• Journal of Electrochemical Science and Technology
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• 제12권2호
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• pp.279-284
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• 2021

The high theoretical specific capacity of lithium-sulfur (Li-S) batteries makes them a more promising energy storage system than conventional lithium-ion batteries (LIBs). However, the slow kinetics of the electrochemical conversion reaction seriously hinders the utilization of Li-S as an active battery material and has prevented the successful application of Li-S cells. Therefore, exploration of alternatives that can overcome the sluggish electrochemical reaction is necessary to increase the performance of Li-S batteries. In this work, an ionic liquid (IL) is proposed as a functional additive to promote the electrochemical reactivity of the Li-S cell. The sluggish electrochemical reaction is mainly caused by precipitation of low-order polysulfide (l-PS) onto the positive electrode, so the IL is adopted as a solubilizer to remove the precipitated l-PS from the positive electrode to promote additional electron transfer reactions. The ILs effectively dissolve l-PS and greatly improve the electrochemical performance by allowing greater utilization of l-PS, which results in a higher initial specific capacity, together with a moderate retention rate. The results presented here confirmed that the use of an IL as an additive is quite effective at enhancing the overall performance of the Li-S cell and this understanding will enable the construction of highly efficient Li-S batteries.

• Oncology Reports
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• 제43권2호
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• pp.711-717
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• 2020

The aim of the present study was to investigate the metabolic and anticancer effects of troglitazone (TGZ) with a focus on the potential role of mitochondrial pyruvate utilization. 2-Deoxyglucose (2-DG) was more cytotoxic in CT26 cancer cells compared with T47D cells, despite a smaller suppression of glucose uptake. On the other hand, TGZ caused a more prominent shift to glycolytic metabolism and was more cytotoxic in T47D cells. Both effects of TGZ on T47D cells were dose-dependently reversed by addition of methyl pyruvate (mPyr), indicating suppression of mitochondrial pyruvate availability. Furthermore, UK5099, a specific mitochondrial pyruvate carrier inhibitor, closely simulated the metabolic and antitumor effects of TGZ and their reversal by mPyr. This was accompanied by a substantial reduction of activated p70S6K. In CT26 cells, UK5099 did not reduce activated p70S6K and only modestly decreased cell proliferation. In these cells, combining glutamine restriction with UK5099 further increased glucose uptake and completely suppressed cell proliferation. Thus, TGZ-mediated inhibition of mitochondrial pyruvate utilization is an effective treatment for cancer cells that are more dependent on mitochondrial glucose metabolism. By contrast, cancer cells that are more glycolysis-dependent may require suppression of glutamine utilization in addition to blocking mitochondrial pyruvate availability for a full antitumor effect.

• Journal of Korea Trade
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• 제25권8호
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• pp.1-24
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• 2021

Purpose - This study categorizes factors that influence the utilization of preferential tariffs based on the characteristics of rules of origin (RoO) and identifies and analyzes the influence of these characteristics on the utilization of preferential tariffs and the trade performance of companies. Design/methodology - In this study, we categorized factors that have an influence on the utilization of preferential tariffs based on the characteristics of RoO and investigated and tested the influence of these characteristics on the utilization of preferential tariffs and the trade performance of companies. For empirical analysis, we categorized the characteristics of RoO into restrictiveness, complexity, and uncertainty. We then developed a research model and formulated hypotheses based on previous studies, and tested the hypotheses using statistical software-(SPSS 25.0 and AMOS 18.0.) Findings - Previous studies suggested that each characteristic of RoO is determined by unique features of a Regional Trade Agreement (RTA). This study conducted an empirical analysis on the influence of the characteristics of RoO on the utilization of preferential tariffs and trade performance. The results confirmed that, overall, the characteristics of preferential rules of origin (PRoO) are related to and influence Korean companies' utilization of preferential tariffs and trade performance. As for the degree of the influence, the characteristics were in the order of uncertainty> restrictiveness> complexity. Nevertheless, complexity turned out not to have an influence large enough to change a company's decision on the utilization of preferential tariffs. Based on these results, this study identified unique features of PRoO and related problems for Korean companies that want to utilize preferential tariffs and suggested countermeasures for their effective utilization of preferential tariffs in the future. Originality/value - Companies that want to use preferential tariffs in international trade have to satisfy PRoO. The issue of origin can be regarded as an essential part of an RTA and RoO, are a crucial criterion in using preferential tariffs. The rules are requirements to claim benefits of preferential trade agreements and are the primary reasons companies have trouble in utilizing preferential tariffs. In this sense, this study categorized the characteristics of RoO, which are a key part of an RTA, and surveyed working-level professionals in charge of international trade at Korean companies to investigate the relationship between these characteristics and the utilizations of preferential tariffs and trade performance of the companies.

• 에너지공학
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• 제16권2호
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• pp.73-82
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• 2007

세계 에너지 수요는 개발도상국을 중심으로 하여 폭발적으로 증가하고 있는 반면 땅 속에 매장되어 있는 화석연료는 점점 줄어들고 있고 화석연료의 사용으로 발생되는 지구 환경오염도 해결해야 할 중요한 과제이다. 이 시점에서 화석연료의 활용도를 높이고 환경친화적인 연료로의 개발이 매우 필요가 있다. 최근 이러한 문제를 해결할 수 있는 연료로서 제시되고 있는 DME 연료에 대하여 국내?외 기술개발, 보급 및 시장현황을 소개하고자 한다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.79-85
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• 2001

The ocean is vital to life on earth providing needed resources, particularly for mankind Nowadays, space utilization of the ocean is burgeoning research field. In the shallow water, an underwater transportation utility for diver is an effective tool for the ocean space utilization, and a Diver Transport Vehicle(DTV) is one of those utilities. The project which started in summer of 2000 is supported by the Korea research Council of Public Science and Technology. The objective of the project is to develop design techniques for DTV integrating the available technologies of KRISO research divisions. In this, the development of DTV is introduced.

• International Journal of Fluid Machinery and Systems
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• 제6권3호
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• pp.152-159
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• 2013

A two-dimensional Darrieus-type hydroturbine system, installed with a wear for flow streams such as small rivers and waterways, has been developed for hydropower utilization of extra-low head less than 2m. There are several problems such as flow rate change and flowing wastes to be solved for its practical use in natural flow streams. In the present study, at first, a design guideline in the case of overflow or bypass flow is shown by using simple flow model. Next, in order to avoid the unexpected obstacles flowing into the hydroturbine, an installation of waste screening system is examined. It is confirmed that the screen is effective with some amount of bypass flow rate, however the output power is remarkably deteriorated.

• Journal of Information Technology Applications and Management
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• 제21권4호
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• pp.15-33
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• 2014

Recently, the service providers are making various attempts to provide smartphone applications for waiting information in order for customers to perceive waiting time short. This research, therefore, investigates the impact of smartphone use on the waiting experience and provide service organizations with effective measures for managing customers' waiting. As a result of this study, utilization of smartphone during the waiting period shows the positive impact on perceived waiting time, acceptability, and emotional response. Among these, the largest impact appears on the acceptability of waiting that has the largest impact on the perceived service quality. In addition, results reveal that smartphone users shows more positive waiting experience than non-users who read newspapers or magazines, watch TV, or do nothing.

• 한국식품과학회지
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• 제10권4호
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• pp.423-430
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• 1978

Since 1950 there has been a dramatic progress in rationalization of the production of sweet potato and potato starch in Japan. This enabled dextrose industry by enzymatic process to develop rapidly due to the success of enzymatic liquefaction and saccharification. Isomerization of glucose to fructose has been studied, and the immobilization of isomerases prompted its products on industrial scale in 1970. Another advance is the development of effective methods of producing high purity maltose. A malto-hexaose forming amylase was discovered in 1971 and attempts are being made for its pharmaceutical utilization. Saccharification of cellulose by cellulase has been studied. Conversion of starch to other polysaccharides is another example for the numerous Japanese activities.

• 자원환경지질
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• 제33권2호
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• pp.139-146
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• 2000

Development of an effective liner by utilization of the tailings frm the Imcheon mine and polymer has been tried. The tailings piled in the Imcheon mine, whose true specific gravity is about 2.86, are composed mainly of quartz, alkali-feldspar, muscovite and pyrite, and mostly (93.7% in volume) coarser than sand grain size (50${\mu}{\textrm}{m}$). Strength, leaching and permeability tests have been performed on the test specimens of polymer concrete manufactured with various mixing proportions of tailings, unsaturated polyester resins(UPR), calcium carbonates, stone powder sludges and granite soils. Polymer concrete specimens with stone powder sludges or granite soils as fillers and aggregates indicate 2.5 to 3 fold higher flexural and compressive strengths and lower permeabilities than those with calcium carbonates, which shows their usability as a waterproof liner. Also, the polymer concrete liner with stone powder sludge fillers is more advisable in aspects of utilization of waste sludges than that with other fillers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.117-135
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• 2016

Performance enhancement is one of the most important issues in high performance distributed computing systems. In such computing systems, online users submit their jobs anytime and anywhere to a set of dynamic resources. Jobs arrival and processes execution times are stochastic. The performance of a distributed computing system can be improved by using an effective load balancing strategy to redistribute the user tasks among computing resources for efficient utilization. This paper presents a multi-class load balancing strategy that balances different classes of user tasks on multiple heterogeneous computing nodes to minimize the per-class mean response time. For a wide range of system parameters, the performance of the proposed multi-class load balancing strategy is compared with that of the random distribution load balancing, and uniform distribution load balancing strategies using simulation. The results show that, the proposed strategy outperforms the other two studied strategies in terms of average task response time, and average computing nodes utilization.