• 대한전자공학회논문지
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• 제27권3호
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• pp.31-39
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• 1990

입력 디코더(decoder)가 달린 AND-EXOR형 PLA(programmable logic array)의 간단한 문제는 다치(Multiple-Value)입력 2치 출력 함수를 표현하는 ESOP(배타적 논리화를 이용한 적화형 논리식)의 간단한 문제에 대응한다. 본 논문에서는 5종류 적항의 변형 규칙(rule)을 이용한 ESOP의 간단한 알고리듬을 제안한다. 본 알고리듬에 의해 많은 산술회로의 데이타에 대해서 간단화를 행하였다. 그 결과, 1비트 입력디코더 및 2비트 입력디코더가 달린 PLA의 어느쪽에도 같은 예로써, AND-OR형 PLA 보다 AND-EXOR형 PLA의 쪽이 적은 적항수로 실현될 수 있었다.

• 전자공학회논문지D
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• 제35D권2호
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• pp.33-39
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• 1998

A six-beam accelerometer with self-compensated off-axis sensitivity was fabricated onthe selectively diffused (111)-oriented n/n$^{+}$/n silicon substrates by a unique porous silicon micromachining technique, which has self-stip characteristics and highly seletive formation of porous silicon layer during anodic reaction. Also, the characteristics of the fabricated accelerometer were investigated. The sensitivity of the acceleormeter added up outputs of three bridges through a summing circuit was 0.68 mV/g and the nonlinearity was less than 2% of the full scale output. The measured first resonant frequency was 4.236 kHz. When the outputs of three bridges were compared to summing output of bridges obtained through summing circuit, the normal output for Z-axis acceleration exhibited the same value s summing outputs of three bridges without reduction of sensitivity and thus the sensitivity decrease due to additional beam was compensated. Although a maximum off-axis sensitivity in one bridge of the accelerometer showed 17% of normal sensitivity, the off axis sensitivity obtained from summing output of three bridges decreased to 1.0%. Therefore, the self-elimination of off-axis sensitivity can be simply realized by obtaining the output of the sensor through summing circuit.t.

• 한국태양에너지학회 논문집
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• 제30권5호
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• pp.32-37
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• 2010

In order to handle the crisis about energy-environment problem, it is necessary to develop the future-oriented and innovative energy technology in architecture area. So the development of new technology for energy saving and alternative energy use has been spurred in this area. Double skin window system, which is an active covering to respond to the exterior change of the environment, is the skill that can reduce the indoor cooling and heating load and the environmental architecture can be realized. This study works out U-value of windows using the window-simulation program with the development and study of the double skin. In addition, the effect of the double skin insulation on the efficiency rating has been analyzed, applying to the certification system of the building energy efficiency rating which has implemented.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 하계학술연구발표회 및 한.일 공동심포지엄
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• pp.150-151
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• 2003

In the past years, a giant magnetoresistance (GMR) effect found in perovskite-like structured materials has attracted considerable attention among scientists and manufacturers, since, a practical point of view, the capacity of producing magnetic and sensing sensors. In a stream of this interest, further efforts to understand the underlying mechanism that leads to the GMR effect relative to the correlation between transport and magnetic properties, have been extensively devoted. In these cases, spin-glass-like behaviors are ascribed to the frustration of random competing exchange interactions, namely the ferromagnetic double-exchange interaction between Co$\^$3+/ (or Mn$\^$3+/) and Co$\^$4+/(or Mn$\^$4+/) and the antiferromagnetic one like spins. Noticeably, the distinction of spin-glass region from cluster-glass one, involved in the remarkable changes in transport and magnetic properties at a critical value of doping concentration, was observed. Magnetic anomalies in zero-field-cooled (ZFC) magnetization as well as ac magnetic susceptibility below Curie temperature T$\sub$c/ and the charge/orbital fluctuation were also realized. In this work, we present a study of magnetic properties of a deficient manganese perovskites system of La$\sub$0.6/Sr$\sub$x/MnTi$\sub$y/O$_3$, and particularly provide its new magnetic phase diagram.

• 설비공학논문집
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• 제25권11호
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• pp.573-577
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• 2013

An external window directly affects the energy performance of its building. In modern well-insulated buildings, U-values for walls of 0.36 $W/m^2K$ or even lower can be realized. In such buildings, glazing with typical U-value of 2.1 $W/m^2K$ or higher creates thermal weak spots on the facade. The performance of the existing triple glass window has been limited to energy savings and condensation prevention. In this study, the performance of condensation prevention of a vacuum multi-layer glass was analyzed. The final conclusion through mock-up experiments is as follows. The surface temperature of the vacuum multi-layer glass was $2^{\circ}C$ higher, and the temperature difference ratio (TDR) was 0.07 lower, than the corresponding values of the triple glass.

• 한국가정과학회지
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• 제3권2호
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• pp.135-153
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• 2000

Shoes originated from the practical purposes : to protect feet from heat, cold. etc., and developed into various shapes. representing ornamentation and hierarchy. It was revealed that the aesthetic value was differently manifested from the practical one by different natural environments and socio-cultural Phenomena of the times in the East and the West. Comparing shoes in the East with those in the West, this study finds out the origin of shoes in the East and the West, and shapes and characteristics of shoes through the changes of times. Investigating various kinds of shoes in the East and the West, it also finds out the differences in status representations. Shoes are classified into the following styles : in the West. (i) sandal in which the instep was almost exposed, tied with strips and fixed with band, (ii) closed shoes covering the instep, (iii) boots that arose above the ankle: in the East, (i) shoes without shoe neck (리) boots with shoe neck (화) and wooden shoes (극). Status was also represented in shoes. In the West. the status difference was manifested mainly by jewelry or embroidery ornamentation. In particular, it was realized by the way they tied the shoes in Rome and by the length of the pointed front of the shoes in Romanesque and Gothic period. In the East, China, Korea and Japan, on the other hand, the use of shoes was regulated in detail by the official costume system, where material and color played an important role in marking the status.

• 한국조리학회지
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• 제11권1호
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• pp.30-49
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• 2005

This study was done to figure out what sort of service quality the visitors of a theme park think much of. The service quality of theme park is the most important factor for customer's satisfaction, and such satisfaction can lead them to have repurchase intention. Most of the customers revisit a theme park on the basis of their own past experience and information through their friends, which means that service quality plays an important role in the theme park. The intention of revisit is strongly influenced by the primary factor of service quality and price. The neat appearances of its clerks, guideboard, buildings, structures, facilities and so on are the most important part in the properties of service quality. By the above mentioned strategy, the customer's devotion and the long-term expectation of profits could be realized. In other words, high qualified service is the basis of the service marketing for the theme park, contributes to enhancing customer's trust, and promotes communications about the theme park with one another in a friendly way. Besides, it can increase the number of visitors and cause the customers to perceive highly the value of the theme park.

• Journal of Welding and Joining
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• 제32권1호
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• pp.102-107
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• 2014

SCR(Thyristor) type $CO_2$ welders have widely used for the welding process of heavy industries such as shipbuilding and plant. Since the industrial fields of shipbuilding and plant are usually exposed to severe welding condition with lots of dust, extreme temperature, high humidity and vibration, it is not recommended to use inverter type welder despite its state-of-the-art technology. Many sophisticated functions in the inverter welder may not work due to malfunction of its sensitive components. Hence this study focused on digitalization of SCR $CO_2$ welder by making use of microprocessor for SCR phase control. By this application, fine control of output of the $CO_2$ welding systems is achieved. Also pulse output mode of operation is realized and its verification is carried out with aluminum sample welding. The experimental results showed sound weld bead. The front operation panel provide user with numerical parameter settings and monitors. It will help precise weld process monitoring and control with digital value.

• 전기화학회지
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• 제6권3호
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• pp.217-223
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• 2003

The present work is concerned with characterization of surface roughness and inhomogeneity of four kinds of hot-rolled carbon steels in terms of the fractal dimension and the depression parameter by using image analysis method and electrochemical impedance spectroscopy, respectively. From the analysis of the 3D AFM image, it is realized that all the hot-rolled steel surfaces show the self-affine fractal property. The values of the fractal dimension of the hot-rolled steels were determined by the analyses of the AFM images on the basis of both the perimeter-area method and the triangulation method. In addition, the Nyquist plots were found to be depressed from a perfect semicircle form. From the experimental findings, the changes in the values of the fractal dimension and the depression parameter with chemical composition have been discussed in terms of the change in the value of hardness of base steel.

• 한국초전도ㆍ저온공학회논문지
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• 제21권4호
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• pp.24-28
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• 2019

Despite the second generation HTS tapes (2G HTS tape) have limits in critical current value, scientific and electric devices require more current density day after day. These requirements are realized by using different superconducting wires that consist of 2G HTS tapes designed in various combinations. Authors of this paper have developed the numerical model for estimation of total critical current in the superconducting wire and critical current in each 2G HTS tape placed in this superconducting wire. The current drop in six 2G HTS tapes having different constructions was analyzed. The result of this research is the decrease of critical current up to 25 % for the stack of tapes and up to 5 % for the parallel tapes in the same plane. In addition, what was also made is the estimation of the current distribution by length for six 25 m 2G HTS tapes in different constructions and determination of current deviation by length of the wire.