• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.1
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• pp.43-54
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• 1997

This paper presents an approximate analytical solution to a two-region one-dimensional model for the charging process of stratified thermal storage tanks with variable inlet temperature in the presence of momentum-induced mixing. Based on the superposition principle, an arbitrary-varying inlet temperature is decomposed into inherent discontinuous steps and continuous intervals approximated as a finite number of piecewise linear functions. This approximation allows the temperature of the upper perfectly-mixed layer to be expressed in terms of constant, linear and exponential functions with respect to time. Applying the Laplace transform technique to the model equation for the lower thermocline layer subject to each of three representative interfacial conditions yields compact-form solutions, a linear combination of which constitutes the final temperature profile. A systematic method for deriving solutions to the plug-flow problem having polynomial-type boundary conditions is also established. The effect of adiabatic exit boundary on solution behaviors proves to be negligible under the actual working conditions, which justifies the assumption of semi-infinite domain introduced in the solution procedure. Finally, the approximate solution is validated by comparing it with an exact solution obtained for a specific variation of inlet temperature. Excellent agreements between them suffice to show the necessity and utility of this work.

• Journal of Sasang Constitutional Medicine
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• v.15 no.1
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• pp.12-26
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• 2003

1. Purpose This study is intend to catch DongMu(東武)'s viewpoint of Chobongeun Soyangin prescription. 2. Method Through Comparing Chongeun Soyangin prescriptions and medications on those of DongEuiBoGam(東醫寶鑑), DongyiSooseBowon Gabobon and DongyiSooseBowon Sinchukbon, we can find DongMu(東武)'s viewpoint of Sasang Constitutional Medicine. 3. Results 1) The same Hi prescriptions between DongEuiBoGam(東醫寶鑑) and Chobongeun Soyangin are not entirely identical. 2) GamCho(甘草), GaengMi(粳米) and Sagunja(使君子) were used in the Chobongeun Soyangin prescriptions. that means DongMu(東武)'s viewpoint of Sasang Constitutional Medicine was not entirely established. 3) PaedockSan(敗毒散), VukmijihwangTang(六味地黃湯) and BaekhoTang(白虎湯) were representative prescriptions in the Chobongeun Soyangin prescriptions. And that prescriptions were connected to DongyiSooseBowon Sinchukbon. 4) The same kind medications which were record on DongEuiBoGam(東醫寶鑑) and Chobongeun Soyangin are eighteen. And that medications are the structural principle of Chobongeun Soyangin prescriptions.

• Korean Management Science Review
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• v.24 no.1
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• pp.1-24
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• 2007

The function of product design has been an important part for success on new product development. We deeply studied 'Chocolate-Phone' case which is considered as a representative of adopting design-oriented new product development strategy. According to this study, we found three contextual factors and nine key success factors for design-oriented new product development. The contextual factors consist of the strong needs for innovative product development, customer's needs for the emotional value, competitive situation for the new product launching. The key success factors consist of design, development, marketing, overall sides. The key success factors of design side are to select talented designers and take an insight for market and communication skill. The key success factors of development side are to possess high technological abilities, to do divergence with removing or giving up some function, management's strong support. The key success factors of marketing side are to bring core marketers from outside, capacity to gather ideas from outside. The key success factors of overall side are to share design-oriented principle with other functions and to change member's mind from engineer-oriented to market-oriented.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.1047-1056
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• 2020

The study investigates developing an Islamic student financing securitization model based on sukuk structures. This study employs sample of descriptive, analytical, and comparative analyses utilized to discuss a novel framework of Islamic securitization through the different structures of sukuk wakalah derived from asset securitization. The result served to investigate the use of Islamic student financing securitization in a Shariah-compliant manner, which would be implementable in Malaysia. It emphasized the sukuk structures based on the wakeel principle, which indicated a situation where a wakeel or representative appointment was made to manage a project on the behalf of the sukuk holder. The findings of this study supported the economic benefits obtained in the form of lower overall financing costs through the use of securitization for student financing in higher education. This paper offers important implications specifically for the creation of sukuk structures and issuing a highly graded and marketable sukuk, which are compliant towards global Shariah principles. The paper fills the gap perceived within the existing literature of Islamic finance by showing Islamic securitization via sukuk as a viable source of funds potential utilizable in stabilizing the securities market. It can also pose as a solution for securing a sustainable funding.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.1
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• pp.8-17
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• 2009

This paper proposes robust ship wake search method in the target evasion environment. Moving surface ships generate a long trailing wake in the rear of a surface ship. Wake homing torpedo sensing this wake can detect the surface target and engage it automatically. In wake homing torpedo, wake search method is important element to maximize effectiveness of wake homing torpedo. This paper proposes one-side, two-side and centering mode according to passing wake boundary scenarios. Also, wake deflection angle is deduced by using the principle of deflection angle of acoustic torpedo. The representative experimental results using monte-carlo simulation demonstrate that the searching method using one-side mode is superior to two-side and centering mode in the target evasion environment.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.41-45
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• 2011

The fire event occurred in fire proof zone often causes serious electrical problems such as shorts, ground faults, or open circuits in nuclear power plants. These would be directed to the loss of safe shutdown capabilities performed by safety related systems and equipments The fire event can treat the basic design principle that safety systems should keep their functions with redundancy and independency. In case of a cable fire, operators can not perform their mission properly and can misjudge the situation because of spurious operation, wrong indication or instrument. These would deteriorate the plant capabilities of safety shutdown and make disastrous conditions. In this paper, the cables of the representative nuclear power plant in korea is selected and the cable functional failure temperature by exposed fire using Cable Response to Live Fire(CAROLFIRE) is studied. It is expected that the results are very useful to know the cable failure temperature by exposed fire. We confirmed the safety and integrity of the cable by exposed fire and those results will use the based data of cable exposed fire characteristics.

• Cross-Cultural Studies
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• v.28
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• pp.37-53
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• 2012

This paper examines 'an active nihilism' in Suk-je Sung's novels in detail. The focus of this study is formed from the critical mind in a critical perspective that in Korean novels before and after 2000s, characters who embody 'problematic individuals' of $Luk{\acute{a}}cs$ have disappeared and those close to 'active nihilists' has become the mainstream. The most representative example of this phenomenon is Suk-je Sung's novels. 'Active nihilists' in his novels are described as 'ascetics' who mastered various spheres such as 'billiard', 'baduk gambling', 'alcohol', 'dance', and 'book collecting', and so on. In the sense that they reject the transcendental conditions of the modern world and live in the space and time of play in which they can display their passion and potentiality to the maximum, they beings jumping over the 'reality principle'. Also, what they want to repeat is not the endless exchange of labor and capital according to the capitalist system of exchange but rather the repeated existence of their power and passion. This 'anthropology of power and passion' is 'active nihilism' which could be expressed as the 'subject of creating new value' and 'Dionysian affirmation' by Nietzsche. Suk-je Sung's novels sharply prove the stylistic essence of 'a novel' which has to create its own form every time, constantly renewing the narrative style of the past ideal model. In this respect, they are very problematic and his innovation of a form draws the attention. Further, this will certainly be the important object of research in the diachronic dimension of contemporary Korean novel.

• Current Optics and Photonics
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• v.5 no.3
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• pp.298-305
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• 2021

Modern distance sensing methods employ various measurement principles, including triangulation, time-of-flight, confocal, interferometric and frequency comb. Among them, the triangulation method, with a laser light source and an image sensor, is widely used in low-cost applications. We developed an omnidirectional two-dimensional (2D) distance sensor based on the triangulation principle for indoor floor mapping applications. The sensor has a range of 150-1500 mm with a relative resolution better than 4% over the range and 1% at 1 meter distance. It rotationally scans a compact one-dimensional (1D) distance sensor, composed of a near infrared (NIR) laser diode, a folding mirror, an imaging lens, and an image detector. We designed the sensor layout and configuration to satisfy the required measurement range and resolution, selecting easily available components in a special effort to reduce cost. We built a prototype and tested it with seven representative indoor wall specimens (white wallpaper, gray wallpaper, black wallpaper, furniture wood, black leather, brown leather, and white plastic) in a typical indoor illuminated condition, 200 lux, on a floor under ceiling mounted fluorescent lamps. We confirmed the proposed sensor provided reliable distance reading of all the specimens over the required measurement range (150-1500 mm) with a measurement resolution of 4% overall and 1% at 1 meter, regardless of illumination conditions.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.703-708
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• 2022

K-means clustering is a representative clustering technique. However, there is a limitation in not being able to integrate the performance evaluation scale and the method of determining the minimum number of clusters. In this paper, a method for numerically determining the minimum number of clusters is introduced. The explained variance is presented as an integrated measure. We propose that the k-means clustering method should be performed in the subspace of the PCA in order to simultaneously satisfy the minimum number of clusters and the threshold of the explained variance. It aims to present an explanation in principle why principal component analysis and k-means clustering are sequentially performed in pattern recognition and machine learning.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.3
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• pp.139-149
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• 2022

In the automobile and shipbuilding industries, various materials and components require superior surface strength, excellent wear resistance and good resistance to repeated loads. To improve the surface properties of the materials, various surface heat treatment methods are used, which include carburizing, nitriding, and so on. Among them, carburizing treatment is widely used for structural steels containing carbon. The effective carburizing thickness required for materials depends on the service environment and the size of the components. In general, however, there is a limit in evaluation of the surface properties with a standardized mechanical test method because the thickness or cross-sectional area of the carburized layer is limited. In this regard, the nanoindentation technique has lots of advantages, which can measure the mechanical properties of the material surface at the nano and micro scale. It is possible to understand the relationship between the microstructural change in the hardened layer by carburizing treatment and the mechanical properties. To be spread to practical applications at the industrial level, in this paper, the principle of the nanoindentation method is described with a representative application for analyzing the mechanical properties of the carburized material.