• Journal of Advanced Marine Engineering and Technology
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• 제23권1호
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• pp.33-39
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• 1999

In this paper an experimenatal investigation of characteristics of developing ransitional steady flows in a square-sectional $180^{\circ}$ curved duct is presented, The experimental study is carried out to measure axial velocity profiles secondary flow velocity profiles and entrance length by using Laser Dopper Velocimeter(LDV) system. The flow development is found to depend upon Dean number and curvature ratio. Of special interest is the secondary flow generated by centrifugal effects in the plane of the cross-section of the duct. The secondary flows becomes strong from $120^{\circ}$ of bended angle on the duct. The entrance length of transitional steady flow is obtained to $120^{\circ}$ of bended angle of the duct in this experimental conditions.

• 대한기계학회논문집B
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• 제29권11호
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• pp.1189-1198
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• 2005

Direct numerical simulations were performed to investigate the physics of a spatially developing turbulent boundary layer flow subjected to spanwise oscillating electromagnetic forces in the near wall region. A fully implicit fractional step method was employed to simulate the flow. The mean flow properties and the Reynolds stresses were obtained to analyze the near-wall turbulent structure. It is found that skin friction and turbulent kinetic energy can be reduced by the electromagnetic forces. The decrease in production is responsible fur the reduction of turbulent kinetic energy. Instantaneous flow visualization techniques were used to observe the response of streamwise vortices and streak structures to spanwise oscillating forces. The near-wall vortical structures are affected by spanwise oscillating electromagnetic forces. Following the stopping of the electromagnetic force, the flow eventually relaxes back to a two-dimensional equilibrium boundary layer.

• Nuclear Engineering and Technology
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• 제44권6호
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• pp.587-596
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• 2012

The present paper deals with the participation of the University of Pisa in the last International Standard Problem (ISP) focused on system thermal hydraulic, which was led by the Korean Atomic Energy Research Institution (KAERI). The selected test was a Direct Vessel Injection (DVI) line break carried out at the ATLAS facility. University of Pisa participated, together with other eighteen institutions, in both blind and open phase of the analytical exercise pursuing its methodology for developing and qualifying a nodalization. Qualitative and quantitative analysis of the code results have been performed for both ISP-50 phases, the latter adopting the Fast Fourier Transfer Based Method (FFTBM). The experiment has been characterized by three-dimensional behavior in downcomer and core region. Even though an attempt to reproduce these phenomena, by developing a fictitious three-dimensional nodalization has been realized, the obtained results were generally acceptable but not fully satisfactory in replicating 3D behavior.

• 한국건축시공학회지
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• 제19권5호
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• pp.467-475
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• 2019

Delay is one of the most critical issues for construction projects and leads to huge losses in both developing and industrialized countries. The construction sector in Rwanda, a rapidly-developing nation, is no exception. Delays can be mitigated only once we have identify their primary causes, and these may not be the same in each region. This study aims to ascertain the main critical factors responsible for delays in building construction in Rwanda through an intensive literature review and questionnaire survey. A total of 40 delay causative factors were obtained from a literature review and were further classified into nine major categories. The questionnaire survey was distributed to about 80 respondents from clients, contractors, and consultants. From the list of 40 different factors, the top twelve most critical causes were identified as stoppage of work due to cash flow constraints, delay in approving design documents, confidentiality of physical plan, price fluctuations and delay in approving significant change, change orders, delay in performing inspections, Ineffective project planning, inadequate drawing details, unqualified labor, lack of materials on the market and dishonesty.

• Asian Journal of Innovation and Policy
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• 제10권3호
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• pp.404-408
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• 2021

The role of innovation in economic growth and development is extensively recognized today. Innovations allow firms to stay ahead in a competitive environment while also playing a leading role in developing a nation or a region. The capacity to solve critical problems depends on the generation of innovations. Innovations are more important for a developing nation as only through them, they can find appropriate solutions to the issues unique to their context. A robust roadmap that fosters and nurtures innovations in a country has thus become an essential aspect of public policy. In this context, the book The Black Box: Innovation and Public Policy in India by Prof. Rakesh Basant provides an overview of the innovation landscape in India and the challenges it faces in building a robust entrepreneurial and innovation ecosystem in the country. The author provides an extensive analysis of different actors within India's innovation system and recommends policy initiatives to boost and foster innovation.

• 대한의용생체공학회:의공학회지
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• 제13권4호
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• pp.339-352
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• 1992

A numerical simulation of the steady and pulsatile flow across the end-to-side anastomosis was performed In order to understand the role of flow dynamics in the preferential bevel opment of distal anastomotic intimal hyperplasla. The finite element technique was employed to solve two-dimensional unsteady pulsatile flow in that region. The results of the steady flow revealed that low shear stresses occur at the proximally occluded host artery and at the recirculation region in the Inner wall just distal to the toe region of the anastomosis. The nor- mal;zed wall shear rate was increased, as was the recirculation zone size in the host artery of the by-pass graft anastomosis, with increased anastomotic junction angle. In order to min imize the size of the low wall shear region which might result in the intimal hyperplasia in the by-pass graft anastomosis, a smaller anastomotic junction angle is recommended. The pulsatile flow simulation revealed flow that regions of low and ascillating mali shear do exist near the anastomosis as In the steady simulation. The shift of stagnation point depends on the pulsation of the flow. As the flow was accelerated at systole, the stagnation point moved downstream, disappered at early diastole and reappeared during late diastole. Low shear stress was also found along both walls of the occluded proximal artery. However, the diastolic flow behavior is quite different from the steady results. The vortex near the occluded artery moved downstream and inwardly during late systole, and disappeared during diastole. Recirculations proximal to the toe and heel regions were significant during diastole. Shear stress oscillation was found along the opposite wall. The results of the present study revealed that tow shear occurs at the proximally occluded host artery aud the recirculation region in the inner wall Just dlstal to the toe region of the anastomosis. The present study suggested that the regions of fluctuated wall shear stress wit flow separation is correlated with the preferential developing regions of anastomosis neointial fibrous hyperplasia.

• 지역연구
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• 제15권2호
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• pp.21-38
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• 1999

This paper is concerned with analyzing the role of Northeast Asia intercity networks in Northeast Asia in creating regional networks. For the purpose of this paper, we have followed Choe's (1996) definition of Northeast Asia which includes the Russian Fat East, the Northeast region of China, South Korea, North Korea and Japan. The central hypothesis of the paper is that the geopolitical conditions of Northeast Asia compared for example with Southeast Asia, favor bilateral rather than multilateral linkages between nation states. In these circumstances, it is our hypothesis that cities will play an important role in developing a "local image" of regio-nalism and intercity networks. In order to analyze this hypothesis, the paper is divided into three parts. Part A analyzes the emerging urban system of the Northeast Asia region using Choe's concept of the BESETO corridor and updating his data from the late 1980s to the mid 1990s just prior to the financial crisis. This analysis is further supported by the analysis of economic and transportation linkages within the urban system of the region with some discussion of emerging urban nodes. Part B looks at the specific case studies of the region including the Bohai Sea region, the Japan Sea and case studies of Sapporo, the Japan Sea and case studies of Sapporo, Pusan and Shandong province cities. Part C summarizes this preceding analysis and that the development of regionalism and servicing urban nodes is move likely to emerge from a myriad of linkages developed between the region's cities than from a supra-regional role of nation states. This finding has important implications for regional policy formation suggesting that there should be considerate national support for international linkages between cities.en cities.

• 농촌계획
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• 제19권4호
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• pp.213-226
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• 2013

Agricultural tourism is a new kind of industry, which combined agriculture with tourism. It not only has the productive function, but also has the function of improving the quality of ecological environment and supplying people with sightseeing, leisure, vacation. Agricultural tourism is a new kind of industry from the amalgamation of agriculture and tourism: it is based on farm work, characterized by agricultural management, combines agriculture and tourism, and includes the city as a market-place. It satisfies tourist demand with food, lodging, excursions, shopping and entertainment provided by agricultural places and agricultural products. After combining the substance of this study with the primary sources regarding the development of agricultural tourism, I suggest plans for the development of local agricultural tourism on the basis of sustainable tourism theory in case of the Inner Mongolia region. To conduct research, various data such as literature research and surveys are collected and analyzed. According to the result of the research, the Inner Mongolia region has great-wealthy resources for agricultural tourism. However, they have problems as well such as lack of funds, low infrastructure, low business-mind level, low management-mind, the scarcity of mid-supporting organizations for research and education, low awareness, and low service level of the agricultural tourism. In order to solve these problems, have to strengthen publicity, strengthen the county and city communication, educates continuously profession talented person, establish related laws and regulations, increase the integrity of infrastructure. As a developing industry, agricultural tourism is a new field of study which needs more encouraging research. The agricultural tourism of Inner Mongolia Autonomous Region has only just started development resulting in a limited amount of information available for this study. Future planned work entails a continuous in-depth study of Chinese agricultural tourism, considering Inner Mongolia Autonomous Region in particular.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.118-118
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• 2002

Programmed cell death (PCD) is thought as a well-controlled process by which unwanted cells are selectively eliminated. During the last decade many researches have elucidated molecules and their interactions involved in cell death by using largely in vitro induction of cell death or survival signals in a more defined manner, While these critical information and novel findings provide us with clearer understanding of mechanisms underlying cell death, it does by no means explain how PCD occurs and which cells or tissues are affected during normal embryonic development in vivo. In this study, we used zebrafish to examine whether the PCD is occurring selectively or randomly in developing embryos by whole mount in situ TUNEL analysis with specific markers for neural cells. The result revealed that the degree and distribution of TUNEL staining varied considerably throughout gastrulation stage, and there was also a number of TUNEL-negative embryos. Most of TUNEL-positive cells were scattered randomly throughout the blastoderm. During the gastrulation stage about 75 % of the embryos analyzed exhibited more than 5 TUNEL-positive cells. As the dorsal epiblast begins to thicken rather abruptly near the end of gastrulation, TUNEL-positive cells were mainly located along the dorsal side. Although there were some variations in TUNEL staining during segmentation and pharyngeal stages, TUNEL staining continued to be localized to the central nervous system, and was also detected in the sensory organs, trigeminal ganglions, and the primary sensory neurons. High levels of the cell death in developing brain between 20-somite and prim-6 stages are thought to play a role in the morphogenesis and organization of the brain. At prim-16 stage, cell death is considerably reduced in the brain region. Dying cells are mainly localized to the prospective brain region where ectodermal cells are about to initiate neurogenesis. As development progressed, high levels and more reproducible patterns of cell death were observed in the developing nervous system. Intensive TUNEL staining was restricted to the trigeminal ganglions, the primary sensory neurons, and sensory organs, such as olfactory pits and otic vesicles. Thus, PCD patterning in zebrafish embryos occurs randomly at early stages and becomes restricted to certain region of the embryos. The spatio-temporal pattern of PCD during the early embryonic development in zebrafish will provide basic information for further studies to elucidate genes involved in. regulation of PCD largely unknown in vivo during vertebrate embryogenesis.

• 한국멀티미디어학회논문지
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• 제15권12호
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• pp.1449-1455
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• 2012

This paper has developed a system for early diagnosis of senile dementia and mild cognitive impairment (MCI) by developing software to measure the volume of hippocampus. This software consists of two parts; segmentation and analysis. The segmentation part uses ROI and region growing to segment hippocampus region. On the other hand, the analysis part creates a volume rendering of hippocampus. This software is expected contribute in these research fields for dementia diagnosis and its medication planning.