• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.415-422
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• 2014

This paper presents a new approach to solve the multi area unit commitment problem (MAUCP) using an evolutionary programming based particle swarm optimization (EPPSO) method. The objective of this paper is to determine the optimal or near optimal commitment schedule for generating units located in multiple areas that are interconnected via tie lines. The evolutionary programming based particle swarm optimization method is used to solve multi area unit commitment problem, allocated generation for each area and find the operating cost of generation for each hour. Joint operation of generation resources can result in significant operational cost savings. Power transfer between the areas through the tie lines depends upon the operating cost of generation at each hour and tie line transfer limits. Case study of four areas with different load pattern each containing 7 units (NTPS) and 26 units connected via tie lines have been taken for analysis. Numerical results showed comparing the operating cost using evolutionary programming-based particle swarm optimization method with conventional dynamic programming (DP), evolutionary programming (EP), and particle swarm optimization (PSO) method. Experimental results show that the application of this evolutionary programming based particle swarm optimization method has the potential to solve multi area unit commitment problem with lesser computation time.

• 한국항해항만학회지
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• 제46권5호
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• pp.419-426
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• 2022

This study aimed to identify new routes for transporting automobiles from Korea to Mongolia by comparing them with the existing route. At present, a route from the Incheon Port through the Tianjin Port to Zamiin-Uud is commonly used to transport containerized cargo from Korea to Mongolia. This study examined five possible logistics routes from Korea to Mongolia using a time/cost-distance methodology based on real data. Through consecutive discussions with importers and freight forwarders in Mongolia, the potential routes were selected and costs, distance, and lead time were evaluated to provide additional route options for automobile logistics from Korea to Mongolia. The results indicated that each route could be ranked in terms of the total cost while the lead time for all options in the present COVID-19 period is 2 - 4 months, with no difference among the routes. In addition, although the confidence index of all routes was not impressive, route 3 was the most preferred option, followed by route 1. However, the study results cannot provide the answer to the question of "which route is more attractive for transporting automobiles from Korea to Mongolia." This limitation notwithstanding, this study provides real information on the critical factors of distance, cost, and lead time in terms of the selected transportation routes so that importers and exporters can compare the routes in terms of the priority of each factor in uncertain logistics environment.

• 한국식생활문화학회지
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• 제23권5호
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• pp.595-604
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• 2008

This study was conducted to evaluate the menu of a Japanese restaurant in a first class tourism hotel. The calculations used for the menu analysis were conducted using MS Excel 2003. Several previous studies have been conducted to analyze menus. For example, Pavesic used of the weighted contribution margins (WCM) and potential food cost (PFC%) to evaluate menus, while Kasavana & Smith used the mix margin (MM%) and unit contribution margin (CM) to evaluate menus. The menu engineering method focused on the customer's viewpoints, while the Cost/Margin analysis method considered the manager's viewpoints. The menus that need continuous keeping Kasavana & Smith (Star) and Pavesic (Standard) included 'Assorted sashimi with side dishes (big), 'Lunch box special', 'Tempura course', 'Broiled Spanish mackerel and side dishes', 'Shrimp tempura', 'Special sushi', 'Seafood Udong', 'Buckwheat noodles'. The results of this study should increase customer satisfaction and profits at the Japanese Restaurant.

• 접착 및 계면
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• 제25권1호
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• pp.143-151
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• 2024

유기태양전지(Organic photovoltaics, OPV)는 기계적 유연성, 경량, 반투명성, 낮은 제조 비용 등 여러 가지 고유한 특성을 지니고 있어 차세대 신재생 에너지원으로 큰 잠재력을 보여 왔다. 최근 분자구조 및 소자 엔지니어링의 발전으로 19% 이상의 높은 효율을 달성했다. 그러나 이러한 높은 효율을 갖춘 광활성층 물질들은 복잡한 구조로 인해 합성 과정이 복잡하며 제조비용이 높아 상용화에 어려움이 있다. 이 문제를 해결 하기 위해 간단한 구조를 갖는 저비용 광활성층 물질들에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 이러한 낮은 비용의 광활성층 물질 및 이를 합성하기 위한 전략들에 대해 소개한다.

• Architectural research
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• 제26권3호
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• pp.63-72
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• 2024

Due to budgetary constraints, national landmarks symbolic of country's power and cultural stature face significant limitations in their creation. Within the current total project cost management system, there are considerable restrictions on constructing cultural facilities with various forms and designs, and there exists a societal need for a design-first administrative system for public buildings that demand artistry and symbolism. This study explores the potential and limitations of applying exceptions to the total project cost management system through the designation of representative artistic architecture. It discusses directions for the implementation of government-level systems. To this end, a literature review on budget management and national project management was conducted, and an analysis of related policy cases both do-mestically and internationally was performed to select applicable examples and consider their implications for policy utilization within the domestic context. The results discuss the necessity of public art building construction, the issues with construction budgets, and the in-volvement of world-class architects. Analytical implications include the need for realistic budget setting for construction projects, establishing clear promotion criteria, and creating a phased process and expert evaluation panel.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2007년도 제32회 펄프종이기술 국제세미나
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• pp.83-125
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• 2007

Increasing energy costs have caused profitability problems for paper suppliers. Therefore unprofitable lines are being closed down. The actions aiming for improved profits are focused either on cost savings or on increasing the capacity of the remaining machines. The runnability of a paper machine and its total efficiency have a significant effect on energy consumption. Producing one ton of waste paper consumes at least as much energy as producing the same amount of sellable end product. New automation solutions enable significant cost-effective improvements to the total efficiency of a line without large investment projects. The measures focus on minimizing changes, interruptions, interruption recovery times and grade change times. Newest actuators, online quality measurements and wet end analysators create an improvement potential, which can be optimally implemented with the latest machine direction control solutions, based on model predictive control concepts. Equally, drying management is significant to the energy consumption. The newest control strategies optimize the use of various drying actuators for different situations; either by responding to changes as efficiently as possible or by using only the cheapest energy sources in stable situations. An even steam supply, which is vital for paper machines, is achieved with control for the power plant steam network. This makes possible to avoid the delays upon starting the paper machine and assure an even steam supply for the drying section and the actuators. This document describes means which have brought significant energy and raw material savings for paper machines. Metso Automation has provided efficiency improvement packages, which are usually based on optimized control of dry weight and drying in all running conditions. The solutions are based on performance analysis, on which the estimations for improvement potential and the necessary actions are based on. Typically benefits on an annual level have been from hundreds of thousands of euros to over one million euro. For example, variations in dry weight have been decreased more than 50%. The results are presented with a few examples. Additionally, the analysis models, adjustment solutions and the changes in running methods with which the results were achieved, are presented.

• 한국IT서비스학회지
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• 제15권2호
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• pp.185-201
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• 2016

Recently, due to the rapid development of IT (information technologies), a variety of attempts have been made to incorporate IT into other fields such as finance and manufacturing. Among them, a novel concept in the spotlight is FinTech, which is a combined word of finance and technology. FinTech is a line of business demonstrating an innovation development through IT in the financial service industry. One of the most popular types of FinTech is a third-party mobile payment service (MPS), the examples of which can be easily found in South Korea while the actual use of the service is relatively inactive. Therefore, the main purpose of this paper is to empirically investigate influencing factors of intention to use the third-party MPS. Based on individual characteristics and the task-technology fit model, the research model of the study is developed, with switching cost included as a moderating variable. The results of structural equation model testing with 316 potential users of Kakao Pay, one of the most popular business models of the third-party MPS, show that innate innovativeness, task characteristics, and technology characteristics are positively influencing task-technology fit, which in turn significantly affects intention to use the third-party MPS. The negative moderating role of switching cost is also found. These results could help managers develop better strategies to motivate potential users to participate in their services.

• 미생물학회지
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• 제50권1호
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• pp.84-86
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• 2014

길항균을 생물 농약으로 개발하기 위해서는 저렴한 산업용 배지를 이용한 대량 생산 체계를 확립하는 것이 중요하다. 본 연구에서는 풋마름병 방제 효과가 뛰어난 Bacillus amyloliquefaciens SKU-78 균주의 배양조건을 확립하였다. 저가의 산업용 기질로는 콩가루와 옥수수 전분 배지가 균 생장에 가장 효과적이었고, 최초 pH 5.5, 배양 온도 $30^{\circ}C$, 교반속도 150-250 rpm의 조건으로 30 L fermenter를 이용한 배양에서 20 시간째에 최대 생균수($1.2{\times}10^{11}$ CFU/ml)에 도달하였다. 저가의 산업용 배지로 배양한 배양액을 관주 처리하였을 때 65%의 발병 억제 효과를 나타냄으로써 SKU-78 균주의 산업용 배지를 이용한 대량배양의 기초가 마련되었다.

• 한국재료학회지
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• 제28권7호
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• pp.381-390
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• 2018

Shape memory alloys(SMAs) have revolutionized the material engineering sciences as they exhibit exclusive features i.e. shape memory effect(SME) and super-elasticity. SMAs are those alloys that when deform return to their predeformed shape upon heating, they also restore their original shape by removing the load. Research on properties of newly advent of several types of ferrous based shape memory alloys(Fe-SMAs), shows that they have immense potential to be the counterpart of Nitinol(NiTi-SMA). These Fe-SMAs have been used and found to be effective because of their low cost, high cold workability, good weldability & excellent characteristics comparing with Nitinol(high processing cost and low cold workability) SMAs. Some of the Fe-SMAs show super-elasticity. Fe-SMAs, especially Fe-Mn-Si alloys have an immense potential for civil engineering structures because of its unique properties e.g. two-way shape memory effect, super elasticity and shape memory effect as well as due to its low cost, high elastic stiffness and wide transformation hysteresis comparative to Nitinol. Further research is being conducted on SMAs to improve and impinge better attributes by improving the material compositions, quantifying the SMA phase transition temperature etc. In this research pre-existing Fe-SMAs are categorised and collected in a tabulated form. An analysis is performed that which category is mostly available. Last 50 years data of Fe-SMA publications and US Patents is collected to show its importance in terms of increasing research on such type of alloys to invent different compositions and applications. This data is analysed as per different year groups during last 50 years and it was analysed as per whether the keywords exist in title of an article or anywhere in the article. It was found that different keywords related to Fe-SMAs/categories of Fe-SMAs, almost don't exist in the title of articles. However, these keywords related to Fe-SMAs/categories of Fe-SMAs, exist inside the article but still there are not too many publications related to Fe-SMAs/categories of Fe-SMAs.

• 한국기후변화학회지
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• 제8권3호
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• pp.213-220
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• 2017

The purpose of this study is to analyze effects of Greenhouse Gas (GHG) emission reduction in district energy business mainly based on Combined Heat and Power (CHP) plants. Firstly this paper compares the actual carbon intensity of power production between conventional power plants and district energy plants. To allocate the GHG from CHP plants, two of different methods which were Alternative Generation Method and Power Bonus Method, have been investigated. The carbon intensity of power production in district energy plants ($0.43tonCO_2e/MWh$) was relatively lower than conventional gas-fired power plants ($0.52tonCO_2e/MWh$). Secondly we assessed the cost effectiveness of reduction by district energy sector compared to the other means using TIMES model method. We find that GHG marginal abatement cost of 'expand CHP' scenario (-$134/ton$CO_2$) is even below than renewable energy scenario such as photovoltaic power generation ($87/ton$CO_2$). Finally the GHG emission reduction potential was reviewed on the projected GHG emission emitted when the same amount of energy produced in combination of conventional power plants and individual boilers as substitution of district energy. It showed there were 10.1~41.8% of GHG emission reduction potential in district energy compared to the combination of conventional power plants and individual boilers.