• 한국소음진동공학회논문집
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• 제20권5호
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• pp.427-436
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• 2010

The printer sound has many aspects which define its quality because the printer has lots of components and its operation is very complicated. These sound qualities are related to the international competition in printer markets. Recordings inside anechoic chamber were analyzed and a large number of sounds were stimulated using digital signal processing technique. First subjective tests of the printer sound were conducted using semantic different method. By applying factor analysis to the subjective response, two important factors of sound quality were extracted. Second subjective tests were conducted to evaluate the quietness and the impulsiveness of the printer sounds. On the other hand, sound metrics are calculated applying psychoacoustic theories. In this paper, the nonlinear relation between subjective evaluation and sound metrics was identified using artificial neural network and the printer sound quality index was developed. Later, subjective sound quality evaluation will be estimated and evaluated using this index.

• 한국광학회지
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• 제5권1호
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• pp.60-66
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• 1994

양영역 불안정형(Positive Branch Unstable) Nd:YAG 레이저 공진기를 모델링하여 공진기내의 TE$M_{00}$ 기본모우드의 waist에 대한 수치해석을 하였으며 이를 토대로 레이저 공진기를 설계 제작하였다. 레이저봉의 열렌즈 초점거리를 측정하였으며 이를 이용하여 빔 waist에서의 TE$M_{00}$ 모우드의 spot size에 대한 계산치와 실험치를 비교하였다. 그리고 고반복률로 발진하는 다중모우드(multimode)의 spot size를 측정하여 beam quality factor $M^2$을 산출하였다. 한편 불안정 공진기에서 얻어진 출력실험 결과를 Plane-Parallel 공진기의 경우에 비교하여 그 특성을 평가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1596-1598
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• 2000

This paper presents the results of lifetime evaluation for porcelain suspension insulator using tensile test. The specimens were collected from the branch offices of the KEPCO. The tensile tests were performed with the instron which had the speed of 1mm per minites. The factors of quality were calculated with the maximum tensile strength measured from each specimens. With the quality factors, a factor of lifetime was determined. The lifetime of porcelain suspension insulator as a factor of fabricated years was evaluated.

• 한국전자통신학회논문지
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• 제18권3호
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• pp.441-448
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• 2023

제조 공정 데이터에 있어 주조 공정은 가장 중요한 공정이면서 높은 불량률의 원인을 발생시키는 공정이다. 주조 공정의 품질관리는 생산성과 품질평가의 핵심 요소라 할 수 있다. 본 연구에서는 공정 데이터를 통한 요인 분석, 상관 분석, 회귀 분석 결과를 기반으로 최적화 된 머신러닝 모델 알고리즘을 개발한다. 이를 적용한 주조공정을 통해서 불량률을 줄이고 스마트 팩토리의 데이터 적합성을 검증하고자 한다.

• 한국콘텐츠학회논문지
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• 제10권8호
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• pp.186-197
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• 2010

최근 재현 장비의 목적은 장면을 정확하게 재현하는 것에서 사용자의 만족도를 높이는 것으로 변화하고 있다. 이는 카메라로 대표되는 재현 장비의 발전 방향이 성능 위주에서 품질 위주로, 개발자 중심에서 사용자 중심으로 전환되고 있다는 의미이다. 따라서 본 논문에서는 사용자의 인지 특성에 기반을 둔 사진의 화질 평가 방법을 제안하고자 한다. 사진은 다양한 물리적 화질 속성이 복합적으로 어우러져 완성되는 것으로 몇 가지 성능에 대한 평가만으로는 전반적인 화질을 평가할 수 없다. 따라서 제 3의 관찰자에 의한 주관적인 화질 평가가 필요하다. 주관적 화질 평가는 평가 방법과 결과 도출 방법이 쉬워야 하고, 도출된 평가 결과는 전체적인 화질을 어우르는 동시에 높은 신뢰도를 가져야 한다. 따라서 본 논문은 화질 만족도에 영향을 미치는 요소들은 분석하여 구체적인 평가 언어를 수립하고, 사진 이미지를 실험 자극으로 활용한 주관적 화질 평가 실험을 통해 화질 평가 항목을 수립함으로써 효율적이고 정확한 방법으로 주관적 화질을 평가할 수 있도록 하였다.

• 한국소음진동공학회논문집
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• 제16권5호
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• pp.551-558
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• 2006

Noise from air-conditioner system installed in the ceiling of a classroom was evaluated to investigate the sound quality of air-conditioning noise. Harmonics of air-conditioning noise were removed and the sound pressure levels of the frequency bands from $250{\sim}630Hz$ were changed to control sound quality. Evaluation for refreshing sensation was conducted using a paired comparison method and the results showed that noise without harmonics were preferred to noise with harmonics. The noises which have larger level increases to the unchanged noise at $250{\sim}630Hz$ were evaluated better in both of the noises with and without harmonics. Results of multiple regression analysis on psychoacoustic parameters and subjective preferences showed sharpness as a major affecting factor in describing the refreshing aspect of air-conditioning sound.

• 품질경영학회지
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• 제49권3호
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• pp.375-392
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• 2021

Purpose: Regional gaps and conflicts between regions due to Korea's economic development and industrialization have become important issues, and the issue of balanced regional development at regional level has been discussed as the size of the region has increased recently. Although evaluation of regional balance was attempted through various regional balanced development indexes, it is inappropriate as a standard for determining regional balance in Seoul. Therefore, this study aims to develop objective evaluation methodologies and evaluation indicators for balanced development of administrative districts in Seoul, not existing city and national units. Methods: We looked at existing regional balanced development indexes, and suggested a new regional balanced index reflecting regional development, backwardness, and spatial characteristics in Seoul using factor analysis. Results: As a result of factor analysis, the regional balanced development index for administrative districts and administrative dongs consists of two factors (regional revitalization, financial power) and three factors (commercial density, social security demand, regional retardness), respectively. Then the regional balanced development index scores for 116 administrative districts and 423 administrative dongs are calculated by multiplying each factor by a weight obtained through experts' survey. Conclusion: The proposed regional balanced development index can be used as an objective and quantitative basis for regional balanced development within a city. Further research may include continuously adding new indicators that reflect the direction and scale of development.

• Journal of Dairy Science and Biotechnology
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• 제14권2호
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• pp.185-193
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• 1996

This study was to investigate principle of freeze concentration such as nucleation, crystal growth and procedure of freeze concentration, essential factor and application of freeze concentration. Especially, quality of milk was emphasized. For exemple, in sensory evaluation of freeze concentrated and reconstituted skim milk and whole milk, taste, color, mouth feel and texture were superior to control. Recently developed technique of freeze concentration for quality milk and dairy products may be expected for advanced quality of various milk and dairy products in near future.

• 한국물환경학회지
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• 제33권6호
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• pp.650-660
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• 2017

In this study, pollutant emission characteristics by water damage period analyzed 11 items (water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and flow) with load duration curve, time series load curve and factor analysis for three years (2014-2016). Load duration curve is applied to judge the level of impaired waterbody and estimate impaired level by pollutants such as BOD and T-P in this study depending on variation of stream flow. Water quality standard exceeded the flow of mid-range and low-range by flow condition evaluation using load duration curve. This watershed was influenced by point source more than non-point source. Cumulative excess rate of BOD and T-P kept water quality standard for all seasons (spring, summer, autumn and winter) except BOD 59% in spring. Water quality changes were influenced by pollutants of basic environmental treatment facilities and agricultural areas during spring and summer. Results of factor analysis were classified commonly first factor (BOD, COD, and TOC) and second factor (flow, water temperature and SS). Therefore, effects of artificial pollutants and maintenance water must be controlled seasonally and reduced relative to water damage caused by point pollution sources with effluent standard strengthened in the target watershed.

• 한국치위생학회지
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• 제11권3호
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• pp.383-393
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• 2011

Objectives : This study has been undertaken for the purpose of finding out what influence is made by the dental care service provided to patients by the dental clinics to the level of patient satisfaction to provide the base data for developing and improving the dental care service of dental hygienist. Methods : The survey was undertaken for 500 patients visiting 18 dental clinics in City G and the questionnaire was undertaken for two weeks in May 2010, and 473 copies were analyzed with the exception of the questionnaires with many omissions in the response. Results : 1. Distribution of the level of satisfaction for patient had the dentist factor which was highest in the dentist factor for 4.43 at the age of 60s (p<0.05). and in sole proprietorship for 4.49 (p<0.01). treatment procedure factor which was highest in sole proprietorship for 4.16 (p<0.001). environment of dental clinic factor which was highest at the age of 60 years or older for 4.36 (p<0.05) and in sole proprietorship for 4.14 (p<0.01). 2. Evaluation on the quality of the dental care service of dental hygienist had the kindness of dental hygienists which was highest at the age of 60 years or older for 4.40(p<0.001), knowledge factor of dental hygienist which was highest for 4.34 at the age of 60 years or older (p<0.05) and highest 4.27 for visit dentists(p<0.001) and the patient management and other factor was highest at the age of 60s for 4.47 (p<0.05), and in sole proprietorship for 4.28 (p<0.05). 3. Factors influencing on the level of satisfaction for patient. The level of satisfaction for patient was higher for higher evaluation of the dentist quality (p<0.001), for feeling convenient in treatment procedure and use (p<0.01), for feeling kindness of the dental hygienist (p<0.01), and for higher evaluation in patient management and other management activities of the dental hygienist (p<0.001). Conclusions : In order to heighten the level of satisfaction for patient, it would be necessary to strengthen the kindness and patient management aspect on the patients of the dental hygienist, and it would require to heighten the quality of dentist as patients recognize and heighten the treatment procedure and service convenience of dental clinics.