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Experimental Study on Surface Temperature Variation Characteristics of Rectangular Parallelepipeds Constructed by Different Materials for Varying Meteorological Conditions (기상 상태 변화에 따른 직육면체의 재질별 표면온도 변화 특성에 대한 실험 연구)

  • Kim, Dong-Geon;Choi, Jun-Hyuk;Kil, Tae-Jun;Kim, Jung-Ho;Kim, Tae-Kuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.2
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    • pp.208-214
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    • 2012
  • The spectral radiance received by a remote sensor is consisted of the self-emitted component directly from the target surface, the reflected component of the solar irradiance at the target surface, and the scattered component by the atmosphere without ever reaching the object surface. In general, the self-emitted component is the most important part in the infrared signatures from the target. We measured the solar irradiation, sky irradiation, air temperature, wind velocity, wind direction, relative humidity, and atmospheric pressure together with the surface temperatures of rectangular parallelepiped targets. The measured diurnal surface temperature variations on the three different rectangular parallelepiped targets constructed by the steel, aluminum and bakelite are obtained at the same time intervals. The measured surface temperature results show that the top surface temperature of bakelite recorded up tp $7.6^{\circ}C$ higher than that of aluminium and $6.1^{\circ}C$ higher than that of steel at 11 AM on the sunny condition. A complete set of measured data including the surface temperature of rectangular parallelepiped targets together with the detailed weather information can be a valuable reference for future study.

Analysis on Damage of Porcelain Insulators Using AE Technique (AE기법을 이용한 자기애자의 손상 분석)

  • Choi, In-Hyuk;Shin, Koo-Yong;Lim, Yun-seog;Koo, Ja-Bin;Son, Ju-Am;Lim, Dae-Yeon;Oh, Tae-Keun;Yoon, Young-Geun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.3
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    • pp.231-238
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    • 2020
  • This paper investigates the soundness of porcelain insulators associated with the acoustic emission (AE) technique. The AE technique is a popular non-destructive method that measures and analyzes the burst energy that occurs mainly when a crack occurs in a high-frequency region. Typical AE methods require continuous monitoring with frequent sensor calibration. However, in this study, the AE technique excites a porcelain insulator using only an impact hammer, and it applies a high-pass filter to the signal frequency range measured only in the AE sensor by comparing the AE and the acceleration sensors. Next, the extracted time-domain signal is analyzed for the damage assessment. In normal signals, the duration is about 2ms, the area of the envelope is about 1,000, and the number of counts is about 20. In the damage signal, the duration exceeds 5ms, the area of the envelope is about 2,000, and the number of counts exceeds 40. In addition, various characteristics in the time and frequency domain for normal and damage cases are analyzed using the short-time Fourier transform (STFT). Based on the results of the STFT analysis, the maximum energy of a normal specimen is less than 0.02, while in the case of the damage specimen, it exceeds 0.02. The extracted high-frequency components can present dynamic behavior of crack regions and eigenmodes of the isolated insulator parts, but the presence, size, and distribution of cracks can be predicted indirectly. In this regard, the characteristics of the surface crack region were derived in this study.

A Basic Study for Treating E.A.F. Dust by use of Waste Tire (폐타이어를 이용한 제강분진 처리를 위한 기초연구)

  • 황용길;이상화;이성룡;정석수;최재신;조충형
    • Resources Recycling
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    • v.4 no.4
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    • pp.59-69
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    • 1995
  • Distillation oI the dust generated during waste tue pyrolysis was perIomerl to rccover valuable metal sucll as zlnc. lead and iron. Pemcahilily and carnprcssivc tests were pursucd to ahlain the basic dala for cslraclian of zinc from the slntering propcrtp ol stccl making dusts and distilled carhon of waste tires as wcll as wastc pulp sludge mixlure hr~quet were investigated at various sinlcring lempcraturcs. Permeablllly rncieased with increastng amount of waste pulp in specil~cd istilled carhon due tn the fnrmat~ono f porusily in lhe sample TIE co~npress~vsctr ength showed the vanous values wlth different amDunl of dislilled-carhon adrlit~nilsa nd at diIIerenl sinlering tcmpcralures. X-ray diffifraction anvlyscs oI a hnquet rn~rhtre of steelmaking dusts(20Q didilled carhon and 10% waste pulp sblered ;>I SOOT) showcd thal the briquet consisted ot ZnO and Fc,O.,, hut was not found at the hriguet rintered at over 10OO'C. Crude zinc oxide sintered a1 IOOOC contained OZA Zn.

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Implementation on the Classifier for Differential Diagnosis of Laryngeal Disease using Hierarchical Neural Network (계층적 신경회로망을 이용한 후두질환 감별 분류기)

  • 김경태;김길중;전계록
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.1
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    • pp.76-82
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    • 2002
  • In this paper, we implemented on the classifier for differential diagnosis of laryngeals disease which is normal, polyp, nodule, palsy, and each step of glottic cancer using hierarchical neural network. We conducted on classifier of various vowels as /a/, /e/, /i/, /o/, /u/ from normal group, laryngeal disease group, each step of cancer group. The experimental result on classification of each vowels as follows. A /a/ vowel shows excellent classification result to the other vowels in regard to each Input parameters. Thus we implemented the hierarchical neural network for differential diagnosis of laryngeals disease using only /a/ vowel. A implemented hierarchical neural network is composed of each other laryngeals disease apply to each other parameter in each hierarchical layer. We take the voice signals from patient who get the laryngeal disease and glottic cancer, and then use the APQ, PPQ, vAm, Jitter, Shimmer, RAP as input parameter of neural networks.

Development of Image Process for Crack Identification on Porcelain Insulators (자기애자의 자기부 균열 식별을 위한 이미지 처리기법 개발)

  • Choi, In-Hyuk;Shin, Koo-Yong;An, Ho-Song;Koo, Ja-Bin;Son, Ju-Am;Lim, Dae-Yeon;Oh, Tae-Keun;Yoon, Young-Geun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.4
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    • pp.303-309
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    • 2020
  • This study proposes a crack identification algorithm to analyze the surface condition of porcelain insulators and to efficiently visualize cracks. The proposed image processing algorithm for crack identification consists of two primary steps. In the first step, the brightness is eliminated by converting the image to the lab color space. Then, the background is removed by the K-means clustering method. After that, the optimum image treatment is applied using morphological image processing and median filtering to remove unnecessary noise, such as blobs. In the second step, the preprocessed image is converted to grayscale, and any cracks present in the image are identified. Next, the region properties, such as the number of pixels and the ratio of the major to the minor axis, are used to separate the cracks from the noise. Using this image processing algorithm, the precision of crack identification for all the sample images was approximately 80%, and the F1 score was approximately 70. Thus, this method can be helpful for efficient crack monitoring.

Endobronchial Chondroid Hamartoma - A case report- (기관지 내 연골성 과오종 -1예 보고-)

  • Lee Song Am;Kim Jun Seok;Lee Tae Hoon;Lim So Dug;Hwang Eun Gu;Kim Yo Han;Hwang Jae Joon
    • Journal of Chest Surgery
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    • v.39 no.3 s.260
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    • pp.240-243
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    • 2006
  • Pulmonary hamartoma is a common benign tumor of the lung, but endobronchial hamartoma is a rare tumor. Although bronchoscopic rcemoval or removal by bronchotomy or sleeve resection with preservation of the lung may be possible, when irreversible lung damage has occurred because of chronic obstruction and pneumonitis, pulmonary resection may be indicated. We herein report a case of endobronchial hamartoma which was treated by left upper lobectomy. A 42-year-old female with 3-week history of cough and left chest pain visited our hospital. Bronchoscopy showed total occlusion of the orifice of the left upper lobe bronchus by a lobulated endobronchial tumor and bronchoscopic biopsy was failed due to bleeding. A left upper lobectomy was performed because of severe consolidation of the left upper lobe by chronic obstruction. The patient was discharged on postoperative 14th day.

Efficacy and Safety of Dexmedetomidine for Postoperative Delirium in Adult Cardiac Surgery on Cardiopulmonary Bypass

  • Park, Jae Bum;Bang, Seung Ho;Chee, Hyun Keun;Kim, Jun Seok;Lee, Song Am;Shin, Je Kyoun
    • Journal of Chest Surgery
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    • v.47 no.3
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    • pp.249-254
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    • 2014
  • Background: Delirium after cardiac surgery is associated with serious long-term negative outcomes and high costs. The aim of this study is to evaluate neurobehavioral, hemodynamic, and sedative characteristics of dexmedetomidine, compared with the current postoperative sedative protocol (remifentanil) in patients undergoing open heart surgery with cardiopulmonary bypass (CPB). Methods: One hundred and forty two eligible patients who underwent cardiac surgery on CPB between April 2012 and March 2013 were randomly divided into two groups. Patients received either dexmedetomidine (range, 0.2 to $0.8\;{\mu}g/kg/hr$; n=67) or remifentanil (range, 1,000 to $2,500\;{\mu}g/hr$, n=75). The primary end point was the prevalence of delirium estimated daily via the confusion assessment method for intensive care. Results: When the delirium incidence was compared with the dexmedetomidine group (6 of 67 patients, 8.96%) and the remifentanil group (17 of 75 patients, 22.67%) it was found to be significantly less in the dexmedetomidine group (p<0.05). There were no statistically significant differences between two groups in the extubation time, ICU stay, total hospital stay, and other postoperative complications including hemodynamic side effects. Conclusion: This preliminary study suggests that dexmedetomidine as a postoperative sedative agent is associated with significantly lower rates of delirium after cardiac surgery.

GaInP/GaAs 이중접합 태양전지의 전극 구조가 집광 효율에 미치는 영향

  • Jeon, Dong-Hwan;Kim, Chang-Ju;Gang, Ho-Gwan;Park, Won-Gyu;Lee, Jae-Jin;Go, Cheol-Gi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.272-272
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    • 2010
  • 최근 화합물반도체를 이용한 집광형 고효율 태양전지가 차세대 태양전지로서 주목을 받기 시작하였다. GaAs를 주축으로 하는 고신뢰성 고효율 태양전지는 높은 가격으로 인해 응용이 제한되어왔으나, 고집광 기술을 접목하여 태양전지 재료 사용을 수 백배 이상 줄이면서도 동시에 효율을 극도로 향상시킴으로써 차세대 태양전지로 활발히 개발되고 있다. GaAs 기판을 이용한 다중접합의 태양전지는 n-type GaAs 기판 위에 버퍼 층, GaInP back surface field 층, GaAs p-n 접합, AlInP 창층, GaAs p-n 접합의 터널접합층, 상부전지로서 GaInP p-n 접합, AlInP 창층 순서로 epi-taxial structure를 형성하고 전극과 무반사막을 구성한다. 이러한 태양전지의 효율을 결정하는 요인 중, 상부 전극은 전기적 및 광학적 손실을 일으키는 원인으로써 최소화되어야 한다. 그런데 이러한 이중접합 화합물 태양전지에 집광한 태양광을 조사할 경우, 태양광을 집광한 만큼 전류가 증가하게 되며 증가한 전류가 전극에 흐르면서 전기적 효율 손실을 유발하게 된다. 따라서, 집광형 화합물 반도체 태양전지의 전극에 의한 손실에 대한 연구가 선행되어 저항에서 손실되는 전력을 최소화하여야만 전기적 손실이 낮은 고집광 태양전지 개발이 가능하다. 본 논문에서는 먼저 전극 두께가 0.5${\mu}m$인 GaInP/GaAs 이중접합 태양전지 (효율 25.5% : AM1.5G)의 집광시 효율 변화에 대해서 연구하였다. 이후 이러한 효율 변화가 전극 구조의 최적화에 의해서 개선 될 수 있는지를 삼차원 모의실험을 통해서 확인하였다. 모의실험에는 Crosslight 사의 APSYS를 사용하였고, material parameter를 보정하여 실제 실험 결과에 근사 시킨 후 전극 구조에 대한 최적화를 하였다.

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A Study on Effect of Tobacco on Operation of Retail Store and Relevant Direction of Development (담배가 소매점 운영에 미치는 영향과 발전방향에 관한 연구)

  • Choi, Jong-Am;Kim, Hun-Yong;Kim, Dea-Sik
    • Journal of the Korean Society of Tobacco Science
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    • v.29 no.1
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    • pp.41-51
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    • 2007
  • This study was implemented to examine the effect of tobacco on operation of a retail store and propose a relevant direction to development of a retail store. In terms of an examination method, the questionnaire was conducted in respect of supermarkets and convenience stores(CVS) around the nation. As a result of analysis based on such questionnaire, although there was a little difference in between a supermarket and a convenience store, a similar result could be found in general. In other words, retailers selling tobacco regarded the tobacco as a medium to solicit customers. Since the significance of tobacco in terms of total sales volume was so high, without the tobacco, they might have suspend the business. Consequently, the effect of tobacco was enormous. In addition, under the premise that many regular customers should be acquired to develop such retail stores, it was found that it would be necessary to increase $15{\sim}20%$ in terms of a margin in tobacco, preserve the profit ratio by the government, make efforts to enhance a quality and design by a tobacco company, actively recommend a particular brand, and actively display a tobacco publicity booklet, etc. Moreover, the proper number of tobacco stores in comparison with habitual smokers was one per 200 persons. In respect of the most unreasonable tobacco policy, a minor-related system and a policy of increasing a tobacco price were named. Thus, under the premise that a medium such as tobacco is highly important with respect to an operation of retail store, it is necessary to pay a more careful attention to an improvement of a reasonable and equitable system to further develop a retail store.

Institutional Issues in Promoting Korean Spatial Data Exchange

  • Kim, Kam-Lae;Choi, Won-Jun
    • Korean Journal of Geomatics
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    • v.2 no.1
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    • pp.75-82
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    • 2002
  • The information system fields of spatial applications have rapidly grown during the last decade in Korea. Spatial data has been produced for a variety of systems without common standards until national GIS Committee defined the data exchange formats among spatial databases in the middle of 1990's. It aimed at promoting data sharing between the different systems in similar application fields. However, a considerable number of databases built prior to the introduction of the standards are not yet standard compliant but still play the roles of the main producers/consumers in the data collection field such as early developed huge AM/FM systems maintained by governmental organizations. The strong autonomy of these databases keeps their own data models, formats and descriptions from being standardized, which leads the sharing to a more difficult stage. Sharing is another way of data acquisition with least efforts and time away from direct collection. A data clearinghouse is the core module which directs users to the relevant data resources. The contents of datasets should be described with predefined metadata standards for precise indexing. Moreover, a number of technical problems have to be resolved for the common use of data between heterogeneous spatial database systems. However, the technical issues can be covered by the present information technologies. The difficulties persist in the political/institutional issues. Institutional issues are derived from the diverse sources such as political background, governmental policies, related laws and/or regulations. The paper will firstly make an analysis of current situation in terms of Korean policies, laws and regulations, secondly abstract the institutional issues from the situation analysis, lastly present guidelines for promoting spatial data sharing in Korea.

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