• 제목/요약/키워드: Internal loss

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SEA 기법을 이용한 저중량 대시판넬 흡,차음재 성능에 대한 연구 (Acoustic Study of light weight insulation system on Dash using SEA technique)

  • 임효석;박광서;김영호;김인동
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.51-55
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    • 2007
  • In this paper Statistical Energy Analysis has been considered to predict high frequency air borne interior noise. Dash panel Insulation is major part to reduce engine excitation noise. Transmission loss and absorption coefficient are considered to predict dash insulation performance. Transmission lose is derived from coupling loss factor and absorption coefficient is derived from internal damping loss factor. Material Biot properties were used to calculate each loss factors. Insulation geometry thickness distribution was hard to measure, so FeGate software was used to calculate thickness map from CAD drawing. Each predicted transmission losses between conventional insulation and light weight insulation were compared with SEA. Transmission loss measurement was performed to validate each prediction result, and it showed good correlation between prediction and measurement. Finally interior noise prediction was performed and result showed light weight insulation system can reduce 40% weight to keep similar performance with conventional insulation system, even though light weigh insulation system has lower sound transmission loss and higher absorption coefficient than conventional system.

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Retrospective clinical study of an implant with a sandblasted, large-grit, acid-etched surface and internal connection: analysis of short-term success rate and marginal bone loss

  • Lee, Jae-Wang;An, Jun Hyeong;Park, Sang-Hoon;Chong, Jong-Hyon;Kim, Gwang-Seok;Han, JeongJoon;Jung, Seunggon;Kook, Min-suk;Oh, Hee-Kyun;Ryu, Sun-Youl;Park, Hong-Ju
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제38권
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    • pp.42.1-42.7
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    • 2016
  • Background: The purpose of this retrospective study was to evaluate the clinical utility of an implant with a sandblasted, large-grit, acid-etched (SLA) surface and internal connection. Methods: Six patients who received dental implants in the Department of Oral and Maxillofacial Surgery, Chonnam National University Dental Hospital, were analyzed by factors influencing the success rate and marginal bone loss. Factors included patient's age, sex, implant installation site, whether bone graft was done, type of bone graft materials, approaching method if sinus lift was done, and the size of the fixture. In addition, the marginal bone loss was analyzed by using a radiograph. Results: All implants were successful, and the cumulative survival rate was 100 %. Average marginal bone loss of 6 months after the installation was 0.52 mm and 20 months after the functional loading was 1.06 mm. Total marginal bone resorption was 1.58 mm on average. There was no statistically significant difference in mesial and distal marginal bone loss. Conclusions: The short-term clinical success rate of the implant with an SLA surface and internal connection was satisfactory. Moreover, the marginal bone loss was also consistent with the implant success criteria.

단순반복염기서열의 변이 형태에 따른 위암 내시경 조직의 유전자형 분류 (Classification of Microsatellite Alterations Detected in Endoscopic Biopsy Specimens of Gastric Cancers)

  • 최영덕;최상욱;전은정;정정조;민기옥;이강훈;이성;유문간
    • Journal of Gastric Cancer
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    • 제4권2호
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    • pp.109-120
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    • 2004
  • Purpose: Individual gastric cancers demonstrate complicated genetic alterations. The PCR-based analysis of polymorphic microsatellite sequences on cancer-related chromosomes has been used to detect chromosomal loss and microsatellite instability. For the purpose of preoperative usage, we analyzed the correspondance rate of the microsatellite genotype between endoscopic biopsy and surgical specimens. Materials and Methods: Seventy-three pairs of biopsy and surgical specimens were examined for loss of heterozygosity and microsatellite instability by using 40 microsatellite markers on eight chromosomes. Microsatellite alterations in tumor DNAs were classified into a high-risk group (baselinelevel loss of heterozygosity: 1 chromosomal loss in diffuse type and high-level loss of heterozygosity: 4 or more chromosomal losses) and a low-risk group (microsatellite instability and low-level loss of heterozygosity: 2 or 3 chromosomal losses in diffuse type or $1\∼3$ chromosomal losses in intestinal type) based on the extent of chromosomal loss and microsatellite instability. Results: The chromosomal losses of the biopsy and the surgical specimens were found to be different in 21 of the 73 cases, 19 cases of which were categorized into a genotype group of similar extent. In 100 surgical specimens, the high-risk genotype group showed a high incidence of nodal involvement (19 of 23 cases: $\leq$5 cm; 23 of 24 cases: >5 cm) irrespective of tumor size while the incidence of nodal involvement for the low-risk genotype group depended on tumor size (5 of 26 cases: $\leq$5 cm; 18 of 27 cases: >5 cm). Extraserosal invasion was more frequent in large-sized tumor in both the high-risk genotype group ($\leq$5 cm: 12 of 23 cases; >5 cm: 23 of 24 cases) and the low-risk genotype group ($\leq$5 cm: 7 of 26 cases; >5 cm: 16 of 27 cases). The preoperative prediction of tumor invasion and nodal involvement based on tumor size and genotype corresponded closely to the pathologic tumor stage (ROC area >0.7). Conclusion: An endoscopic biopsy specimen of gastric cancer can be used to make a preoperative genetic diagnosis that accurately reflect the genotype of the corresponding surgical specimen.

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췌장 가성낭종 환자 치험 1례 (A Case of Pancreatic Pseudocysts with Oriental Medical Treatment)

  • 허원영;류봉하;김유승;홍인아;김소연;엄국현;이선령;윤상협
    • 대한한방내과학회지
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    • 제28권4호
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    • pp.963-971
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    • 2007
  • A pancreatic pseudocyst is the most common cystic lesion in the pancreas. There are several treatment methods with variable results. Recently, conservative treatment has been preferred because it has fewer complications. In this case, a 37-year-old male patient had pancreatic pseudocysts with upper abdominal pain, left upper back pain, diarrhea, weight loss, and general weakness. We prescribed him Banchongsangamibang (蟠蔥散加味方). For about 1 year, he was treated with oriental medicine. All of his pancreatic pseudocysts disappeared on abdominal CT follow-up and the symptoms mostly subsided. There had been no recurrence of pancreatic pseudocysts on abdominal CT follow-up after 1 year.

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부하 추종형 실시간 변압기 손실감소운전시스템 개발과 시범운영 경제성 분석 (The Development of an Operating System for Load-following Real-time Transformer Loss Minimization and Economic Analyses on its' Test Operation)

  • 이옥배;안재경
    • 전기학회논문지
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    • 제61권6호
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    • pp.797-803
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    • 2012
  • In this paper, for minimizing the real-time operating load losses of the power transformer, a SCADA optimum operating system was developed, and the economic analyses on the test operation were performed. Transformer loss DB which reflects the economic integration operation criteria was constructed by referring the transformer manufacturer's loss data(iron loss, copper loss). Based on the loss DB, each substation transformer real-time loss was calculated according to the size of the transformer loads, and if integration or separation transformer operating conditions minimizing the loss are met, then a window pops-up and the dispatcher performs the substation equipments operation according to the procedure provided by this system. With the existing SCADA main program, the relation database of the substation facilities and integration/separation operation algorithm were developed and applied to Auto MTR Processor and pconn Processor Task module. Seven stations test data for seven months were analyzed for the economic analyses, and the results showed that Cost-Benefit ratio was 2.64, and IRR(Internal Rate of Return), 36%, which asserted the economic justification of the proposed system.

Effects of the Low Reynolds Number on the Loss Characteristics in a Transonic Axial Compressor

  • Choi, Min-Suk;Oh, Seong-Hwan;Ko, Han-Young;Baek, Je-Hyun
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년 영문 학술대회
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    • pp.202-212
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    • 2008
  • A three-dimensional computation was conducted to understand effects of the low Reynolds number on the loss characteristics in a transonic axial compressor, Rotor67. As a gas turbine becomes smaller in size and it is operated at high altitude, the operating condition frequently lies at low Reynolds number. It is generally known that wall boundary layers are thickened and a large separation occurs on the blade surface in axial turbomachinery as the Reynolds number decreases. In this study, it was found that the large viscosity did not affect on the bow shock at the leading edge but significantly did on the location and the intensity of the passage shock. The passage shock moved upstream towards leading edge and its intensity decreased at the low Reynolds number. This change had large effects on the performance as well as the internal flows such as the pressure distribution on the blade surface, tip leakage flow and separation. The total pressure rise and the adiabatic efficiency decreased about 3% individually at the same normalized mass flow rate at the low Reynolds number. In order to analyze this performance drop caused by the low Reynolds number, the total pressure loss was scrutinized through major loss categories such as profile loss, tip leakage loss, endwall loss and shock loss.

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혼류 펌프의 성능 해석 (Performance prediction of mixed-flow pumps)

  • 오형우;윤의수;정명균;하진수
    • 대한기계학회논문집B
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    • 제22권1호
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    • pp.70-78
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    • 1998
  • The present study has tested semi-empirical loss models for a reliable performance prediction of mixed-flow pumps with four different specific speeds. In order to improve the predictive capabilities, this paper recommends a new internal loss model and a modified parasitic loss model. The prediction method presented here is also compared with that based on two-dimensional cascade theory. Predicted performance curves by the proposed set of loss models agree fairly well with experimental data for a variety of mixed-flow pumps in the normal operating range, but further studies considering 'droop-like' head performance characteristic due to flow reversal in mixed-flow impellers at low flow range near shut-off head are needed.

지방의료원의 흑.적자 구분별 경영성과요인 (Major Factors Influencing on the Financial Performance of Local Government Hospitals)

  • 이창은
    • 보건의료산업학회지
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    • 제4권1호
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    • pp.99-110
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    • 2010
  • The purpose of this study is to analyze the internal factors that influence the performance of local government hospitals in Korea. Out of 34 Local Government hospitals, 6 hospitals were selected as sample hospitals. Then hospitals were divided into two groups(3 hospitals each), one of which was profit-making and the other loss-making. The criteria in selecting profit or loss-making hospitals was Normal Profit to Total Assets. The major findings of this study were as follows : The headcount per 100 bed of the profit-making hospitals was 8.8 persons less than the loss-making hospitals and the ratio of payroll expenses to total revenue 14.7% less. Inpatient bed occupancy ratio of the profit-making hospitals was 92.8%. This result is higher 21.8% than loss-making hospitals.

감각신경성 난청의 예후 인자에 대한 평가와 침구 치료에 대한 임상적 고찰 (The Assessments of Prognotic Factors on Sensorineural Hearing Loss And The Clinical Study with Acupuncture Treatment)

  • 문경숙;이소열;권오섭;장조웅;권혁성;윤대환
    • Korean Journal of Acupuncture
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    • 제23권4호
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    • pp.101-110
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    • 2006
  • Objectives : The purpose of this study was clinical observation about sensorineural hearing loss compare with acupucture treatment and assessments of prognotic factors. Methods : This study was clinical observation about sensorineural hearing loss cases. for diagnosing in these cases, pure tone audiometry was used. The treatment, acupuncture was used. Results : Three patients(37.5%) remarkably improved, one patient(12.5%), slightly improved, four patients(50%), no change. Conclusions : These results suggest that the prognosis by age and initial hearing threshold was significant. The treatment on sensorineural hearing loss considered that bone condution improved.

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발전기 계자보호를 위한 계자상실 알고리즘에 관한 연구 (A Study on Loss of Excitation Algorithm for Generator Field Protection)

  • 박유영;박철원
    • 전기학회논문지P
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    • 제63권4호
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    • pp.368-372
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    • 2014
  • The most widely used scheme for detecting loss of excitation on generator is used to sense apparent impedance from generator terminals. This paper presents loss of excitation algorithm using DFT filter based negative offset mho elements for generator field protection. It's algorithm includes two negative mho characteristics looking in the generator. The generator control system was modeled by PSCAD/EMTDC software, and then the proposed algorithm was tested by the collecting relaying signals from selected the generator model. From simulation results, the loss of excitation algorithm can be used to field protection for generator.