• Membrane and Water Treatment
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• 제6권2호
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• pp.113-126
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• 2015

Salinity gradient power (SGP) systems have strong potential to generate sustainable clean electricity for 24 hours. Here, we introduce a solid-salt pressure-retarded osmosis (PRO) system using crystal salt powders rather than seawater. Solid salts have advantages such as a small storage volume, controllable solubility, high Gibbs dissolution energy, and a single type of water intake, low pretreatment costs. The power densities with 3 M draw solutions were $11W/m^2$ with exothermic energy and $8.9W/m^2$ without at 35 bar using a HTI FO membrane (water permeability $A=0.375L\;m^{-2}h^{-1}bar^{-1}$). These empirical power densities are ~13% of the theoretical value.

• 시스템엔지니어링학술지
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• 제11권2호
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• pp.41-49
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• 2015

Industrial safety is one of the crucial agenda for Government as well as Manufacturing Industry. To cope with the needs, a great deal of policies and technical implementation have been proposed and implemented. With a great increasing attention on the Industry 4.0 and Smart Factory, industrial safety has received as a crucial agenda by the manufacturing industry in particular. Up until now, almost all of them have been made from the environmental aspects, rather than operator or workers. In this paper, we present our research results how to increase the workers' safety via smart factory technology, such as IoT and CPS. Our approach has been to see the problem from SE perspectives, to draw the real issues from the various stakeholders, and define how to solve the problem based on the emerging technologies. The developed systems can give conceptual framework for the 'smart' industrial safety system by providing solution architecture for how to monitor the location of workers, and moving equipments, and generate solutions how to avoid safety problems between them if detected.

• 복식문화연구
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• 제18권3호
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• pp.488-498
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• 2010

This study was intended to develop a multi-purpose, multi-functional design for safety vest to enhance the safety and user's availability. With a limited scope to LED-applied safety vest, this study contemplates on the problems of safety vest on the market and directions for design development with a view to develop its prototype. This is a significant study because it has been conducted concerning a prototype, a cut above the study method of constructing a basic theory. For study method, theoretic considerations on LED and safety vest are followed by case study for LED-applied safety vest currently on the market to draw out problems. Then, solutions for problems with LED safety vest will be found, while planning for a design direction in consideration of safety, functionality and beauty. Scope of study was limited to cases of LED safety vests currently on sale online and offline, excluding cases of common-form luminosity such as HB luminous vest without LED. Accordingly, results of study will help develop the prototype for LED safety vest with an increase of the wearer's safety, and be used as a basic data for developing high-value-added fashion prodcts to meet his aesthetic sense and functionality. This study has limitations. Restricted scope for LED-applied safety vest should be extended to an outdoor wear in follow-up research for the foundation of higher value added.

• 수산경영론집
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• 제28권1호
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• pp.1-26
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• 1997

The Proposal of this paper is to draw up solution about fishing disputes in Korea coastal waters. Small fishing vessels under 8 metric tons which is regulated by the provincial governors, must operate within provincial boundary on the sea as in fishery policy of Korea. on this, I think that the present situations of fishing disputes have related to the fishing license system. Problem of this kind, Before 1970's, fishing disputes rarely took place, and it, if any, did not bring any social conflicts or disputes. Since 1980's, some of fishing disputes have been reported within fisheries society Recently, The disputes have been increasing to become social conflicts between local people concerned and have evoked an argument on whether the provincial boundary on the sea exists. If such disputes continues to increases or remains unsolved, they will bring a tremendous social cost such as an accelerated decrease in fish resources, degradation of fishing grounds, disorder in fishing, destruction of fisheries culture and so on. The reasons for the growing disputes can be specified as fellows : the degradation of fish resources, the present fishing license system which inherently causes competitions in fish catching, irrational ceiling system of fishing vessels, legal problem on existing boundary between neighbouring two provinces, the functional problem of national or regional fishery coordination committee which has been established to coordinate general fishing disputes. This study has also dealt with Japan's experiences in fishing disputes which has the history of more than a hundred years and its coordinating mechanism. In the discussion section, some possible solutions have been briefly touched fer further study.

• 농촌지도와개발
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• 제22권4호
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• pp.405-421
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• 2015

Agro-fishing villages of agriculture and fishery are suffering deepening gap with urban areas due to depreciation from their products market opening pressure. They are facing problems of decreasing and aging population, poor settlement environment, etc. and losing their vitality for their low productivity and lack of young labor force. These issues of agro-fishing villages of agriculture and fishery are divided in so various items and classes that it is plausible to approach in a way to connect each issue in a small frame of each by selecting sub topics according to each item and each class rather than to solve the issues in a large frame. Chungchungnam-do is approaching the issues through 3 agro innovations(agro fishery, agro fishing villages, agro fishing people) in local government level and Durae enterprises are solving local problems through the self supporting residents' community business by utilizing local resources. This study is to draw clues and solutions to vitalize agro fishery villages through community businesses by detailed reviews and research on cases of Durae enterprises' characteristics and their vitalizations and provide a new alternative plan to agro fishery villages losing their vitality and demolishing their communities.

• Korea-Australia Rheology Journal
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• 제15권2호
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• pp.91-96
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• 2003

The sensitivity of the product to the ongoing sinusoidal disturbances of the process has been investigated in the film casting of viscoelastic polymer fluids using frequency response analysis. As demonstrated for fiber spinning process (Jung et al., 2002; Devereux and Denn, 1994), this frequency response analysis is useful for examining the process sensitivity and the stability of extensional deformation processes including film casting. The results of the present study reveal that the amplification ratios or gains of the process/product variables such as the cross-sectional area at the take-up to disturbances exhibit resonant peaks along the frequency regime as expected for the systems having hyperbolic characteristics with spilt boundary conditions (Friedly, 1972). The effects on the sensitivity results of two important parameters of film casting, i.e., the fluid viscoelasticity and the aspect ratio of the casting equipment have been scrutinized. It turns out that depending on the extension thinning or thickening nature of the fluid, increasing viscoelasticity results in enlargement or reduction of the sensitivity, respectively. As regards the aspect ratio, it has been found that an optimum value exists making the system least sensitive. The present study also confirms that the frequency response method produces results that corroborate well those by other methods like linear stability Analysis and transient solutions response. (Iyengar and Co, 1996; Silagy et al., 1996; Lee and Hyun, 2001).

• 한국멀티미디어학회논문지
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• 제22권4호
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• pp.502-514
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• 2019

Existing user research methods are subject to a variety of research conditions such as the amount and variety of data collected and the expertise of the facilitator of a group research session. In this study, we propose a new user research methodology using an 'Issue-Network' system, which is developed based on the theory and methods of social network analysis. The Issue-Network is designed to define problem spaces from the issues raised by users in a group research session in a form of an interactive network graph. The system helps to break out of ordinary perspectives of looking into problem spaces by enabling an alternative and more creative way to connect issues in the network. In this study, we took a case study of generating the Issue-Network on behalf of the problems raised by users in various driving-related situations. We were able to draw three navigation usage scenarios that cover relatively important problem spaces: safety and being ready for the unexpected, smart navigation and notifications, making use of the spare time. In the future, the Issue-Network system is expected to be used as a tool to identify problems and derive solutions in group research sessions involving a large number of users.

• ETRI Journal
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• 제44권4호
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• pp.641-653
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• 2022

In the process of autonomous vehicle motion planning and to create comfort for vehicle occupants, factors that must be considered are the vehicle's safety features and the road's slipperiness and smoothness. In this paper, we build a mathematical model based on the combination of a genetic algorithm and a neural network to offer lane-change solutions of autonomous vehicles, focusing on human vehicle control skills. Traditional moving planning methods often use vehicle kinematic and dynamic constraints when creating lane-change trajectories for autonomous vehicles. When comparing this generated trajectory with a man-generated moving trajectory, however, there is in fact a significant difference. Therefore, to draw the optimal factors from the actual driver's lane-change operations, the solution in this paper builds the training data set for the moving planning process with lane change operation by humans with optimal elements. The simulation results are performed in a MATLAB simulation environment to demonstrate that the proposed solution operates effectively with optimal points such as operator maneuvers and improved comfort for passengers as well as creating a smooth and slippery lane-change trajectory.

• International journal of advanced smart convergence
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• 제12권1호
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• pp.41-52
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• 2023

The purpose of this study is to review the proposed solutions to the Blockchain trilemma put forward by various research scholars and to draw conclusions by comparing the findings of each study. We found that the models so far developed either compromise scalability, decentralization, or security. The first model compromises decentralization. By partially centralizing the network, transaction processing speed can be improved, but security strength is weakened. Examples of this include Algorand and EOS. Because Algorand randomly selects the node that decides the consensus, the security of Algorand is better than EOS, wherein a designated selector decides. The second model recognizes that scalability causes a delay in speed when transactions are included in a block, reducing the system's efficiency. Compromising scalability makes it possible to increase decentralization. Representative examples include Bitcoin and Ethereum. Bitcoin is more vital than Ethereum in terms of security, but in terms of scalability, Ethereum is superior to Bitcoin. In the third model, information is stored and managed through various procedures at the expense of security. The application case is to weaken security by applying a layer 1 or 2 solution that stores and reroutes information. The expected effect of this study is to provide a new perspective on the trilemma debate and to stimulate interest in continued research into the problem.

• 멤브레인
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• 제33권2호
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• pp.70-76
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• 2023

중수는 경수와 다른 물리화학적 특징으로 다양한 생물화학적 변화를 유도할 수 있다. 기존 분리공정의 단점인 에너지소비량을 줄이고자 전기방사 폴리아마이드 분리막을 이용하여 정삼투공정을 이용하였다. 유도용액으로 NaCl과 인산을 사용하였다. 중수농도를 정량화하기 위해 FT-IR 분광법을 활용하였다. 인산과 수소/중수소의 특별한 상호작용력을 분광학적으로 확인하였으며, 정삼투공정으로 농축이 가능할 수 있다는 것을 관찰하였다.