주하지는 않는다. 고릴라와 대부분의 인간을 제외하고, 모든 진짜 유인원들은 나무를 오르는 데 매우 능숙하다. 잡식성은 이들을 가장 잘 기술하는 특징인데, 섭취하는 음식으로는 과일과 식물 열매, 그리고 대부분의 경우에 어디서든 손에 넣을 수 있고, 쉽게 소화할수 있는-사냥을 하거나 다른 동물의 먹고 남은 음식물을 먹는-고기와 무척추동물들이다. 본래 이들은 아프리카와 아시아에서 살았으나 인간들은 세계 모든 곳에 흩어져 살고 있다.

유인원 종들의 대부분은 희귀하거나 멸종될 위험에 처해 있다. 몇몇 개체들이 부시미트용으로 사냥되고 있는 위험에도 불구하고, 멸종될 위험에 처해 있는 대부분 종들의 가장 큰 위협은 열대 우림 서식지의 감소이다.

[편집]분류

[편집]분류의 역사

2006년 현재 사람상과는 위에서처럼 2개 과 8개 속으로 나누고 있다.

1758년 카를 폰 린네가 처음 이명법을 제안하면서 영장류를 사람속(Homo), 원숭이속(Simia), 여우원숭이속(Lemur)으로 나누었다. 그러면서 오랑우탄을 원숭이속의 Simia satyrus로 명명했다. 1775년 블루멘바흐는 침팬지를 Simia troglodytes로 명명했다. 1799년 Lacépède이 오랑우탄을 오랑우탄속(Pongo)으로 다시 명명했다.

1960년까지 사람상과는 사람과 그 조상을 포함하는 사람과(Hominidae)와 다른 유인원으로 이루어진 오랑우탄과(Pongidae)의 둘로로 분류했다..[1]


1960년대 분자생물학의 기술을 영장류의 분류에 적용하기 시작했다. Goodman은 1963년 혈청단백질의 면역학 연구를 통해 대형유인원으로 이뤄진 오랑우탄과(Pongidae)와 소형유인원으로 이뤄진 긴팔원숭이과(Hylobatidae)를 분리, 세 과로 나누었다.[2] 세 과 중 어느 과가 공통 조상으로부터 먼저 갈라져나왔는지는 이후 과학자들의 연구 과제가 되었다.


사람상과에서 긴팔원숭이류가 우선 나뉘었다. 그 결과 다른 대형유인원을 사람과 함께 사람과로 합치고 사람과를 사람을 포함하는 사람아과(Homininae)와 대형유인원으로 이뤄진 오랑우탄아과(Ponginae)로 나누었다. 오랑우탄아과에 속하는 세 속의 근연 관계에 대해 과학자들은 다시 주목하였다.


연구 결과 오랑우탄이 별도의 종류임이 밝혀졌다. 그러나 아프리카 유인원(침팬지와 고릴라)이 오랑우탄보다 사람에 더 가깝다는 것도 함께 밝혀졌다. 따라서 아프리카 유인원을 사람아과로 옮기게 되었다. 이 분류는 1974년 M. Goodman이 처음 제안했다.[3]


사람아속의 세 속을 정리하기 위해서 일부 학자들은 사람속을 아프리카 유인원으로 이뤄진 고릴라족(Gorillini)과 사람족(Hominini)으로 나눌 것을 제안했다


하지만 DNA의 비교 연구를 통해 고릴라가 사람아속에서 가장 먼저 독립었다는 납득할만한 증거가 제공되었다. 침팬지를 사람과 함께 사람족으로 분류하게 되었다. 이 분류는 1990년 M. Goodman 등이 처음으로 제안했다.[4]


그후 DNA의 비교 연구를 통해 긴팔원숭이속을 4개 속으로 나누었다.


[편집]참고문헌

  1. ^  G. G. Simpson (1945). The principles of classification and a classification of mammals. Bull. Am. Mus. Nat. Hist. 85: 1–350.
  2. ^  M. Goodman (1963). "Man’s place in the phylogeny of the primates as reflected in serum proteins" S. L. Washburn Classification and human evolution, 204–234, Aldine, Chicago.
  3. ^  M. Goodman (1974). Biochemical Evidence on Hominid Phylogeny. Annual Review of Anthropology 3: 203–228.
  4. ^  M. Goodman, D. A. Tagle, D. H. Fitch, W. Bailey, J. Czelusniak, B. F. Koop, P. Benson, J. L. Slightom (1990). Primate evolution at the DNA level and a classification of hominoids. Journal of Molecular Evolution 30: 260–266.

[편집]주석

  1. ↑   (2005년 11월 16일) Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press.ISBN 0-801-88221-4.
  2.  (1990) Primate evolution at the DNA level and a classification of hominoids. Journal of Molecular Evolution 30: 260–266.DOI:10.1007/BF02099995.

2009년 5월 30일 토요일

uncertainty, and its synoyms

1. The condition of being uncertain; doubt.
2. Something uncertain: the uncertainties of modern life.

***
Synonyms: uncertainty, doubt, dubiety, skepticism, suspicion, mistrust

These nouns refer to the condition of being unsure about someone or something. 
  • Uncertainty, the least forceful, merely denotes a lack of assurance or conviction:
      ... I regarded my decision with growing uncertainty
  • Doubt and dubiety imply a questioning state of mind:
      ... "Doubt is part of all religion" Isaac Bashevis Singer.
      ... On this point there can be no dubiety
  • Skepticism generally suggests an instinctive or habitual tendency to question and demand proof:
      ... "A wise skepticism is the first attribute of a good critic" James Russell Lowell. 
  • Suspicion is doubt as to the innocence, truth, integrity, honesty, or soundness of someone or something:
      .. His furtiveness aroused my suspicions
  • Mistrust denotes lack of trust or confidence, as in a person's motives, arising from suspicion:
      ... The staff viewed the consultant's hasty recommendations with mistrust.

2009년 5월 27일 수요일

Managed care 개념이 헷갈리는 이유

자료: http://blog.naver.com/pez08/100060875345


Managed care 개념이 헷갈리는 이유는 그 종류가 다양해서일것이다. 물론, MCO (managed care organization)들이 사회적으로 도움이 되는지 아닌지에 대한 논쟁도 헷갈릴 수 있지만, 그건 조금 다른 종류의 문제이고. 옛날 자료이긴 하지만 1998년 Health affairs에 실린 자료를 보면, 직장인들의 35%가 PPO, 27%가 HMO, 24%가 POS, 그리고 나머지 14%가 기존의 보험을 들었다고 한다.

HMO (Health Maintenance Organization): HMO 네트워크 내에 있는 병원/의사들에게 받은 치료만 보험 처리가 된다. 전문의를 만나려면 거의 항상 일반의 (primary care physician)의 처방이 필요하다. 병원 utilization에 중점을 두다보니 PMPM (per member per month)로 의사들에게 지급하는 capitation제도 이다. 의사들은 많은 환자를 보고자 하는 incentive를 갖게 된다.

POS (Point of Service Plans): HMO와 달리 네트워크 밖의 병원/의사들에게서 받은 치료도 보험처리해 준다. 단, 본인 부담이 네트워크 안에서 받은 때보다 훨씬 높아진다. 전문의를 만나기 위해서 '대부분' 일반의의 처방이 필요하다.

PPO (Preferred Provider Organization): POS와 비슷한데 network범위가 훨씬 넓다. 네트워크 밖에서는 마찬가지로 혜택이 줄어든다. 보통 일반의의 진단 없이도 전문의를 만날 수 있다. HMO와 달리 Fee-for-service제도이다. 즉, 진료의 난이도와 의사가 써야 하는 시간에 따라 의사에게 지급하는 금액이 달라진다. 의사들은 각 환자들에게 최선을 다하지만 동시에 불필요한 치료를 하게 되는 역효과가 우려된다.

PSO (Provider-Sponsored Organizations): POS와 비슷한데 의사들에 의해 이루어졌다는 것이 다른점이다. 네트워크 밖의 진료에 대한 혜택은 개개 plan마다 조금씩 다르다. 요약하자면, HMO가 가장 strict하고 PPO가 가장 generous하다. 물론 보험 premium은 여기에 반대로 책정되는 일반적이다.

우리나라는 어떤가? 우리나라에도 이런 형태의 사보험이 있는가?

근래에 들어 기존 보험사들에 의해 '건강보험' 상품으로 많이 도입되어 있다. 차이점이라면, 미국의 MCO들은 Provider들에게 돈을 지급하지만, 한국은 환자들에게 한다는 점. 별로 중요해보이지 않을 수도 있지만, 이것이 의미하는 바는 의외로 크다. 미국 MCO들은 출범부터 provider들(의사, 병원 등)에게 돈을 주는 입장을 차지하면서 막강한 영향력을 행사해 왔다. 이를 통해 의료 분야의 효율적인 운영을 요구하고 결과적으로 비용을 낮출 수 있다는 것이 MCO의 존재 근거였다. 물론 소비자들의 선택의 자유를 제약한다는 비난과 여전히 치솟는 보험비용등 많은 문제점들을 노출하고 있기는 하다. 이에 비해 한국 보험회사들은 provider에게 갖는 영향력이 극히 제약되어 있다. 미국 MCO의 논리를 빌리자면, 비용이 줄일 수 있는 여지가 없다는 것이다. 그런 상태에서 보험회사가 돈을 번다는 것은 (사업을 통해 이윤을 남긴다는 것은) 결국 소비자에게 비싼 보험료를 부가한다는 이야기이다. 정부 보험의 coverage가 제약되어 있는 상태에서 추가적인 혜택을 제공하다는 점을 통해 소비자에게 비싼 가격을 책정할 수 있는것이 현실이다. 하지만, 과다한 비용은 분명 빈부의 격차에 따른 의료 혜택의 차별을 발생시킬 것이다. 특히, 정부가 사보험을 핑계로 정부보험의 혜택을 줄여나간다면 이문제가 더욱 커져 나갈 것이다.

2009년 5월 26일 화요일

The Agora Pnyx Paradox

자료: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1020834


George Mickhail
University of Wollongong; Universite D'Orleans (France) - Faculte` Droit Economie et Gestion

2007

U of Wollongong School of Accounting and Finance Working Paper No. 07/15

Abstract:

The avatars of the new capitalism are decreeing how the larger economy should evolve, and follow their efficient reconfigurations of human, technological and physical resources, because it adds up to more freedom. This presented the political space with the opportunity to converge with the economic space. The result was the corporatisation of government that is inherently neo-liberal (or neo-conservative) that often produced analysis-free policies. Coupled with that, was the evolution of the passive consumer-citizen. These three challenges facing our transparent society bring into question the legitimacy of a democratic process, that seems to be driven by cultural forms which celebrate personal change and indifference, but not collective progress. This paper concludes that freedom is not just an individual matter, given the complexity of the issues, such as with surveillance and privacy, so a collective response backed by intellectual analysis can effectively confront the totalising discourse of the powerful, and force its own version of reality on the public agenda.

Keywords: Agora, efficiency, pnyx, transparency, accountability, privacy, surveillance

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An excerpt from The Culture of the New Capitalism

자료: Google Books



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... [knowl]edge model of treating health as a series of transactions with doctors rather than long-term relationships. The reform ignored the dense, everyday experiences of patients and doctors in filling out forms; it supposed well-organized computerized activity of face-to-face diagnosis and treatment. The reformers were impatient with the messy realities of being ill; they instead treated the sick like entrepreneurs.

Impatience with "the twisted timber of humanity" has, of course, a long lineage--so long, indeed, that policy making should have learned from it; policy should grow from the ground up. In fact, the hold of new institutional thinking, in politics and in business, skirts doing so. Edmund Burke, Kant, and other observers of French Revolution watched in horror as the revolutionaries monitored and attacked the realities of everyday life, trying to straighten out the twisted timber; the character of modern reform is instead uninterested; it negelects the ground because daily life seems merely provisinal.

....

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In this provocative book Richard Sennett looks at the ways today’s global, ever-mutable form of capitalism is affecting our lives. He analyzes how changes in work ethic, in our attitudes toward merit and talent, and in public and private institutions have all contributed to what he terms “the specter of uselessness,” and he concludes with suggestions to counter this disturbing new culture.
“Hardly any social thinkers have given serious thought to the drastic changes in corporate culture wrought by downsizing, ‘re-orging,’ and outsourcing. Fortunately, the exception—Richard Sennett—is also one of the most insightful public intellectuals we have. In The Culture of the New Capitalism Sennett addresses the new corporate culture with his usual vast erudition, endlessly supple intellect, and firm moral outlook. The result is brilliant, disturbing, and absolutely necessary reading.”
—Barbara Ehrenreich, author of Bait and Switch: The (Futile) Pursuit of the American Dream

추가 정보
The Culture of the New Capitalism
(공)저: Richard Sennett
출판사: Yale University Press, 2007
214페이지



liminal being

자료: http://en.wikipedia.org/wiki/Liminal_being


From Wikipedia, the free encyclopedia

Chiron, half man, half horse: instructingAchilles

In speculative fiction and, loosely applied, in mythology, a liminal being is a fantasy character that combines two distinct states of simultaneous existence within one physical body. This unique perspective may provide the liminal being with wisdom and the ability to instruct, making them suitable mentors, whilst also making them dangerous and uncanny.

Many beings in fantasy and folklore exist in liminal states impossible in actual beings: