• 설비공학논문집
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• 제25권2호
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• pp.109-118
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• 2013

The absence of a simple and general analytical model has been a problem in the design and analysis of desiccant-assisted air-conditioning systems. In this study, such an analytical model has been developed based on the approximate integral solution of the coupled transient ordinary differential equations for the heat and mass transfer processes in a desiccant wheel. It turned out that the initial conditions should be determined by the solution of four linear algebraic equations including the heat and mass transfer equations for the air flow as well as the energy and mass conservation equations for the desiccant bed. It is also shown that time-averaged exit air temperature and humidity relations could be given in terms of the heat and mass transfer effectiveness.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.291-294
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• 2006

Studies of the effectiveness of anthraquinone (AQ) in kraft-AQ pulping in terms of its mechanism of mass transfer have been conducted. Experiments performed have demonstrated an 'apparent solubility' of AQ in caustic solutions of wood lignin. The adsorption behavior of AQ species was also analyzed. Anthraquinone-2-sulfonic acid (AQ-S), a water-soluble derivative of AQ, showed selective adsorption on wood. A mechanism for the transport of AQ into wood chips during kraft pulping are proposed, and some explanations for previously unexplained observations are addressed.

• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.112-121
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• 2020

In this work energy and entransy characteristics of heat exchangers are analyzed for 12 different flow arrangements of heat exchangers. The dimensionless parameters are number of entransy dissipation (Ng), number of entransy dissipation-based thermal resistance (Nr), and entransy dissipation-based effectiveness of heat-exchanger (εg). The dimensionless parameters are expressed analytically in terms of the effectiveness of heat exchanger (ε), heat capacity ratio (c), and number of transfer unit (N) for optimal performance of heat exchangers. Results showed that the dimensionless parameters based on the entransy dissipation can be useful concepts for optimal design of heat exchangers.

• 설비공학논문집
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• 제12권9호
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• pp.853-859
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• 2000

In this study, low temperature waste heat recovery heat exchanger was developed using a principle of self-excited oscillating heat pipe. The heat exchanger of serpentine type was composed of extruded flat aluminum tube with 6 channels (3 nm$\times$ 2.75nm) and louvered fin. The heat transfer area density of heat exchanger was $331.9 m^2/m^3$. Working fluid is R141b and charge ratio was 40% by volume. Heat transfer rate and the effectiveness of heat exchanger was primary concern of this study. As a result, the effectiveness of heat exchanger was about 0.4-0.67, and recovered waste heat rate was about 4.5 kW per one unit of heat exchanger.

• 설비공학논문집
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• 제13권1호
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• pp.25-29
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• 2001

A study has been conducted to investigate the effect of the heat transfer surface position in the range of dropwise condensation, filmwise condensation, and glacial condensation. For dropwise condensation promoter, the heat transfer surface was evaporated by gold. As a result, heat transfer rate is almost same where the position of heat transfer surface is between 45 and 135 degree. It is found that heat transfer rate was reduced as subcooled degree was increased. And it is also found that if the subcooled degree becomes lower, the position of heat transfer surface is more effective. Adversely, if the subcooled degree becomes higher, the effectiveness of surface position is getting relatively lower. Regardless of the position, the transition temperatures from dropwise condensation to filmwise condensation is in the vicinity of 80K.

• Asian Journal of Innovation and Policy
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• 제9권3호
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• pp.257-280
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• 2020

The study analyzed the effectiveness of a technology transfer and commercialization support program to Korean technology transfer offices and firms. The study created a logic model to design a questionnaire to analyze how the support program, directly and indirectly, affected the technology transfer offices and the firms' performances. The study found that technology transfer offices are focused not only on potential firms' excavation activity to process the technology transfer but also on providing strategic support to provide practical assistance to the firms' needs. Not only has the number of technology transfer cases increased during the two-year program duration, but other activities, such as technical guidance and various strategic consulting for commercialization of the transferred technology, have also appeared to have increased considerably. Support program has helped strengthen the firms' internal capabilities, expand new market capabilities, and increase the firms' indirect performances.

• 아태비즈니스연구
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• 제10권4호
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• pp.197-204
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• 2019

The transfer pricing mechanism is a tool commonly used to transfer the tax base from countries with high taxation in countries with low taxation. In many countries, this financial operations generate significant tax revenue losses. In an attempt to limit tax revenue losses, many public authorities have introduced regulations on transfer pricing, but the effectiveness of these rules has proved limited, and they contributed to the increasing complexity of tax laws and to the appearance of additional costs for companies. Historically, transfer pricing (TP) was not a substantial issue in Mongolia. The tax legislation contains basic TP rules, but there is limited guidance and enforcement in practice. At the moment, Mongolian tax authorities are not conducting specific transfer pricing audits. Nevertheless, tax authorities are starting to pay more attention to transactions between related parties and potential transfer pricing adjustments. This study examines a transfer pricing regulations of Mongolia.

• 대한기계학회논문집B
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• 제33권7호
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• pp.520-526
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• 2009

The objectives of this paper are to measure the heat transfer and pressure drop of the plate heat exchangers for absorption system applications. Three types of plate heat exchangers with different chevron angles are tested in the present experiment. Heat transfer and pressure drop performance of plate heat exchangers are measured in various operating conditions, and compared each other. The results show that the heat transfer rate of high theta ($120^{\circ}$) and mixed theta plate heat exchanger increases about 118% and 98% at the solution flow rate 350 kg/h compared to that of low theta ($60^{\circ}$), respectively. The effectiveness of high theta was evaluated about $0.53{\sim}0.85$ in this experimental range. The experimental correlations of the Nu and f were developed with error bands of ${\pm}7%$ and ${\pm}12%$.

• 대한기계학회논문집
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• 제12권1호
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• pp.48-52
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• 1988

본 연구에서는 Carnot사이클로 작동되는 냉동사이클에 대하여 열교환과정 및 열손실을 고려하여 효율과 출력의 최대조건을 살펴 보고, 기존의 사이클 해석이 효율측면에서 실제장치와의 상이점으로 인하여 공학적 의미가 없어지는 문제점을 보완하고자 한다.

• 조명전기설비학회논문지
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• 제17권1호
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• pp.61-67
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• 2003

전력산업 구조개편시 효율적인 계통운용을 위하여 계산시간이 빠르고 신뢰적인 연계계통에서의 수송능력을 산정하는 알고리즘개발에 관한 연구는 필수적이라고 할 수 있다. 이를 위하여 본 연구에서는 효율적인 수송능력산정문제의 정식화 및 수송능력 산정시 초기 최대수송능력을 계산한 다음, 이로부터 계산된 발전기 출력의 초기값을 이용함으로써 수송능력계산의 수렴속도를 개선할 수 있는 방법을 제시하였다. 또한 이를 시험계통에 적용하여 본 연구의 타당성을 검증하고 유용한 정보를 도출하였다.