• Title/Summary/Keyword: Fin systems

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An Experimental Study on the Performance Characteristics with Height of a Fin-Tube Liquid Desiccant Dehumidifier (휜-튜브형 액체건조제 제습기의 높이에 따른 성능특성에 관한 실험적 연구)

  • Lee, Su-Dong;Park, Moon-Soo;Chung, Jin-Eun;Choi, Young-Seok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.5
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    • pp.594-603
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    • 2004
  • Several desiccant cooling systems have been developed in terms of cost and performance. In this study a fin-tube exchanger has been used for liquid desiccant dehumidification system. This dehumidifier has been designed to study the absorption characteristic of the aqueous triethylene glycol(TEG) solution which has the flow range from 20 to 50 LPM. The dehumidifier performance characteristics of working factor variables such as inlet solution flow rate, air flow rate, solution concentration and brine temperature have been analyzed. This dehumidifier has the ability to provide running while saving the latent heat load of total energy. The result of this experiment can provide useful data for hybrid air conditioning system.

An Experimental Study on the Performance Characteristic with Height of a Fin-Tube Liquid Desiccant Dehumidifier (핀-튜브형 액체건조제 제습기의 높이에 따른 성능특성에 관한 실험적 연구)

  • Lee, Su-Dong;Park, Moon-Soo;Chung, Jin-Eun;Lee, Jin-Soo
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.25-30
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    • 2003
  • Several desiccant cooling systems have been developed in terms of cost and performance. In this study a fin-tube exchanger has been used for liquid desiccant dehumidification system. This dehumidifier has been designed to study the absorption characteristic of the aqueous triethylene glycol(TEG) solution which has the flow range from 20 to 50 LPM. The dehumidifier performance characteristic of working factor variables such as inlet solution flow rate, air flow rate, solution concentration, solution temperature, brine temperature, air temperature and inlet air relative humidity has been analyzed. The result of this experiment can provide useful data for hybrid air conditioning system.

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The Frost and Defrost Performances of Fin-and-Tube Exchangers with Different Surface Characteristics (표면특성이 다른 두 핀-관 열교환기의 착상 및 제상 성능)

  • 신종민;최봉준
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.6
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    • pp.525-531
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    • 2002
  • The effects of different surface hydrophilicity on frosting and defrosting characteristic were experimentally investigated. Mass of frost and water hold-up was measured. Results showed that no significant difference in the frost mass was found between the two different surfaces while the water hold-up of heat exchanger court be reduced by the enhancement of surface hydrophilicity. Also, the defrosting efficiency m hydrophilic surface was improved by 76%. It was expected that hydrophilic heat exchanger could provide the improvements in both thermal-hydraulic performances and system reliability during frost/defrost operating in refrigeration systems.

A Study on the Characteristics of Easy Payment Systems for Facilitating Online Sales (온라인 시장 활성화를 위한 간편결제 특성에 관한 연구)

  • Choi, Sujung;Kim, Changsik;Kwahk, Keeyoung;Kim, Heewoong
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.12 no.3
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    • pp.259-271
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    • 2016
  • This study develops an extended model to predict customer satisfaction in easy payment systems based on information systems success model. Our data was collected from easy payment systems users and analyzed using PLS. This study selected four variables as easy payment systems characteristics(convenience, variety, security, speed) along with gender being used as a moderating variable. The results showed that convenience and security are turned out to affect customer satisfaction. Additionally, the test of difference in gender revealed that with respect to gender, moderating effects exist in security and speed. This implies that this study can provide different promotion strategies according to gender. Overall, the proposed model could be used to predict customers' willingness to pay on the easy payment systems.

A Study on Trust Transfer in Traditional Fintech of Smart Banking (핀테크 서비스에서 오프라인에서 온라인으로의 신뢰전이에 관한 연구 - 스마트뱅킹을 중심으로 -)

  • Ai, Di;Kwon, Sun-Dong;Lee, Su-Chul;Ko, Mi-Hyun;Lee, Bo-Hyung
    • Management & Information Systems Review
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    • v.36 no.3
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    • pp.167-184
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    • 2017
  • In this study, we investigated the effect of offline banking trust on smart banking trust. As influencing factors of smart banking trust, this study compared offline banking trust, smart banking's system quality, and information quality. For the empirical study, 186 questionnaire data were collected from smart banking users and the data were analyzed using Smart-PLS 2.0. As results, it was verified that there is trust transfer in FinTech service, by the significant effect of offline banking trust on smart banking trust. And it was proved that the effect of offline banking trust on smart banking trust is lower than that of smart banking itself. The contribution of this study can be seen in both academic and industrial aspects. First, it is the contribution of the academic aspect. Previous studies on banking were focused on either offline banking or smart banking. But this study, focus on the relationship between offline banking and online banking, proved that offline banking trust affects smart banking trust. Next, it is the industrial contribution. This study showed that offline banking characteristics of traditional commercial banks affect the trust of emerging smart banking service. This means that the emerging FinTech companies are not advantageous in the competition of trust building compared to traditional commercial banks. Unlike traditional commercial banks, the emerging FinTech is innovating the convenience of customers by arming them with new technologies such as mobile Internet, social network, cloud technology, and big data. However, these FinTech strengths alone can not guarantee sufficient trust needed for financial transactions, because banking customers do not change a habit or an inertia that they already have during using traditional banks. Therefore, emerging FinTech companies should strive to create destructive value that reflects the connection with various Internet services and the strength of online interaction such as social services, which have an advantage over customer contacts. And emerging FinTech companies should strive to build service trust, focused on young people with low resistance to new services.

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A Study on the Comparison and Analysis of Debris Reduction System on Small Bridge (소교량 유송잡물 저감시설의 비교 분석 연구)

  • Kim, Sung-Joong;Jung, Do-Joon;Kang, Joon-Gu;Yeo, Hong-Koo;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.31-41
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    • 2016
  • Damage to structures, such as bridge piers, are increasing rapidly due to the debris moving along rivers at the time of flooding. Therefore, the debris fin, debris deflector and debris sweeper, which are debris reduction systems, were produced in this study and an accumulation experiment was carried out on the experimental channel according to the existence of the reduction system. The debris fin is the reduction system that creates parallel flow on debris accumulated on the bridge to pass through the bridge, which was produced using wood. In addition, the debris deflector was produced using steel pipes and it has the type of detouring the direction of debris. The debris sweeper passes the debris using the magnetic force rotation of a screw-shaped cylindrical structure by water flow and it was produced using acrylic material. The experiment was carried out by analyzing the level of accumulation according to the hardness and dropping method of the debris and comparing the accumulation rate of reduction systems, and the experiment was carried out 5 times. According to the experimental results, there was a difference in the accumulation rate according to the type of reduction system and the shape of debris, and it often depended significantly on the initial shape of debris accumulation. The direct debris reduction effect on the bridge was higher in the order of the debris deflector, debris sweeper and debris fin, but in case of the debris deflector, damage, such as stream turbulence, changes in water level and river bed, and the loss of deflector can occur due to debris accumulated directly on the debris deflector. Therefore, it is necessary to design the debris deflector considering these issues.

An Application of Fuzzy AHP and TOPSIS Methodology for Ranking the Factors Influencing FinTech Adoption Intention: A Comparative Study of China and Korea (FinTech 채택 의도에 영향을 미치는 요소의 순위 결정을 위한 Fuzzy AHP 및 TOPSIS 방법론의 적용 : 중국과 한국의 비교 연구)

  • Mu, Hong-Lei;Lee, Young-Chan
    • Journal of Service Research and Studies
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    • v.7 no.4
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    • pp.51-68
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    • 2017
  • Financial technology (FinTech) is an emerging financial service sector include innovations in financial literacy and investment, retail banking, education, and crypto-currencies like bitcoin. One of the crucial branch of financial technology-third-party payment (TPP) is undergoing rapid growth, with online/mobile systems replacing offline financial systems. System quality and user attitudes are key perceptions driving third-party payment usage, the importance of these perceptions, however, may be different with countries as users' thinking varies from country to country. Thus, the purpose of this study is to elaborate how factors differ from China to Korea by drawing on the unified theory of acceptance and use of technology (UTAUT2). Additionally, this study also aims to propose a multi-attribute evaluation of the third-party online payment system based on analytic hierarchy process (AHP), fuzzy sets and technique for order performance by similarity to ideal solution (TOPSIS), to examine the relative importance of the perceptions influencing new technology adoption intention. The results showed that the price value has the most significant influence on Chinese perceptions, while the perceived credibility has the most significant effect on Korean perceptions. Sub-criteria also performs different results to Chinese and Korean third-party online payment system.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Study on the FinTech activation plan: The U.S., China, and Korea's Regulations (핀테크 활성화 방안 연구: 미국, 중국, 한국의 규제 현황 중심으로)

  • Kim, Sang-Won;Im, Seokjin
    • Journal of Industrial Convergence
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    • v.19 no.4
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    • pp.29-35
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    • 2021
  • Fintech, a new form of financial industry that converges IT, is developing rapidly in developed countries such as the US and China. The U.S. and China lowered barriers to entry through deregulation to develop and expand the fintech industry, and, for example, encouraged startup companies to incorporate various ideas through negative regulations that are more relaxed or do not apply regulations for a certain period of time. The U.S. and China did not apply existing financial regulations to the fintech industry, providing an environment where fintech startups could grow more easily. Currently, in Korea, fintech technologies such as 'Samsung Pay', 'Toss' and 'Kakao Pay' have been developed and are being activated, and also their scale is expanding. Although various systems are being reorganized and regulated for the development of Fintech, Fintech's growth rate is slow due to unfriendly and unopened regulations in the financial sector and various markets. This paper examines the status of fintech, focusing on advanced fintech and Korea, and examines fintech-related regulations that hinder the development of the fintech industry. We propose a more flexible way of easing excessive regulation in the financial sector, such as post-regulation.

A Taxonomic Revision of the Family Bagridae (Pisces, Siluriformes) from Korea (한국산 동자개과 어류의 분류학적 재검토)

  • Lee, Chung-Lyul;Kim, Ik-Soo
    • Korean Journal of Ichthyology
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    • v.2 no.2
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    • pp.117-137
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    • 1990
  • The morphological characters of the family Bagridae living in the river systems flowing into the south and western seas of Korea were reviewed and a taxonomic revision was made. The family Bagridae was classified into two genera: Pseudobagrus and Leiocassis. Species corresponding to genus Pseudobagrus were P. fulvidraco, P. koreanus Uchida, sp. nov., P. brevicorpus, and genus Leiocassis were L. nitidus, L. ussuriensis, and L. longirostris. Among them Pseudobagrus koreanus Uchida, sp. nov. and P. brevicorpus are endemic species of Korea. As the intergeneric taxonomic characters, the outstanding morphological differences between genera Pseudobagrus and Leiocassis were distinguished in following characters; the serrated structure of pectoral spine, the length of barbels, the number of pectoral fin rays, the structure of cranial lateral line system and the fused state of 3-4 hypurals. Pelteobagrus fulvidraco and Coreobagrus brevicorpus recorded previously in Korea were classified as Pseudobagrus fulvidraco and P. brevicorpus, respectively. Pelteobagrus nitidus and Pseudobagrus ussuriensis are also changed to genus Leiocassis. The characters of interspecific classification belonging to genera Pseudobagrus and Leiocasis were the shape of caudal fin, the form of body, the length of body, the number of anal fin ray and the number of gill rakers. Pseudobagrus sp. was named into Pseudobagrus koreanus Uchida, sp. nov..

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