• 한국압력기기공학회 논문집
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• 제13권2호
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• pp.51-59
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• 2017

Steam jets ejected from a rupture zone of high energy pipes may cause damage to adjacent structures. This event could lead to more serious accidents in nuclear power plants. Therefore, to prevent serious accidents, high energy pipes of nuclear power plants are designed according to the ANSI / ANS 58.2 technical standard. However, the US Nuclear Regulatory Commission (USNRC) has recently pointed out non-conservatism in existing high energy pipe fracture evaluation methods, and required the assessment of the unsteady load of the jet caused by a potential feedback mechanism as well as the impact range of steam jet, the jet impact loads and the blast wave effects at the initial breakage stage. The potential feedback mechanism refers to a phenomenon in which a vortex formed by impingement jets amplifies vortex itself and induces jet vibration in a shear layer. In this study, CFD methodology using the LES turbulence model is established and numerical analysis is carried out to evaluate the dynamic behavior of impingement jets and the potential feedback mechanism during jet impingement. Obtained results have been compared with an empirical correlation and experiment.

• Smart Structures and Systems
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• 제6권3호
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• pp.211-223
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• 2010

Accurate sensing of mechanical strains in civil structures is critical for optimizing structure reliability and lifetime. For instance, combined with intelligent control systems, electromechanical sensor output feedback has the potential to be employed for nondestructive damage evaluation. Application of Ionic Polymer Transducers (IPTs) represents a relatively new sensing approach with more than an order of magnitude higher sensitivity than traditional piezoelectric sensors. The primary reason this sensor has not been widely used to date is an inadequate understanding of the physics responsible for IPT sensing. This paper presents models and experiments defending the hypothesis of a streaming potential sensing mechanism.

• The Korean Journal of Physiology and Pharmacology
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• 제2권1호
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• pp.21-30
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• 1998

The effects of GABA and glutamate on the horizontal cells were explored by an intracellular recording method to discern the mechanisms of receptive field formation by chemical coupling in the catfish outer retina. The results suggest that the horizontal cells of the catfish retina might use GABA as their transmitters and that the GABAergic system contributes to the formation of receptive fields of the horizontal cells. GABAC receptors may be involved in a chemical coupling between horizontal cells and concerned with the depolarizing actions by GABA on horizontal cells in the catfish retina. Since the chloride equilibrium potential is more positive than the dark membrane potential in horizontal cells, GABA released from a horizontal cell may depolarize the neighboring horizontal cells. Thus a chemical coupling between horizontal cells may be formed. $GABA_A$ receptors also may be involved in the negative feedback mechanism between photoreceptor and horizontal cell. And glutamate may be involved in connecting positive and negative feedback systems since it potentiated the GABA's actions. Therefore, it is presumed that large receptive fields in the catfish retina are formed not only by electrical coupling but also by chemical coupling between horizontal cells. And information travels laterally by pathways involving both electrical coupling composed of gap junctions and chemical coupling in the retinal network.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.236-243
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• 2000

A number of developments have occurred over recent years that are being used commercially or have the potential to increase the milk yield and consequently the efficiency of dairy cows. Bovine growth hormone is the most widely known of several attempts that have been made to alter the metabolic endocrinology of dairy cows to increase the rate of milk secretion. The factors affecting the milk yield response to growth hormone, growth hormone-releasing factor, thyroxine and placental lactogen as well as to the immuno-neutralization of somatostatin are briefly considered. Secondly, the recent greater understanding of the mechanism by which the milk yield is increased following more frequent milking, which has resulted from the identification and characterization of the feedback inhibitor of lactation (FIL) protein, is reviewed. The identification of this protein provides new avenues of research which may lead to a reduction in the rate of decline in milk yield with advancing lactation or to undiminished milk yields despite a reduction in frequency with which the animals are milked.

• Asia Marketing Journal
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• 제17권1호
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• pp.123-148
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• 2015

Built on regulatory focus theory, this article develops a research model proposing the relationship between management controls (outcome, activity and capability), sales employees' prevention and promotion focus and their behavioral responses (feedback seeking from different sources and relationship investment). The model also suggests that salesperson perceived organizational fit (P-O fit) contributes by influencing the situational self-regulatory mechanism based on regulatory fit theory. To analyze the data, a structural equation model procedure using LISREL 8.5 was employed. To access the potential common method bias, the MV" marker method was applied using a scale theoretically unrelated to at least one scale in the analysis as the MV marker. The results showed that the greater the salesperson's perceived activity control system, the greater the extent of employee prevention focus. The findings also showed that output control and capability control system are positively related to the promotion focus of salespeople. Salespeople's prevention focus relates negatively to the relational investment and positively to organization feedback seeking. The results indicate that salespeople who have promotion focus exhibit the predicted positive influence on their relationship investment. A significant contribution of this research framework is suggesting salesperson regulatory focus as a mediator and its' effects on different types of sales-related behaviors. The author suggests that the motivational orientations of salespeople play key roles in shaping feedback seeking behaviors from different sources; broadly, that employees with a promotion focus will be more sensitive to customers' feedback, and employees with a prevention focus will seek more feedback from the organization. Furthermore, salespeople with a promotion focus will invest more resources to build relationships with customers than salespeople with a prevention focus. This research also explains the moderating role of person-organization fit on the effect of salespeople's regulatory focus and behavioral responses based on regulatory fit theory

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4398-4417
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• 2017

Multi-user Multiple-Input and Multiple-Output (MU-MIMO) has potential for prominently enhancing the capacity of wireless network by simultaneously transmitting to multiple users. User selection is an unavoidable problem which bottlenecks the gain of MU-MIMO to a great extent. Major state-of-the-art works are focusing on improving network throughput by using Channel State Information (CSI), however, the overhead of CSI feedback becomes unacceptable when the number of users is large. Some work does well in balancing tradeoff between complexity and achievable throughput but is lack of consideration of fairness. Current works universally ignore the rational utilizing of time resources, which may lead the improvements of network throughput to a standstill. In this paper, we propose TOUSE, a scalable and fair user selection scheme for MU-MIMO. The core design is dynamic-time-warping-based user selection mechanism for downlink MU-MIMO, which could make full use of concurrent transmitting time. TOUSE also presents a novel data-rate estimation method without any CSI feedback, providing supports for user selections. Simulation result shows that TOUSE significantly outperforms traditional contention-based user selection schemes in both throughput and fairness in an indoor condition.

• 경영정보학연구
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• 제16권1호
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• pp.1-15
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• 2014

소셜미디어(social media) 플랫폼의 인기와 성공은 새로운 비즈니스 모델인 소셜커머스를 창출하게 되었다. 공동구매를 통해 파격적인 가격으로 제품이나 서비스를 제공하는 소셜커머스 시장은 계속적으로 주목할 만한 성장을 하고 있다. 그러나 이러한 성장의 이면에 소비자들의 회의적인 시각도 존재한다. 왜냐하면, 구입한 제품이나 서비스가 실제와는 다르거나, 불합리한 환불정책 등으로 소비자들의 불만이 고조되고 있는 실정이다. 이러한 근원적인 이유는, 소셜커머스 마켓에서 소비자들이 의존할 만한 신뢰형성메커니즘이 제공되지 않고 있기 때문이다. 기존의 e-마켓플레이스에서는 판매자(seller)에 대한 구매자의 평가정보가 일종의 신뢰형성메커니즘을 제공하여 거래의 안정성이 보장되었다. 이러한 점에 착안하여, 본 연구에서는 소셜커머스마켓에서 소비자들에게 물건이나 서비스 정보제공에 있어서 일종의 큐레이터 역할을 하는 MD(merchandiser)의 역할에 주목하고, 신뢰형성메커니즘을 기반으로 MD에 대한 피드백코멘트와 MD의 실적프로파일 정보의 제공이 소비자들에게 어떠한 영향을 주는가를 검증한다. 이를 위해, 124명의 참가자가 실험실(laboratory experiment)연구에 참여하였다. 실험분석결과, MD에 대한 피드백코멘트와 실적프로파일이 소셜커머스 거래에서 신뢰를 높이는 것으로 나타났다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권2호
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• pp.126-136
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• 2004

이 논문은 색상과 위치정보를 이용한 새로운 내용기반 영상검색 알고리즘을 제안한다. 이를 위해서. 질의가 주어졌을 경우, 데이타베이스의 검색공간을 줄일 목적으로 두 가지 종류의 색인 키(Key)를 제시하는데 하나는 영상의 고유한 색상 구성적 특성을 나타내는 주요 색상세트(MCS, Main Colors' Set)이고 다른 하나는 주요 색상마다의 분포 및 위치적 특성을 나타내는 분포 블록기호(DBS, Distribution Block Signature)이다. 이 두 가지 필터(Filter)를 연속적으로 적용하면 영상 데이터베이스로부터 잠재성이 높은 유사 후보 영상만을 걸러내게 된다. 이어서 보다 높은 검색성능을 얻기 위해 새롭게 제안한 쿼드모델 (Quad Modeling)과 유사도 피드백 메커니즘을 이용한다. 이 방법은 색상과 위치정보에 대한 가중치를 역동적으로 조절함으로써 검색성능을 향상시킨다. 실험을 통해서 제안된 알고리즘이 성공적으로 영상검색에 사용될 수 있음을 보인다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2000년도 추계학술대회 및 정기총회
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• pp.95-98
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• 2000

The rapid expansion of the WWW is well known and has huge potential for enabling companies, large and small, to gain new marketplaces globally at low cost, or to be disintermediated by others doing so. A totally new competitive environment opening up new opportunities is upon us. As a result, the electronic commerce is growing quickly and the importance of electronic marketplace is emphasized. From the view of SCM, applying the business-to-business electronic commerce to the relationship between firms is expected to make major changes. This study focuses on the effects of the introduction of web-based purchasing systems on the buyer-supplier relationship. We conduct a case study on the Korean firms The major findings of this study are summarized as follows. First, in introductory phase, some buying firms fail to design the appropriate mechanism for business relationships. It can weaken the cooperation between buyers and suppliers. Second, for critical or customized parts, it is possible to gather the information about potential suppliers and to make business relations using it. Third, using web-based purchasing systems, capable suppliers can take more opportunities to leverage its competence for business relations. So we can expect the positive feedback.

• Molecules and Cells
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• 제43권2호
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• pp.198-202
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• 2020

Comprehensive inhibition of RUNX1, RUNX2, and RUNX3 led to marked cell suppression compared with inhibition of RUNX1 alone, clarifying that the RUNX family members are important for proliferation and maintenance of diverse cancers, and "cluster regulation of RUNX (CROX)" is a very effective strategy to suppress cancer cells. Recent studies reported by us and other groups suggested that wild-type RUNX1 is needed for survival and proliferation of certain types of leukemia, lung cancer, gastric cancer, etc. and for their one of metastatic target sites such as born marrow endothelial niche, suggesting that RUNX1 often functions oncogenic manners in cancer cells. In this review, we describe the significance and paradoxical requirement of RUNX1 tumor suppressor in leukemia and even solid cancers based on recent our findings such as "genetic compensation of RUNX family transcription factors (the compensation mechanism for the total level of RUNX family protein expression)", "RUNX1 inhibition-induced inhibitory effects on leukemia cells and on solid cancers through p53 activation", and "autonomous feedback loop of RUNX1-p53-CBFB in acute myeloid leukemia cells". Taken together, these findings identify a crucial role for the RUNX cluster in the maintenance and progression of cancers and suggest that modulation of the RUNX cluster using the pyrrole-imidazole polyamide gene-switch technology is a potential novel therapeutic approach to control cancers.