• 인지과학
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• 제28권3호
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• pp.173-191
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• 2017

The theories of cultural evolution hold subtly or clearly different stances about definition of culture, pattern of cultural evolution, biases that affect cultural evolution, and relationship between culture and organism. However, the cultural evolution theories have a common problem to solve: As the evolutionary theory of life tries to explain the early steps and the origin of life, the cultural evolution theories also must explain the early steps of the cultural evolution and the role of the human capability that makes cultural evolution possible. Therefore, explanations of the human's unique traits including the cultural ability are related to determine which one is the most plausible among many cultural evolution theories. Theories that tried to explain human uniqueness commonly depict the coevolution of gene (organism) and culture. We will explicitly call the niche construction theory and the dual inheritance theory the 'gene-culture co-evolutionary theory'. In these theories, the most important concept is the 'concept of positive feedback'. In this paper, we distinguish between core positive feedback and marginal positive feedback, according to whether the trait that the concept of positive feedback explains is the trait of human uniqueness. Both types of positive feedback effectively explain the generality of human uniqueness and the diversity of human traits driven by cultural groups. However, this positive feedback requires an end, in contrast to negative feedback which can be continued in order to maintain homeostasis. We argue that the co-evolutionary process in the gene-culture co-evolutionary theories include only the positive feedback, not covering the cultural evolution after the positive feedback. This thesis strives to define the coevolution concept more comprehensively by suggesting the potential relationships between gene and culture after the positive feedback.

• The Journal of Korean Physical Therapy
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• 제31권4호
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• pp.216-221
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• 2019

Purpose: This study examined the effect of visual feedback squat on the core muscle thickness of young adults experiencing back pain. Methods: Thirty adult men and women who experienced back pain were assigned randomly to 15 members of the visual feedback squat group (VSG) and 15 of the normal squat group (NSG) to train three times a week for a total of eight weeks. The core muscle thickness was compared prior to the test for four weeks and eight weeks after the test by dividing it into warm-up exercise, main exercise, and 10 minutes finishing exercise. Before, and four weeks and eight weeks later, the thickness of the core muscle was compared using an ultrasonic imaging system. Repeated measured ANOVA was performed to compare the groups, and a Bonferroni test was performed as a post-hoc test to assess the significance of the timing of the measurements in each group according to the periods. An independent t-test was conducted to test the significance between the groups according to the measurement points. Results: A significant change in the main effects of time and interactions of the time difference in muscle thickness of transvers abdominis were observed between the visual feedback squat and control groups according to the measurement point (p<0.05). No significant difference in the muscle thickness of both muscles was observed between the groups with the exception of the right abdominis (p>0.05). Conclusion: These findings suggest that visual feedback squat exercise is expected to have positive effects on the development of transverse abdominis in core muscles.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.80-87
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• 2018

Consideration is given to the possibility to use changes in buoyancy as a negative reactivity feedback mechanism during temperature transients in heavy liquid metal fast reactors. It is shown that by the proper use of heavy pellets in the fuel elements, fuel rods could be endowed with a passive self-ejection mechanism and then with a negative feedback. A first estimate of the feasibility of the mechanism is calculated by using a simplified geometry and model. If in addition, a neutron poison pellet is introduced at the bottom of the fuel, then when the fuel element is displaced upward by buoyancy force, the reactivity will be reduced not only by disassembly of the core but also by introducing the neutron poison from the bottom. The use of induced buoyancy opens up the possibility of introducing greater amounts of actinides into the core, as well as providing a palliative solution to the problem of positive coolant temperature reactivity coefficients that could be featured by the heavy liquid metal fast reactors.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1707-1710
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• 2014

Background: The objective of this study was to evaluate baseline use and positive rates of staging images (bone scan, CT) in newly diagnosed patients with prostate cancer (PCa) and to improve staging image overuse. Materials and Methods: This retrospective study covered a consecutive series of patients with PCa who underwent stage imaging at our institution between 2006 and 2011. Various clinical and pathological variables (age, PSA, biopsy Gleason score, clinical T stage, positive biopsy core rate) were evaluated by multivariate logistic regression analysis for their ability to predict a positive staging image. All patients were stratified according to the NCCN risk stratification and positive rates were compared in each risk group. Results: 410 patients (100%) underwent a bone scan and 315 patients (76.8%) underwent a CT scan. Some 51 patients (12.4%) had a positive bone scan, clinical T3 and T4 being significant independent predictors. Positive bone scan rates for low-, intermediate-, high-, and very high-risk groups were 0%, 0%, 8.25%, and 56.6%. Some 59 (18.7%) patients had a positive CT scan, with elevated PSA and clinical T3, T4 as significant independent predictors. Low-, intermediate-, high- and very high-risk group rates were 0%, 0%, 13.8% and 80.0%. Conclusions: The incidences of positive staging image in low- and intermediate- risk group were reasonably low. Following feedback on these results, staging in low- and intermediate- risk groups could be omitted.

• Nuclear Engineering and Technology
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• 제43권1호
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• pp.63-74
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• 2011

The 600 MWe, pool-type, sodium-cooled, metallic fuel loaded KALIMER-600 (Korea Advanced LiquId MEtal Reactor, 600 MWe) has been conceptually designed with an emphasis on safety by self-regulating (inherent/intrinsic) negative reactivity feedback in the core. Its inherent safety under the ATWS (Anticipated Transient Without Scram) events was demonstrated in an earlier study. Initiating events of an HCDA (Hypothetical Core Disruptive Accident), however, also need to be analyzed for assessment of the margins in the current design. In this study, a hypothetical triple-fault accident, ULOF (Unprotected Loss Of Flow) with a reduced pump halving time, is investigated as an initiator of a core disruptive accident. A ULOF with insufficient primary pump inertia may cause core sodium boiling due to a power-to-flow mismatch. If the positive sodium reactivity resulting from this boiling is not compensated for by other intrinsic negative reactivity feedbacks, the resulting core power burst would challenge the fuel integrity. The present study focuses on determination of the limit of the pump inertia for assuring inherent reactivity feedback and behavior of the core after sodium boiling as well. Transient analyses are performed with the safety analysis code SSC-K, which now incorporates a new sodium boiling model. The results show that a halving time of more than 6.0 s does not allow sodium boiling even with very conservative assumptions. Boiling takes place for a halving time of 1.8 s, and its behavior can be predicted reasonably by the SSC-K.

• 경영과학
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• 제15권2호
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• pp.239-257
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• 1998

Facing the globalization of world economy, intense market competition, radical change of information technology, firms are obliged to create a new type of organizations characterized by flexibility and adaptability to new and dynamic environments. This paper reviews the theories of complexity in physics briefly and discusses the implications of them on the management of business organizations. It analogizes the core concepts from complexity theories such as cooperative phenomena, self-organization, adaptation, positive feedback, and butterfly effect, and attempts to identify their implications on business management. Particularly, it suggests principles of 'Fractal' management which apply the fractal structure to the business organization.

• 한국콘텐츠학회논문지
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• 제12권2호
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• pp.322-330
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• 2012

본 연구는 Hackman and Oldham의 직무특성이론에 근거하여 대학생을 대상으로 자원봉사활동 직무특성이 활동만족도와 지속의지에 미치는 효과를 분석하였다. 이를 위해 강원도내 6개 대학의 대학생 261명을 대상으로 설문조사를 실시하여 자료를 분석하였다. 연구 결과 대학생의 자원봉사참가율은 평균 71.6%로 나타났으며, 자원봉사활동의 직무특성과 활동만족도, 지속의지는 중간값 보다 낮은 수준으로 나타났다. 자원봉사 활동만족도에 미치는 직무특성의 효과에서는 기술다양성과 과업정체성, 피드백이 유의한 수준에서 영향을 미치는 것으로 나타났고, 지속의지에 대해서는 자율성을 제외한 기술다양성, 과업정체성, 과업중요성, 피드백 모두가 영향을 미치는 것으로 나타났다. 또한 상관분석을 통해 자원봉사 활동만족도가 높으면 지속의지 역시 높아지는 것을 알 수 있다. 따라서 자원봉사관리자는 자원봉사활동의 직무를 직무특성이론에 기초하여 설계(design)함으로써 의미충만감이나 책임감, 결과의식을 높여서 최종적으로는 자원봉사를 통한 동기부여와 성과 향상으로 이어져야 할 것이다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.567-570
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• 2002

The LVDS (Low Voltage Differential Signaling) I/O cells, fully compatible with ANSI TIA/ EIA-644 LVDS standard, are designed using a 0.35${\mu}m$ standard CMOS technology. With a single 3V supply, the core cells operate at 1.34Gbps and power consumption of the output driver and the input receiver is 10. 5mW and 4.2mW, respectively. In the output driver, we employ the DCMFB (Dynamic Common-Mode FeedBack) circuit which can control the DC offset voltage of differential output signals. The SPICE simulation result of the proposed output driver shows that the variation of the DC offset voltage is 15.6% within a permissible range. In the input receiver, the proposed dual input stage with a positive feedback latch covers rail-to-rail input common-mode range and enables a high-speed, low-power operation. 5-channels of the proposed LVDS I/O pair can handle display data up to 8-bit gray scale and UXGA resolution.

• 한국초등과학교육학회지:초등과학교육
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• 제39권2호
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• pp.183-203
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• 2020

The purpose of this study is to investigate the factor for improving elementary and secondary students' positive experiences about science (PES). In-depth interviews with 32 students and 8 teachers from 8 elementary and secondary Science Core schools were conducted to explore the factors for improving the student's PES. The analysis of the results reveal that the eight key factors which had a decisive impact on a student's PES were 'practice-centered exploratory activities', 'student-led class', 'positive and professional feedback', 'construction of knowledge through exploration', 'class considering student's interest and aptitude', 'use of materials related to real life', 'smooth communication and collaboration in group activities', and 'appropriate difficulty in learning content'. There were also five environmental factors that affected these key factors: 'teacher's professionalism for science classes', 'science class environment', 'teacher community in unit schools', 'change in curriculum', and 'scientific activities other than regular classes'. Based on these results, the practical implications for improving the student's PES are suggested.

• 한국전자통신학회논문지
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• 제17권5호
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• pp.913-926
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• 2022

정보 관리가 조직의 핵심 역량으로 인식되면서, 조직들은 정보 관리 및 보호를 위한 정책 및 기술에 대한 자원 투입을 높이고 있다. 특히, 정보보안 활동의 경우, 내부자에 의한 정보 노출 사고가 지속해서 발생함에 따라 조직 내부자 관리에 관심 수준이 높아지고 있다. 본 연구는 조직이 구축한 정보보안 환경 및 지원 구조가 정보보안 준수의도에 미치는 영향을 확인하고자 한다. 본 연구는 조직이 구축한 정보보안 환경 및 지원 구조가 정보보안 준수의도에 미치는 영향을 확인하고자 정보보안 정책 운용 조직 실무자의 설문조사로 수행하였으며, 421개의 표본을 활용하여 구조방정식 모델과 Process 3.1을 활용하여 가설 검증을 하였다. 분석 결과, 정보보안 환경 구축 요인인 진성 리더십과 공정성 분위기, 정보보안 준수 지원 요인인 커뮤니케이션과 피드백이 보안 준수의도에 긍정적인 영향을 주었다. 또한, 진성 리더십, 처벌, 커뮤니케이션, 그리고 피드백이 정보보안 공정성 분위기의 긍정적 영향을 강화하는 것으로 나타났다. 연구 결과는 조직 차원에서 내부자의 보안 행동 강화를 위해 추진해야 할 구조 설계 방향을 전체적으로 제시하였다는 측면에서 조직 정보보안 수준 달성에 기여한다.