• 한국환경보건학회지
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• 제49권6호
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• pp.295-304
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• 2023

Background: Adolescents are relatively more sensitive than adults to exposure to indoor pollutants. The indoor air quality in classrooms where students spend time together must therefore be managed at a safe level because it can affect the health of students. Objectives: In this study, three types of green-wall models were applied to classrooms where students spend a long time in a limited space, and the resulting effects on reducing PM were evaluated. Methods: In the middle school classrooms which were selected as the experimental subjects, IoT-based indoor air quality monitoring equipment was installed for real-time monitoring. Three types of plant models (passive, active, and active+light) were installed in each classroom to evaluate the effects on improving indoor air quality. Results: The concentration of PM in the classroom is influenced by outdoor air quality, but repeated increases and decreases in concentration were observed due to the influence of students' activities. There was a PM reduction effect by applying the green-wall model. There was a difference in PM reduction efficiency depending on the type of green-wall model, and the reduction efficiency of the active model was higher than the passive model. Conclusions: The active green-wall model can be used as an efficient method of improving indoor air quality. Additionally, more research is needed to increase the efficiency of improving indoor air quality by setting conditions that can stimulate the growth of each type of plant.

• 품질경영학회지
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• 제25권4호
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• pp.99-105
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• 1997

We consider a nonparametric estimation of the renewal function. In this paper, we suggest modified methods for Frees's estimator to enhance the efficiency. The methods are based on a piecewise linearization and on the fact that the bounded monotonic functions converging pointwise to the bounded monotonic continuous function converge uniformly. In a simulation study, we show that the modified methods have the better efficiency than that introduced by Frees.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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• pp.27-31
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• 1998

The growing usage of multimedia communication applications with specific bandwidth and real-time delivery requirements has created the needs for quality of service(QoS). In response to the growing demand for an integrated services, the Reservation Protocol(RSVP) has been designed to exchange resource reservation among routers in the internet. RSVP protocol provides the quality of service for real-time applications but the network efficiency is reduced because of the limited bandwidth. In order to use network resources efficiently. We compare the resource efficiency of traditional reservation methods with that of the proposed method and evaluate the performance of the internet phone.

• KIEAE Journal
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• 제4권3호
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• pp.195-202
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• 2004

This study focuses on the impacts of apartment building arrangements on the outdoor and indoor air quality - the efficiency of natural ventilation in the outside/inside area of an apartment with consideration to the characteristics of an air flow in outside area depending on the types of the arrangements, the main direction of the wind, and the outside wind pressure on the building facade. As indices to evaluate the efficiency of natural ventilation, the concepts of "Age of Air" and "Purging Flow Rate(PFR)" were used in this study. As indices to classify the efficiency of indoor natural ventilation, the mean values of the wind pressure differences between the front and the back elevations of an apartment building were used. The research showed that the PFR of each apartment building arrangement ranges from 0.867 to 3.253. The "minus-shaped" arrangement showed the highest PFR, 2.306; the "zigzag-shaped" arrangement measured 1.889; the "angle-shaped" arrangement measured 1.465, and the "square-shaped" arrangement measured 1.241. Depending on the direction of the wind, the pressure differences range extremely, with variations from 170% to 2300%. Thus, the indoor natural ventilation efficiency can be changed by the pressure differences of the wind, which are sensitive to the main direction of the wind even though the structure and planning of the apartment complexes are the same. Despite the same direction of the wind, even the efficiency can be diverse. This study showed how to predict the most beneficial apartment building arrangement for the profitable natural ventilation efficiency in each direction of the wind.

• 한국생활과학회지
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• 제16권2호
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• pp.349-365
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• 2007

The purpose of this study was to explore the Korean housewives' consumption experiences and perceived quality of life. Perceived quality of life was composed of four dimensions: motivation, affect, efficiency, and activation. The study results are: 1. Housewives spare their time for physiologic activities(22.9%), household activities(20.1), and personal activities(10.1%) in sequence. 2. Although the motivation that housewives do shopping activities is coming from a sense of duty, the perceived quality of life during shopping is showing far more positive affect than the perceived quality of life during other activities. In this context, shopping activities are interesting in that they are thought of a kind of entertainment as well as work. 3. With an analysis of covariance, housewives' perceived quality of life has an effect on everyday life in that 4 perceived qualities of life such as motivation, affect, efficiency and activation has a significant effect on flow and it has a significant effect on satisfaction.

• 대한안전경영과학회지
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• 제7권5호
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• pp.185-212
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• 2005

The ultimate objectives of the six sigma activities are to raise quality of products to the level where customers can be satisfied and to improve marketing efficiency through cost reduction. Recently, many businesses have been struggling to find out the most successful way to implement the six sigma to produce better results. This study is significant in a way that it provides readers with an actual evidence of efficiency and effectiveness of six sigma activities in marketing performance for the first time. The major data of this study can be divided into two categories ; First, secondary data research method was utilized to find out the effects of six sigma management on the quality and marketing performances, theoretically and empirically. Second, test of established hypotheses relevant to the effects of six sigma management on the quality and marketing performance based on the propositions drawn from existing literatures, and test hypotheses statistically. This study of six sigma looked into benefits in manufacturing industry in terms of improving quality, cutting cost and decreasing defection product-defect rate. In addition, the study has verified that how the quality performances can affect the marketing performances, such as enhancing corporate image, sales increase and customer satisfaction. The author believes that this study will help many businesses acquire best methods to increase sales and profits. And, business manager will be able to understand where to focus as they proceed with the six sigma project and improve corporate competitiveness.

• 산업과 과학
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• 1권1호
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• pp.28-34
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• 2022

소프트웨어 품질평가에 대해서는 많은 연구가 진행되어왔다. 최근에 인공지능 관련 소프트웨어들이 많이 개발되어지면서 기존 소프트웨어에 인공지능 기능을 평가하기 위한 방안에 대한 연구가 진행되어지고 있다. 소프트웨어 평가는 기능적합성(Functional suitability), 신뢰성(Reliability), 사용성(Usability), 유지보수성(Maintainability), 효율성(Performance efficiency), 이식성(Portability), 상호운영성(Compatibility), 보안성(Security)이란 8가지 품질 특성을 기반으로 평가 되어왔으나 인공지능 기능을 가지고 있는 소프트웨어의 경우는 8가지 품질 특성뿐만 아니라 인공지능 부분의 기능에 대해서 평가를 통해서 확인해야 하는 부분에 대한 연구가 진행되고 있다. 본 연구는 이 부분에서 평가 방안에 대한 내용을 소개하려 한다. 기존에 소프트웨어 품질 평가 방안과 인공지능 부분에서 고려해야 하는 부분에 대한 제시를 통해서 인공지능 소프트웨어의 품질 평가 방안을 제시하려 한다.

• Asia pacific journal of information systems
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• 제20권2호
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• pp.87-101
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• 2010

Software as a service (SaaS) is one of the most-talked about trends in IT. Unlike traditional perpetual licensing model, software applications are sold on subscription bases and services are provided over web by the vendors. It is said that SaaS can make vendors to invest more on R&D than on marketing while offering its customers better quality software applications at lower costs. By empirically comparing vendors providing their software applications either by SaaS or by traditional perpetual licensing model, we examine whether or not SaaS really increases overall customer benefits in terms of cost efficiency, software quality, and customization. We show that SaaS may not provide better quality or cost efficient software applications than perpetual licensing does. Then we provide two practical tools which are useful for customers to evaluate whether SaaS is better than perpetual licensing for the purposes of software applications they want to adopt.

• 품질경영학회지
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• 제29권4호
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• pp.133-152
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• 2001

In order to have competitive advantage for the business firms, companies need to raise competitiveness through the effective distribution and practical use of management resources along with strategic management of integration of existing management systems such as quality and business environment. Upon resulting of questionnaires to expert group, it is definite to have an integration of quality and environment system for the better efficiency of firms, and also recommended to have either a mixture of two systems or build up new integration system through uniform of two systems. The effects of the integrated system can be summarized as an increase of company image, efficiency of system operation, simplification of system management, synergy effects on the integration.

• 대한전기학회논문지:전력기술부문A
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• 제54권12호
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• pp.561-566
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• 2005

This paper introduces a compression technique for power qualify disturbance signal via discrete wavelet transform(DWT). The proposed approach is based on a previous estimation of the stationary component of power quality disturbance signal, so that it could be subtracted from the original signal in order to reduce a dynamic range of signal and generate transient events signal, which is subsequently applied to the compression technique. The compression techniques is performed through the difference signal decomposition, thresholding of wavelet coefficients, and signal reconstruction. It presents the relation between compression efficiency and threshold. It shouts that the wavelet transform leads to a power quality data compression approach with high compression efficiency, small compression error and good de-nosing effect.