• Journal of Advanced Marine Engineering and Technology
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• 제28권8호
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• pp.1203-1210
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• 2004

It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.

• 대한후두음성언어의학회지
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• 제23권1호
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• pp.18-20
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• 2012

Over the last 30 years or so, it has been recognized that neurologic disorders could impair laryngeal function, and that neurogenic etiology could be discerned frequently. This has led collaborations between laryngologists and neurologists and focus on the management of neurogenic dysfunction of the larynx and pharynx, including central and peripheral disorder. The author introduced anatomical structure, nerve distribution and neurophysiology of the larynx for understanding its basic functions. The symptoms, diseases from laryngeal dysfunction and the development of diagnosis and management were also discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.434-436
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• 2001

한국의 배전선로 자동화시스템은 기술발전과 경제성을 고려하여 대규모와 소규모 시스템으로 나누어져 개발되어 설치 운영되고 있으며, 2001년 말까지 173개 사업소에 소규모 시스템이 설치 완료될 예정이다. 2002년부터는 서울시내를 시작으로 대규모 시스템이 설치되고 대도시를 중심으로 점차 소규모 시스템도 업그레이드 할 계획이므로 금년은 중대한 전환점이라 할 수 있다. 따라서 그동안의 배전선로 자동하 추진현황을 살펴보고 문제점을 고찰해 보았다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1155-1158
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• 1993

Proficiency in creating a knowledge base is required for high accuracy fuzzy control. To overcome this a fuzzy inference method is proposed that take these membership functions from the probability densities showing the distribution of the mesurement values. And a method using a rough fuzzy knowledge base automatically created from the basic measurement data and tuned using the gradient method is proposed. In actual tests, these were applied to automatic high accuracy adjustment devices for magnetic head and for high frequency circuits with good results.

• 한국정밀공학회지
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• 제25권6호
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• pp.7-12
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• 2008

• 한국응용곤충학회지
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• 제48권2호
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• pp.165-170
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• 2009

본 연구는 월동하는 끝동매미충의 충태별 분포를 두폭측정법을 활용하여 분석하였다. 끝동매미충 1령, 2령, 3령, 4령 및 5령 약충에 대한 두폭크기는 각각 0.381, 0.502, 0.673, 0.879 및 1.128mm였으며, 변이계수는 5.3, 4.0, 3.0, 4.5 및 5.3%였다. 성장률은 2령, 3령, 4령 약충에서는 1.31${\sim}$1.34로 큰 차이가 없었지만 5령에서 1.28로 약간 감소하였다. 두폭측정값의 회귀식을 구한 결과, LogY = 1.4627+0.1192X($r^2=0.9993$)으로 고도의 유의성이 인정되었고, Dyar 공식에 의한 적합도는 98% 이상으로 매우 적합하였으며, Dyar 계수(K)는 1.316이었다. 월동하는 끝동매미충의 밀도 및 충태 변화를 조사한 결과, 2006년 1월 하순에 0.25 $m^2$ 당 195마리가 채집되어 밀도가 가장 높았고, 월동 충태 조사에서는 90% 이상이 4령 약충이었다. 3월 중순부터 5령 약충의 발생량이 증가하였고, 월동 후 첫 성충발생은 4월 상순이었다.

• 대한청각학회지
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• 제24권1호
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• pp.29-34
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• 2020

Background and Objectives: Bilateral microphones with contralateral routing of signal (BiCROS) hearing aid is an option for hearing rehabilitation in individuals with asymmetric sensorineural hearing loss (ASNHL). The clinical factors influencing the trial and purchase of BiCROS were investigated. Subjects and Methods: We reviewed the medical records of 78 patients with ASNHL who were recommended to use BiCROS and analyzed the demographic and audiological factors influencing the trial and purchase of BiCROS. Results: Among the 78 patients, 52 (66.7%) availed of the free BiCROS trial and 21 (26.9%) purchased BiCROS. The mean pure tone audiometry (PTA) air conduction (AC) threshold of the better- and worse-hearing ears were 44.2±12.8 dB and 90.7±22.5 dB HL, respectively. The decision for trial or purchase of BiCROS was not influenced by age, sex, duration of hearing loss of the worse-hearing ear, or PTA AC threshold or speech discrimination score of both ears. The first and third quartiles of the PTA AC thresholds for the better-hearing ear of BiCROS buyers were 38.75 dB and 53.75 dB HL, respectively. The counterpart values for the worse-hearing ear were 72.50 dB and 118.75 dB HL, respectively. Conclusions: The clinical factors analyzed in this study were found to be irrelevant to the trial and purchase of BiCROS in patients with ASNHL. Nevertheless, the distribution range of the auditory thresholds of the subjects using BiCROS can be a useful basis for the counseling of patients with ASNHL and selection of candidates for BiCROS use.

• 대한영상의학회지
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• 제82권5호
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• pp.1246-1257
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• 2021

목적 본 연구의 목적은 두경부암의 종격동 림프절 전이의 예측인자와 영상 소견을 알아보고자 함이다. 대상과 방법 이 연구에서 저자들은 두경부암 환자 중에서 종격동 림프절 전이그룹과 비전이 그룹 사이의 임상 소견 및 질병의 특성(성별, 연령, 원발성 종양 부위, 조직학적 유형, 악성종양에 대한 이전 치료이력, T-, N- 및 M- 단계, 경부 림프절 전이) 들을 비교하였다. 또한 저자들은 전이그룹에서 종격동 림프절 분류에 따라 림프절 전이의 흉부 전산화단층촬영(전이분포와 림프절 최대직경) 및 양전자방출단층촬영/전산화단층촬영(최대 표준섭취계수)의 소견을 평가하였다. 결과 두경부암 환자 470명 중 55명(11.7%)에서 150개의 종격동 station을 포함하는 종격동 림프절 전이가 발견되었다. 하인두암, 재발한 종양, T4, N2/N3, 및 M1 단계는 종격동 림프절 전이의 의미 있는 예측인자로 평가되었다. 종격동 림프절 전이의 가장 흔한 위치는 일측 station 2 (상부기관주위 림프절, 36.4%), 일측 station 11 (엽간 림프절, 27.3%), 일측 station 10(폐문 림프절, 25.5%) 순이었다. 결론 하인두암, 재발성 종양 및 높은 TNM 단계인 경우, 두경부암의 종격동 림프절 전이 가능성을 고려하여야 한다.

• 소성∙가공
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• 제21권7호
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• pp.447-452
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• 2012

This paper is concerned with forming of Al-Zn-Mg-Sc aluminum alloy bolts, focusing on the effects of heat treatment and age-hardening on the formability and ductile damage evolution. Both experimental and finite element studies were performed. From the experiments, it is observed that the heat treatment or the normalization of Al-Zn-Mg-Sc aluminum alloy increases its formability dramatically resulting in successful bolt forming, while the effects of age-hardening at room temperature on the stress-strain relationship and formability are not very critical. Deformation characteristics such as distribution of effective stress and strain, material flow, and ductile damage evolution during bolt forming are examined using a commercial finite element package, Deform-2D. It should be noted that the extrusion load predicted by the finite element method matches well the experiment results. The finite element predictions on the deformation characteristics support the experimental observations such as fracture of bolt head flange, material flow, and distribution of hardness.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.89-94
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• 2002

n general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Uneven flow distribution can also increase or decrease the power consumption with a change in total developed head. To avoid these sump problems pump station designers are considered intake structure dimensions, such as approaching upstream, baffle size, sump width, width of pump cell and so on. From this background, flow characteristics of intake within sump are investigated numerically to obtain the optimal sump design data. The sump model is designed in accordance with HI code.