• Transactions of Materials Processing
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• v.24 no.6
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• pp.418-425
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• 2015

Based on eco-friendly advantages and the enhanced development in the chemical and physical characteristics, liquid silicone rubber (LSR) is widely used in producing precision parts in the automotive, medical, electronics, aeronautical and many other industries. In the current work, a thermoplastic-thermoset multi component injection molding (MCM) was developed for a waterproof automotive connector housing using PBT and LSR resins. Measurements of the rheological characteristics of PBT and LSR were made to improve the reliability of the numerical analysis for the multi component injection process. With the measured viscosity, pvT and curing data, numerical analysis of the multi cycle injection molding was conducted using simulation software (Sigma V5.0).

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.730-733
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• 2005

본 연구는 신재생에너지의 하나인 태양광 발진의 소형 발전의 활용분야의 하나로 기존 정원 보안등의 전력원을 상용전원에서 태양전지로 변환하여 직용, 실증화한 연구 결과로서 태양전기 전원의 특성과 배터리의 노화, 반사갓의 차이점을 실증화 시험을 통하여 분석하였으며 각각의 실험결과들은 웹을 통하여 원격 모니터링이 가능하도록 시스템을 구성하였다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.4
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• pp.220-224
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• 2000

A new auscultation system for the detection of breath sound form trachea was developed in house. Small size microphone(panasonic pin microphone) was encapsuled in a housing for resonant effect, and hardware for the sound detection was fabricated. Pulmonary function test results were compared with the parameters extracted from frequency spectrum of breath sound obtained from the developed system. Results showed that the peak frequency and relative ratio of integral values between low(80∼400Hz) and high(400∼800Hz) frequency ranges revealed the significant differences. Developed system could be used for distinguishing normal subject and the patients who have pulmonary disease.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.9-12
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• 2001

Optical aligning process to archive the maximum optical coupling is crucial in many optical device manufacturing line such as laser diode module. Due to the three-dimensional nature of housing module and the aligning process for laser diode coupler, large amount of the manufacturing time, typically ranging from tens of minutes to an hour has to be devoted to the aligning process alone. In this thesis, we propose a new optical aligning process that employee a two-pass algorithm: coarse-to-fine search. Coarse search is a kind of blind search that finds the candidate region where the maximum optical coupling might mostly occur, followed by a fine searching that finds the maximum within the candidate region. The algorithm has been tested on 50 samples of cam-type laser diode modules, and the experimental results are analyzed in terms of aligning time and coupling efficiency.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.60-66
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• 2021

The antenna transmits and receives signals has a number of electronics that generate heat. For cooling, four fans and airways circulate air inside the antenna-equipped housing to exchange heat from the cooling plate assembly. In this study, fluid analysis was conducted to assess the suitability of the cooling system. The electronic components of the antenna exhibited temperature values lower than the maximum operating temperature of the components, which showed that the cooling system for the antenna had sufficient performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.763-769
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• 2010

In recent times, there has been considerable interest in HIPS (High Impact Polystyrene) materials for their use in construction of office equipments, home electronics, housing for electronics appliances, packing containers, etc. However, these materials suffer from problems caused by fatigue fracture. Further, their strength is substantially affected by environmental conditions. Therefore, in this study, the effect of temperature was analyzed by performing a tensile test and a fatigue test. It was observed that the yield strength, the ultimate strength, and the fatigue life decreased relatively with an increase in temperature. Further, an S-N curve can be predicted by using the results of the tensile test and a micro-Vickers hardness test.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.3
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• pp.132-136
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• 2014

We introduce a new architecture of TSK-based fuzzy inference system. The proposed model used fuzzy c-means clustering method(FCM) for efficient disposal of data. The premise part of fuzzy rules don't assume any membership function such as triangular, gaussian, ellipsoidal because we construct the premise part of fuzzy rules using FCM. As a result, we can reduce to architecture of model. In this paper, we are able to use four types of polynomials as consequence part of fuzzy rules such as simplified, linear, quadratic, modified quadratic. Weighed Least Square Estimator are used to estimates the coefficients of polynomial. The proposed model is evaluated with the use of Boston housing data called Machine Learning dataset.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.61-72
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• 2007

The purposes of this study were to summarize the concept of well-being and well-being apartment, to grasp the present condition of apartments which were introduced with well-being elements, and to find out the consumer preferences on well-being elements for apartment planning. Library and internet surveys were performed to summarize the concept of well-being and well-being apartment and to grasp the present condition of apartments which were introduced with well-being elements. Questionnaire survey was carried out from 2nd to 22nd of June 2005, to investigate the preferences on well-being elements for apartment planning. The respondents were 250 residents who are from thirties to fifties and living in urban area. As results, respondents think that 'living for health of body and mind' about concept of well-being and 'certificated apartments by green building rating system' or 'apartments introduced ecological factor' about concept of well-being apartment. They answered that 'yes' about 'Do you have intention to buy well-being apartment?'. The elements in aspect of complex planning having the preference were revealed that promenade for complex design, ecological garden or walking space for landscape design, outdoor exercise space for outdoor design, and security system for foundation equipment. The elements having the preference in aspect of public facilities were fitness room for sports & health facility and study room for cultural facility. The preferred elements in aspect of building and unit design were roof garden for building design, multi-functional room for unit floor plan, natural surface material for interior surface, ventilation system for indoor environment, control system for home automation, and food waste machine for home electronics.

• Journal of IKEEE
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• v.24 no.3
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• pp.766-776
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• 2020

Recently, as interest in machine learning (ML) has increased and research using ML has become active, it is becoming more important to find an optimal hyperparameter combination for various ML models. In this paper, among various hyperparameters, we focused on ML optimizers, and measured and compared the performance of major optimizers using various datasets. In particular, we compared the performance of nine optimizers ranging from SGD, which is the most basic, to Momentum, NAG, AdaGrad, RMSProp, AdaDelta, Adam, AdaMax, and Nadam, using the MNIST, CIFAR-10, IRIS, TITANIC, and Boston Housing Price datasets. Experimental results showed that when Adam or Nadam was used, the loss of various ML models decreased most rapidly and their F1 score was also increased. Meanwhile, AdaMax showed a lot of instability during training and AdaDelta showed slower convergence speed and lower performance than other optimizers.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.265-272
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• 2019

In this study, we conducted a prediction study to qualitatively identify the continuous growth rate that causes problems every year for deposit bank mortgage loans, identify the characteristic factors that could once again stabilize, and come up with measures for future quantitative analysis of mortgage loans and growth trends. Based on data analysis using the R program, which is widely used for big data analysis, the parameters of ARIMA model (0.1,1)(0.1,1)[12] were found to be most suitable. In these indicators, estimates over the next five years (60 months) increased 4.5% on average. However, this has limitations that do not reflect socio-environmental factors, which require further study of these limitations.