• Journal of the Korean Home Economics Association
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• v.37 no.4
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• pp.41-58
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• 1999

The purposes of this study were 1) to segment the market based on purchase frequency of products such as apparel, food, home electronics, life commodity in department store and low-price retailing, 2) to identify differences among segments in belief and attitude toward each store, purchase frequency of apparel items in each store and demographic variables. The data were collected via a self-administered questionnaire from 274 married women living in Seoul, Korea and analyzed by factor analysis, cluster analysis, one-way ANOVA and x$^2$-test. The results of this study were as follows: First, using cluster analysis on purchase frequency of products in each store, four groups were identified and labeled as department store patronage/ non-purchasers of apparel in low-price retailing(25.2%), purchasers of apparel in department store and low-price retailing(16.8%), low-price retailing patronage(30.3%) and non-purchasers of products in department store and low-price retailing(27.0%). Second, a series of one-way ANOV As revealed significant differences among four segments on beliefs of low-price retailing(four store attributes: price and variety of apparel product, facilities for convenient shopping, promotion, brand-reputation and fashionability of apparel product) and department store(three store attributes: price and variety of apparel product, facilities for convenient shopping and promotion) and attitude toward low-price retailing and department store. Attitude toward each store was yielded using Fishbein's multiattributes model. There were also significant differences among groups in purchase frequency of seven apparel items in low-price retailing and six apparel items in department store, and six demographic and personal variables(age, educational status, type of husband's occupation, monthly income and housing). Finally, the papers discussed manageral implications for each segments as well as theoretical implications.

• Journal of Internet Computing and Services
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• v.17 no.4
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• pp.87-93
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• 2016

Since aging population in Korea is rapidly progressing, the need for improving the life quality of the elderly has been increasing. Accordingly, in order to respond in a residential environment improvement and behavior change for the elderly, architecture design and construction methods have become converted into a modular construction method and various IT systems for the elderly have been proposed. Unlike current residential design techniques for the elderly in which architectural design techniques are performed separately with IT system design, the methodology for converging architectural design techniques with IT has not been discussed and proposed. Therefore, this paper extensively studies about requirements for converging architectural design techniques with IT such as elderly behavior, residential IT Service plan factor analysis, and residential modular construction method including IT services.

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.474-481
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• 2017

In Korea, foot-and-mouth disease has not been reported for several decades, but it began to develop again in 2000. For 2010~2011, when the worst occurred, 3.5 million animals were disposed of resulting in a loss of 2.8 trillion won. In order to prevent the harmful effects of foot-and-mouth disease, vaccination and housing management are being implemented. Despite these measures, foot-and-mouth disease is infected with air through the respiratory tract and accompanies fever after latency. Therefore, it is recognized that measuring and managing the body temperature of livestock at the early stage is the first step of managing this disease. In this paper, we propose a temperature monitoring system that can measure the body temperature by incorporating temperature sensor mounted in ear-tag of cattle and collect body temperature data of each individual cattle through BLE into the control server. The proposed body temperature monitoring system has various advantages such as easy installation without the help of livestock specialists and not damaging the organs of the livestock. So, it is possible to manage the abnormal symptom of cattle in real time and it is believed that the proposed monitoring system will revolutionize the prevention of foot-and-mouth disease.

• Design & Manufacturing
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• v.10 no.3
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• pp.14-19
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• 2016

Thermally or electrically conductive filler reinforced polymer composites are extensively being developed as the demand for light weight material increases rapidly in industiral applications need good conductivity such as heat sink of the electronics or light. Carbon or ceramic materials like graphite, carbon nanotube or boron nitride are typical conductive fillers with good thermal or electical conductivity. Using these conductive fillers, the polymer composites in the market show wide range of thermal conductivity from approximately 1 W/mK to 20 W/mK, which is quite enhanced considering the thermal conductivity lower than 0.5 W/mK for most polymeric materials. The practical use of these composites, however, is yet limited to specific applications because most composites are still not conductive enough or too difficult to process, too brittle, too expensive for higher conductivity. For practical use of conductive composite, the thermal conductivity required depending on the heat releasing mode are studied first for simplified unit cooling geometry to propose thermal conductivities of the composites for reasonable cooling performance comparing with the metal heat sink as a reference. Also, as a practical design for heat sink based on polymer composite, composite and metal sheet hybrid structures are investigated for LED lamp heat sink and audio amplication module housing to find that this hybrid structure can be a good solution considering all of the cooling performance, manufacturing, mechanical performance, cost and weight.

• Journal of IKEEE
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• v.24 no.1
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• pp.72-80
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• 2020

This paper describes the design and fabrication of a BUC(Block Up-converter) which is a component of a FST (Flyaway Satellite Terminal), one of the ET(Earth Terminal) of the military satellite. BUC is physically composed of an up-converter module, a high power amplifier module, a receive band suppression filter, a housing, and a cable assembly. It was designed using simulator AWR to satisfy the electrical characteristics of BUC's such as maximum output power, gain, unwanted signal, and intermodulation. The maximum output power and gain characteristics were measured at 43.4dBm and 51.8dB, respectively. The unwanted wave and intermodulation characteristics were -73.5dBc and -31.9dBc, respectively. Of the electrical requirements of Table 1, not only the above four but also all of the items were confirmed to be satisfied.

• Journal of IKEEE
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• v.24 no.1
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• pp.81-89
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• 2020

This paper describes the design and fabrication of a LNB(Low Noise Block downd-converter) which is a component of a FST(Flyaway Satellite Terminal), one of the ET(Earth Terminal) of the military satellite. LNB is physically composed of an down-converter module, a low noise amplifier module, a transmit band suppression filter, a isolator, a housing, and a cable assembly. It was designed using simulator (AWR) to satisfy the electrical characteristics of LNB's such as gain, noise figure and unwanted signal. The gain and noise figure characteristics were measured at 61.4dBm and 1.37dB, respectively. The unwanted wave was measured at -66.79dBc. Of the electrical requirements of Table 1, not only the above three but also all other items were confirmed to be satisfied.

• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.23-34
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• 2020

Concentrator photovoltaic (CPV) system consists of high-quality complex optical elements, mechanical devices, and electronics components and can have the advantages of high integration and high-efficiency energy sources. III-V compound semiconductor cells have proven performance based on high reliability in the aerospace field, but have characteristics that require absolute support of the balance of systems (BOS) such as solar position trackers, receivers with heat sinks, and housing instruments. To determine the optimum parameters of secondary optical elements (SOEs) design for CPV systems, we designed three types of CPV modules, classified as non-SOEs type, reflective mirror type, and CPC lens type. We measured the I-V and P-V characteristics of the prototype CPV modules with the angle of inclination varying from 0° to 12° and with a 500-magnification Fresnel lens. The experimental results assumed misalignment of the solar position tracker or module design of pinpoint accuracy. As a result, at the 0° tilt angle, the CPC lens produced lower power due to the quartz transmittance ratio compared to that by other SOEs. However, for tilt angles greater than 3°, the CPC lens type module achieved high efficiency and stability. This study is expected to help design high-performance CPV systems.

• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.226-231
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• 1999

Pyroelectric infrared sensors have been fabricated using P(VDF/TrFE) film with pyroelectric effect. The weight percent and thickness of the poled P(VDF/TrFE) film are 75/25 percent and $25\;{\mu}m$ respectively. For easier fabrication and connection method new top and bottom electrodes design was adapted for human body detecting pyroelectric infrared sensor. An aluminum infrared absorption electrode and bottom electrode were deposited by thermal evaporator. And the device was mounted in TO-5 housing to detect infrared light of $5.5{\sim}14\;{\mu}m$ wavelength. The responsibility, NEP (noise equivalent power) and specific detectivity $D^*$ of the device were $9.62{\times}10^5\;V/W$, $3.95{\times}10^{-7}\;W$ and $5.06{\times}10^5\;cm/W$ under emission energy of $13\;{\mu}W/cm^2$ respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.3
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• pp.214-223
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• 2015

This research aims to study agricultural dwelling welfare's application plan according to empty house reality condition. Study's subject was empty houses in Yeongwol-gul in year 2013. Data analysis was concentrated on measuring questionnaires and SPSSWIN 16.0 was used for statistics of frequency analysis and average analysis. As a result, first, empty house's background occurrence and environment was investigated. Second, due to dead mine and rural exodus, there was increase in the number of empty houses, which damaged regional scenary. Furthermore, the region became a crime-ridden district, which is a social issue. Third, it was found that plans as empty house remodeling, policy support, various alternatives, systematic management, housing welfare, and continuous promotion were needed. This research will provide implications in solving social issues due to empty houses, and through application plan, there will be improvement in agricultural dwelling welfare and income increase. There also will be improvement in environment, and policy source for inducing city people and original residents to empty houses.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.349-358
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• 2019

This paper aimed at collecting sensor signals to extract characteristic parameter of the rotor. A vibration test rig has been developed to perform model tests. Signal characteristics were analyzed when driving normally. Envelope FFT Analysis is used to extract vibration components caused by periodic impacts from other vibration factors. Signal analysis was performed when load changes were given to speed sensors and vibration test rigs that show low frequency characteristics of the rotor and signal analysis according to rotational speed. The acceleration signal measured in the bearing housing has a small amplitude and produces only the rotational frequency component and harmonic component of the motor. As the number of rotations increases, the amplitude of acceleration can be seen. As the rotational speed increases, it can be seen that there is a difference in the shape of the original data and compared with the acceleration FFT graph, it can be seen that the noise is strong at low frequencies and the corresponding rotational frequency components are clearly represented. It can be seen that changing the load does not increase the main rotational frequency component.