• 보존과학연구
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• 통권6호
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• pp.247-258
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• 1985

Conservation laboratory was attached to Keimyung University Museum inMarch 1980 and ever since it has been devoted mainly to the processing andconservation of metal objects. A number of objects have been processed inthis laboratory during the period, including those already in the collection ofthe Museum, those which were discovered during the three major excavationsof Kaya tombs conducted by the Museum, and those processed on commissionfrom other museums in the country,The activities of this laboratory include: (1) conserving the objects againstfurther erosion; (2) raising the archaeological value of the objects by revealingthe structure of such parts of the objects as concealed under rust; and (3)recovering the original shape of damaged objects.The methods adopted by the laboratory include: (1) removing from theobjects the ionized chlorine which usually are the major cause of erosion; (2)strengthening the objects by soaking them in acrylic resins; and (3) applyingresins to the surface of the objects to protect them from further erosion.Chemicals much employed by the laboratory includes the acrylic resin(Ruschot; developed jointly by the Cultural Property Research Institute ofKorea and Samwha Paint Company), the sodium sesquicarbonate, the sodiumhydroxide, the lithium hydroxide, and the benzotriazole.Major apparatus in the laboratory includes the vacuum immersion tank, theairbrasive, the ultrasonic cleaner, the pH-ion meter, the water bath, the zoomstereo microscope, the drying oven, and the drill.

• 한국해양공학회지
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• 제24권6호
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• pp.92-96
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• 2010

Recently, the application of aluminum alloys has been increasing for lightweight and high quality transport vehicles. Therefore, the proposal has been made to apply high speed hybrid welding methods to the marine grade aluminum alloy (A5052) used for shipbuilding by combining a 3-KW CW Nd : YAG laser and the MIG welding process. In this study, the characteristics of the welding parameters were investigated for a hybrid butt joint. This paper also describes the determination of the heat distribution in a weldment and the welding residual stress using a finite element method. Mechanical experimentation was also used to ascertain the reliability of the weldment.

• 한국소음진동공학회논문집
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• 제19권4호
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• pp.335-346
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• 2009

As the economy has grown and the main industry in Korea has been changed from secondary industry to tertiary industry, the importance of indoor environment has been a matter of common concern, in which one of the main concerns is to improve the indoor acoustic conditions. However, even though this is required more than before, there are no measures to protect the human being from the noise of electric home appliances. This is owing to the absence of the data about sound power level of electric home appliances. So, we investigate the sound power level of them and analyze the acoustical characteristics of each one. First, we tried to investigate the sound power measurement method of each electric home appliance. After it we test the sound power level of them. From the survey, we can know that the vacuum cleaner is the most noisy electric home appliance, and the refrigerator is the least noisy one. This results will help us predict the indoor noise level using the basic data of sound power level.

• Journal of Welding and Joining
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• 제30권5호
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• pp.13-15
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• 2012

Stainless steels is widely used in various industries due to its high strength and excellent corrosion resistance. However, in the case of fusion welding for stainless steel, chromium deficiency layer produced by chromium carbide precipitation during welding process causes corrosion-resistance to be lower and formation of intergranular corrosion. It requires a inevitable complex procedure such as pre-heating and post-heating process etc. to prevent such weld defects. From this viewpoint, the new welding process such as a solid state welding method is suited for welding of stainless steels due to its advantages over the fusion welding. Therefore this paper intends to investigate the research trend on friction stir welding, one of solid state welding processes for stainless steels.

• 한국대기환경학회지
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• 제22권5호
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• pp.719-723
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• 2006

House dust mite was the most important cause of allergic asthma and rhinitis. More than 70% of Korean children and about 50% of adult with respiratory allergy were sensitive to house dust mite. This experiment was indoor environment in house and house dust mite existence inquiry. From 23rd December 2005 to 28th February 2006, dust samples were collected from the bedclothes by a vacuum cleaner and air sampler And the levels of Der f1 and Der p1 were determined by ELISA((Enzyme-Linked Immunosorbent Assay). The results were as follows : 1 The dust mites allergy contaminations of bedclothes in house were higher than international standards(2000 ng/g). 2. In type of dust mite, the Korean house the almost have the D. farinae other than D. pteronyeeinus of mite. 3. The Der f1 and Der p1 levels per gram of dust from the bedclothes were 2074.99 ng on average, but they did not exist in air. The concentrations of house dust mite were significantly high in the bedclothes. This results suggest that the bedclothes have enough concentrations of dust mites to develop the sensitization. The control of indoor environment should be emphasized to prevent the sensitization by the repeated exposure to dust mite.

• 디자인학연구
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• 제12권1호
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• pp.5-12
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• 1999

본 연구는 편형별 아파트의 신발장에 대한 실태를 조사하여 향후 아파트 분양 시 제공되는 신발장의 기초자료를 제공하고 디자인 제안을 하는데 목적을 두었다. 이를 위해 현재 아파트 신발장의 사용실태, 거주자 만족도, 실측을 통한 신발장의 규모 및 내부구성 등을 파악하였고, 이를 근거로 각 평형별 신발장을 제안하였다. 제안의 초점은 우선 각 수납물품의 종류에 따라 가구의 내부 구성을 달리한 유니트를 개발한 후 이를 모듈화 한다는 것이다. 모듈의 단위는 거주자들의 불만요인을 분석하는 한편 일반적인 신발외 길이, 폭, 높이에 의거하였으며 이를 가족의 수나 수납물품의 양 그리고 아파트 규모에 따라 자유롭게 선택할 수 있도록 하였다. 본 연구에서는 이에 대한 여로 각 평형에 따라 일반적인 신발장의 규모를 설정하고 필요한 유니트를 선택한 결과를 제시하였다.

• 한국컴퓨터정보학회논문지
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• 제22권7호
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• pp.17-29
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• 2017

IRecently, researches on the recognition of indoor user situations through various sensors in a smart home environment are under way. In this paper, the case study was conducted to determine the operation of the robot vacuum cleaner by inferring the user 's indoor situation through the operation of home appliances, because the indoor situation greatly affects the operation of home appliances. In order to collect learning data for indoor situation awareness model learning, we received feedbacks from user when there was a mistake about the cleaning situation. In this paper, we propose a semi-supervised learning method using user feedback data. When we receive a user feedback, we search for the labels of unlabeled data that most fit the feedbacks collected through genetic algorithm, and use this data to learn the model. In order to verify the performance of the proposed algorithm, we performed a comparison experiments with other learning algorithms in the same environment and confirmed that the performance of the proposed algorithm is better than the other algorithms.

• 한국전기전자재료학회논문지
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• 제21권2호
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• pp.182-187
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• 2008

This paper dealt with the detection algorithm of series arcing, which is a cause of electric fires in low-voltage wiring systems. To find the distinguished electrical features of series arc, we simulated series arcing by the arc generator specified in UL1699. An electric heater, an inverter-controlled vacuum cleaner, and a phase-controlled incandescent lamp were used as loads to generate series arcing. A high-pass filter (HPF) with the low cut-off frequency of 3 kHz at -3 dB was fabricated and applied to separate the series arc signal from the AC voltage source. The experiment showed that the high frequency signal generates randomly during series arcing, and the phase-controlled incandescent lamp produces high frequency pulses even in normal state. In this case, the magnitude, the width, and the randomness of high frequency signal should be analyzed to estimate series arcing precisely.

• 한국정보시스템학회지:정보시스템연구
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• 제32권3호
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• pp.133-150
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• 2023

Purpose This study aims to develop classification models using a decision tree algorithm to identify core keywords and rules influencing online consumer review evaluations for the robot vacuum cleaner on Amazon.com. The difference from previous studies is that we analyze core keywords that affect the evaluation results by dividing the subjects that evaluate online consumer reviews into self-evaluation (star ratings) and peer evaluation (helpfulness votes). We investigate whether the core keywords influencing star ratings and helpfulness votes vary across different products and whether there is a similarity in the core keywords related to star ratings or helpfulness votes across all products. Design/methodology/approach We used random under-sampling to balance the dataset. We progressively removed independent variables based on decreasing importance through backwards elimination to evaluate the classification model's performance. As a result, we identified classification models that best predict star ratings and helpfulness votes for each product's online consumer reviews. Findings We have identified that the core keywords influencing self-evaluation and peer evaluation vary across different products, and even for the same model or features, the core keywords are not consistent. Therefore, companies' producers and marketing managers need to analyze the core keywords of each product to highlight the advantages and prepare customized strategies that compensate for the shortcomings.

• 환경위생공학
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• 제16권4호
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• pp.9-20
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• 2001

The objective of this study was to improve sanitary conditions at the beauty shops by informing the owners and employees to be aware of the public health. The data were obtained by the Physical investigation (August 1 to 30, 2001) of the sanitary Problems at 112 beauty shops in Daegu Metrpolitan area and by the surveys from the employees and customers. By analysis these data with SAS/PC+(ver. 6.12) and $x^2-test$, we have obtained the following results. 1. The numbers of the beauty shop workers (67.86% of the shops) were two including the owner, and only 18.75% of the workers had the regular public health training session. Even at the training sessions, no public health specialist was available as an instructor. 2. Sanitary conditions of the floor (92.76%), washer (88.93%) and rest room (74.11%) at the beauty shops were satisfactory. However, only 3.57% of the beauty shop used the vacuum cleaner that would be far more effective than the bloom to remove hairs from the floor. 3. About 91.07% (102 shops) did not or poorly sterilize equipments, and 91.76% (103 shops) did not store the sterilized or non-sterilized equipments separately. The shops that had the ultraviolet sterilizer that is required by the public health regulation were 53.57% (60 shops), and only 2.67% (3shops) actually used it. 4. About 82.14% (72 shops) used Oxyclean and detergent for washing the fabrics such as towels and gowns. About 11.61% (13 shops) used only detergent and 3.57% (4 shops) used the boiling sterilization method. No shop used the customer gown once per customer, and only 2.68% (3 shops) washed the used gown daily.