• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1224-1227
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• 2009

When evaluating the quality of images and displays, it is important to combine the characteristics as perceived by the human visual system and measured by equipment using subjective and objective methods, respectively. In the case of objective methods, the quality of a display is measured using colorimetric or radiometric devices according to existing standards covering the color temperature, gamut size, gamma characteristic, and device characterization. Meanwhile, subjective methods assess the quality of an image using the human visual system based on a comparison with a reference or counterpart using such metrics as the sharpness, noise, contrast, saturation, and color accuracy. Objective and subjective methods are usually used together in comparison, as ultimately it is observers watching images on a display. In addition to existing objective methods, a new image quality metric is also introduced as regards the JPEG compression ratio that is reflected in the relationship between the gamut size and the color fidelity in CIELAB color space.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권7_8호
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• pp.618-641
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• 2003

소프트웨어 제품의 품질을 평가하기 위한 방법으로써 품질 요소, 품질 항목 및 여러 가지 메트릭을 이용한 품질 모델들이 제시되어 왔다. 하지만, 소프트웨어의 품질을 보다 정확하게 평가하기 위해서는 각각의 특징에 맞는 특화된 모델이 필요하다. 본 논문에서는 소프트웨어 컴포넌트 개발에 있어서 개발이 진행중인 상태의 소프트웨어 내부 속성에 적절한 메트릭을 적용시킨 결과를 이용하여 개발 완료 후의 소프트웨어가 가지게 되는 외부 품질을 어떻게 추정하는지에 대한 외부 품질 추정 모델을 제시한다. 소프트웨어 품질을 측정하기 위한 메트릭을 적용한 결과로써 품질 자체를 측정하는데 한정하지 않고, ISO 9126에서 제시하는 소프트웨어의 내부 속성을 이용하여 소프트웨어 컴포넌트 개발의 각 산출물에 어떻게 적용시키는지에 대한 모델을 예제를 통하여 제시한다.

• 품질경영학회지
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• 제47권3호
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• pp.479-496
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• 2019

Purpose: The purpose of this research is to develop defense quality evaluation model in order to improve the problem of private sector quality evaluation model and propose the total integrated defense quality management model which enables to evaluate not only large defense industry, but also small-medium industry. Methods: This paper consider the characteristics on ISO 9001 Quality Management System, single PPM, PASS and defense quality and develop defense quality maturity model and index which enables to measure the current quality management level and characteristics and to evaluate operational characteristics in each maturity level for domestic defense industry. Results: From 176 DQMS certified defense industry, the defense quality maturity level is 68,2, C grade. The large defense industry shows, 80.9, A grade; medium industry 69.7, C grade; small-medium industry shows 54.1, D grade. Through the classified types of industries, the current level of quality management of defense industries was diagnosed and the areas to be supplemented for the total quality management were identified. Conclusion: Developed DQMI can be used as the basic information for spreading quality management activities in the defense industry by diagnosing the overall quality management of existing defense industries and quantifying the ambiguity of non-metric measurements and measurement standard that were presented as the threshold of the defense quality management system certification process.

• 대한전자공학회논문지SP
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• 제45권2호
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• pp.21-28
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• 2008

본 논문에서는 비디오 화질 평가를 위해 움직임 벡터의 1차원 히스토그램을 비디오의 특징으로 이용하는 새로운 reduced-reference (RR) 평가 방법을 제안하였다. 제안한 화질 평가 방법은 수신단에서 열화 비디오를 재구성하는 대신 비디오 스트림 (video stream)의 파싱 (parsing) 과정에서 움직임 벡터를 직접 얻을 수 있기 때문에 수행시간 면에서 기존의 방법들에 비해 효율적이다. 또한 송신단에서는 입력 비디오 영상 전체에 대해 누적된 움직임 벡터의 1차원 히스토그램을 보내기 때문에 데이터량 측면에서도 효율적이다. 여기서, 기존의 방법들이 영상 한 장씩에 대해서 평가를 했던 것과 달리 제안한 방법에서는 전체 영상에 대해 누적된 움직임 벡터의 1차원 히스토그램을 사용하였다. 히스토그램의 유사도를 측정하기 위해 히스토그램 인터섹션 (histogram intersection)과 히스토그램 파이 (histogram difference)을 사용하였다. 여러 가지 비트율 (bit rate), 영상크기, 프레임율 (frame rate)로 코딩된 비디오 클립 52개에 대해 제안한 방법과 기존의 방법들을 비교하였고, 제안한 방법의 효율성을 기존 방법들과의 비교 실험을 통해 보였으며, 실험 결과를 통해, 제안한 방법이 기존의 방법들보다 mean opinion score (MOS)와 유사함을 보였다.

• 환경생물
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• 제37권1호
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• pp.8-18
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• 2019

본 연구에서는 만경강 본류에서 2009~2016년 동안 어류의 트로픽 길드, 오염도, 내성도 및 어류평가지수(Fish Assessment Index; FAI)에 기반을 둔 다변수 생태건강도에 대한 화학적 수질 영향을 분석하였다. 수질 지표로서 전기전도도, 총인(TP) 및 암모니아성 질소($NH_4-N$) 농도는 최하류지점에서 가장 악화되는 것으로 나타났다. 어류현장 조사 결과, 8년간 만경강 본류에서는 총 14과 50종이 채집되었으며, 우점종은 내성종으로 잘 알려진 피라미(Zacco platypus)로서 22.9%를 차지하여 트로픽 특성의 악화현상을 보였고, 최류역에서는 비정상어종의 상대빈도가 가장 높게 나타나 생태교란이 아주 심각한 것으로 나타났다. Pearson 상관도 분석에 따르면, 내성어종 및 잡식어종의 상대빈도는 전기전도도, BOD 및 $NH_4-N$와 통계적으로 유의한 상관관계(r>0.30, p<0.05)를 보였고, 민감어종 및 충식어종의 상대빈도는 이들 변수들과 유의한 역상관 관계(r<-0.3, p<0.01)를 보였다. 어류 다변수 모델(FAI)을 이용한 생태건강도로서 평가된 FAI 모델 값은 평균 47(n=40)로서 건강도는 "보통상태(C)"로서 나타났고, 하류역(S3~S5) 지역에서 모델값은 모두 "나쁜상태(D)"로 나타나 수질악화에 의한 영향으로 평가되었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.186-189
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• 2005

Since human listening is very sensitive to sound, a subjective index of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. Many researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. In this study a reliable index is constructed and analyzed using correlation analysis, regression analysis and weighting factor for each sound quality factor. We have made the sound quality index that agrees with more than human subjective sensitivity which apply to various sound quality metrics. Also we applied a 'grade' metric to jury for sound evaluation, analyzed relation between sound duality index and sound quality grade. Then we will judge the sound quality level according to the sound quality grade scheme.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.137-140
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• 2007

A prediction model for the sound quality of household refrigerator noise was proposed by investigating subjective and objective attributes of the noise [Jeon et al. (2007) Appl. Acoust.]. In the present study, the just noticeable difference (JND) of each sound quality metric - Zwicker's loudness, sharpness, roughness and fluctuation strength - which constitute the prediction model was investigated. Loudness of recorded sound samples from five refrigerators were varied according to constant intervals in sound pressure levels. Sharpness was also changed at 14-16 barks. Auditory experiments were conducted to discriminate the JNDs of loudness and sharpness by method of limit. The results indicated that JNDs of loudness and sharpness were 0.50 sone and 0.08 acum, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권10호
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• pp.4886-4907
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• 2019

The use of mobile devices is increasing in multimedia applications. The multimedia contents are delivered to mobile users over heterogeneous networks. Due to fluctuation in bandwidth and user mobility, the service providers are facing difficulties in providing Quality of Service (QoS) guaranteed delivery for multimedia applications. Multimedia applications depend on QoS parameters such as delay, bandwidth, and jitter to offer better user experience. The existing schemes use the single source and multisource delivery but are unable to balance between stream quality and network congestion for mobile users. We proposed a Quality Oriented Multimedia Content Delivery Scheme (QOMCDS) for the mobile cloud to deliver better quality multimedia contents for the mobile user. The multimedia contents are delivered to the mobile device based on the device's parameters and network environment. The objective video quality assessment models like Peak Signal-to-Noise Ratio (PSNR), Structural Similarity (SSIM), and Video Quality Measurement (VQM) are used to measure the quality of the video. The client side Quality of Experience metric such as Startup delay, Rebuffering events, and Bitrate switch count was used for evaluation. The proposed scheme is evaluated using dash.js and is compared to existing schemes. The results show significant improvement over existing multimedia content delivery schemes.

• 환경영향평가
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• 제21권5호
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• pp.631-648
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• 2012

The integrative ecological approaches of chemical assessments, physical habitat modelling, and multi-metric biological health modelling were applied to Gwanpyeong Stream within Gap-Stream watersheds to evaluate environmental impacts on the constructions of residential and commercial complex. For the analysis, the surveys conducted from 45 sites of reference streams within the Gap-Stream watershed and 3 regular sites during 2009 - 2010. Physical habitat health, based on the habitat model of Qualitative Habitat Evaluation Index(QHEI) declined from the headwaters(good - fair condition) to the downstream(poor condition). Chemical water quality, based turbidity and electric conductivity(EC), was degraded toward to the downstream, and especially showed abrupt increases, compared to the values of control streams(CS). Also, concentrations of chlorophyll-a in the downstreams were greater compared to the control stream(CS), indicating an eutrophication. Biological health conditions, based on the Index of Biological Integrity(IBI) using fish assemblages, averaged 19.3 which is judged as a fair condition by the biological criteria of the Ministry of Environment, Korea. The comparisons of model metric values in sensitive species and riffle-benthic species on the Maximum Species Richness Line(MSRL) of 45 reference streams indicated a massive disturbances in all sampling locations. Also, tolerance guild and trophic guild analyses suggest that dominances of tolerant species and omnivores were evident, indicating a biological degradation by habitat disturbances and organic matter pollutions. There was no distinct longitudinal variations of IBI model values from the headwater to the downstream in spite of slight chemical and habitat health gradients among the sampling sites. Overall, integrative ecological health(IEH) scores, based on the chemical, physical, and biological parameters, were low compared to the 45 reference streams due to physical and chemical disturbances of massive constructions of the residential and commercial complex. This stream, thus showed a tendency of typical urban streams which are disturbed in the chemical water quality, habitat structures, and biological integrity. Effective stream management plans and restoration strategies are required in this urban stream for improving integrative stream health.

• 한국정보과학회논문지:소프트웨어및응용
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• 제26권9호
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• pp.1095-1104
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• 1999

객체지향 시스템의 개발은 클래스를 통해서 이루어진다. 즉, 문제 영역에 존재하는 중요한 대상 또는 개념을 클래스로 모델링하고, 이로부터 생성된 객체들 사이의 메시지 교환을 통해서 시스템은 구축된다. 또한, 클래스는 정보 은닉을 제공함으로써, 객체지향 시스템의 재사용성과 유지보수성에 상당한 기여를 한다. 그러나, 설계 단계에서 실세계의 대상을 부적절하게 모델링하거나, 또는 유지보수 단계에서 클래스에 무분별한 변경을 가하는 경우 클래스의 품질은 악화될 수 있고, 이는 결국 시스템을 유지보수 하거나 확장하는데 상당한 장애를 초래한다.응집도는 모듈의 구성 요소들 사이의 연관성 정도를 나타내는 척도로서 전통적으로 모듈의 품질을 평가하기 위한 기준으로 사용되어 왔다. 이 논문에서는 클래스의 품질을 평가하는 방법으로서의 클래스 응집도를 제안한다. 즉, 클래스가 실세계의 대상을 적절하게 모델링한다면, 그 구성요소들 사이에 밀접한 관련이 있고 결국 높은 응집도를 가지게 될 것이다. 반대로 실세계의 대상에 대한 적절한 모델이 아니라면, 그 클래스의 구성 요소들 사이에는 밀접한 관련성이 없을 것이고 따라서 낮은 응집도를 보일 것이다.Abstract Object-oriented systems are developed by means of classes; that is, classes captures the essential entities or concepts in the problem domain, and the system is embodied by the interactions of objects instantiated from the classes. In addition to the basic units of object-oriented systems, classes serves as the units of encapsulation, which considerably promote the modifiability and the extensibility of them. However, improper modeling in the design phase or uncontrolled changes during the maintenance phase can degrade the quality of classes, which leads to systems cumbersome to maintain and extend.Cohesion refers to the degree of connectivity among the elements of a single module, and is being used as a factor which characterizes the quality of a module. In this paper, we propose a new cohesion metric for assessing the quality of classes. If a class captures properly the essential features of objects, the members of the class surely have strong relationship among them. On the contrary, the poor relationship among class members can indicate that the class is not a proper model of objects.