• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.500-503
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• 2017

차량 내 전장부품이 증가하고, 차량 OEM(Original Equipment Manufacturing)이 다양한 차종을 생산 판매함에 따라 다양한 SW(software) 형상이 개발되고 있다. 따라서, 기존에 개발된 SW 형상과 변경된 SW 형상 간에 기능 일치성 검증에 대한 필요성이 증가하고 있다. 두 가지 SW 형상 간에 기능 일치성 확인을 위한 테스팅 방법으로 Back-to-Back Testing이 있는데, 이는 각 SW 형상에 동일한 입력값을 주입하고 동일한 출력값이 산출되는 지 확인하는 테스팅 방법이다. Back-to-Back Testing 수행 시 Test case 설계가 필요한데, Test case의 분량과 테스팅 종료기준에 대해서 아직 확립이 되어 있지 않다. 이제 본 논문에서는 MC/DC(Modified Condition/Decision Coverage) 개념을 이용하여 Test case 분량과 테스팅 종료 기준에 대해서 제시하고, 이를 적용한 사례를 설명한다. 본 논문에서 제시한 Test case 설계 기준을 적용하면, 제한적인 테스팅 일정과 인력을 만족하고, 기능 일치를 확인할 수 있는 충분한 테스팅이 가능할 것으로 판단한다.

• 응용통계연구
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• 제22권2호
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• pp.261-270
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• 2009

주식 수익률, 환율 등과 같은 금융 자료를 이해하는데 있어서 최근의 국제 금융위기를 통해 더욱 중요해진 이슈는 바로 변동성(volatility)이다. 변동성(조건부 이분산성)에 대한 모형은 Engle (1982)의 ARCH 모형과 Bollerslev (1986)의 GARCH 모형을 시작으로 수만은 연구가 이루어졌으며 특히 금융 시계열 분석에서는 시계열 자료들 간의 변동성을 함께 모형화 하는 MGARCH(multivariate GARCH) 모형이 널리 이용되고 있다. 추정된 MGARCH 모형들은 그 자체로서 여러 개의 변동성들 간의 시간에 따른 동적인 관계를 설명해주는 데 유용할 뿐만 아니라 추정된 (조건부)상관계수들은 hedge ratio 계산 또는 VaR 계산 등과 같이 금융시장에 대한분석에도 이용되고 있다. 본 논문에서는 국내 14개 최신 주가자료에 대한 MGARCH 분석을 수행하고 연관된 사후검증(back-testing)을 통해 MGARCH 모형들을 평가하고 있으며 사후검증 수치를 얻기 위한 S-PLUS 프로그램을 수록하였다.

• Elastomers and Composites
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• 제2권1호
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• pp.31-36
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• 1967

As a series of the studies of thin rubber coated fabrics, the experiments were concentrated on the investigation of the physical properties of the surface and back coated fabrics with natural and synthetic rubber. Cotton poplin and nine other cotton shootings were used as a base fabric and both sides of fabric, face and back, were coated by means of topping or spreading process. The physical properties of finished material were broadly investigated especially in view of the quality requirements of the poncho.

• 한국전문물리치료학회지
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• 제20권4호
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• pp.22-31
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• 2013

The aim of the present study was to compare measurement precisions of the Oswestry Back Pain Disability Questionnaire (ODQ) and a computer adaptive testing (CAT) method. The ODQ has been regarded as one of the most reliable condition-specific measure for back pain for decades. Cross-sectional study was carried out with two independent convenient samples from two out-patient rehabilitation clinics for back pain ($n_1=42$) and non-back pain group ($n_2=42$). Participants were asked to fill out the ODQ and CAT of International Classification of Functioning, Disability and Health-Activity Measure (ICF-AM). A series of Rasch analyses were performed to calculate person ability measures. The CAT measures had greater relative precision in discriminating the groups than did the ODQ measure in comparisons of the relative precision. The CAT measure appears to be more effective than did the ODQ measure in terms of measurement precision. By administering test items calibrated in a way, CAT measures using item response theory may promise a means with measurement precision as well as efficiency.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.303-310
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• 2000

A new stress path testing scheme with back pressure equalization process is proposed, to compute the settlement of clay soils based on their probable deformation mode. The proposed testing scheme minimizes the efforts for testing, otherwise numerous testing works are required to simulate the probable stress paths in the field. Furthermore, the proposed testing scheme can supply anisotropic stress paths for consolidation which cannot be possible in a conventional way. The validity and effectiveness of the proposed testing scheme was investigated and confirmed with test results on remolded kaolinite clay soils. Conclusively, it is suggested that the proposed testing scheme is a very effective tool to compute settlement of clay soils and it is also very useful to investigate the anisotropic characteristics of deformation of clay soils.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.441-444
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• 2000

This paper covers the performance testing for layer 3 Ethernet switch based on various methodologies by which we can measure essential metrics such as throughput, latency, frame loss rate, and back to back frames. In the first place, layer 2 and layer 3 switch evolution is introduced followed by description of IP packet switching in layer 3 switch. And then, the above test metrics and test methodologies are illustrated as well. At last, we conduct the performance testing for layer 3 switch in case of transmitting packets of 64, 128, 256, 512, 1024, 1280, and 1518 byte size and analyze then results.

• 응용통계연구
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• 제23권2호
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• pp.219-234
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• 2010

시가총액에 따른 인덱스(INDEX) 투자를 했을 경우에, VaR(Value at Risk)을 종합주가지수(KOSPI)로부터 얻은 수익율의 극단 손실값들로부터 추정한다. 이를 위해, 극단값 이론 중 BM(Block Maxima) 모형을 적용하며, 극단 손실값들의 비독립적 발생을 고려하기 위하여, extremal index 역시 추정한다. 모형의 타당성을 알아보기 위해, 실패율방법을 이용한 사후검정 (back-testing) 을 실시한다. 사후검정을 통해, BM 모형을 적용한 VaR의 추정이 적절함을 알 수 있었다. 또한, 일반적으로 많이 사용되는 GARCH 모형을 이용한 VaR의 추정과 비교한다. 이를 통해, 오차가 t-분포를 따른다고 가정하는 경우, GARCH 모형을 이용한 VaR의 추정이 BM 모형을 이용한 경우와 사후 검정결과에 차이가 없음을 확인하였다. 그러나, GARCH 모형을 통한 VaR 추정은 추정시점근방의 극단 손실값들에 민감하게 반응하지만, BM 모형은 그렇지 않았다. 따라서, 현 시점으로부터 단기간동안의 손실위험은 GARCH 모형을 이용한 VaR의 추정값을 사용하는 것이 적절하며, 장기간동안의 손실위험은 BM 모형으로부터 얻은 VaR의 추정값을 사용하는 것이 적절하다.

• 비파괴검사학회지
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• 제22권6호
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• pp.621-626
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• 2002

The amplitude of a back-wall echo depends on the reflection coefficient of the interface between a transducer and a test material when using contact pulse-echo ultrasonic testing. A couplant is used to transmit ultrasonic energy across the interface, but has an influence on the amplitude of the pulse-echo signal. To investigate the couplant effect on pulse-echo ultrasonic testing, back-wall echoes are measured by using various couplants made of water and glycerine in a carbon and austenitic stainless steel specimens. The amplitude of the first back-wall echo and the apparent attenuation coefficient increases with the acoustic impedance of the couplant. The couplant having a higher value of the transmission coefficient is more effective for flaw detection. The reflection coefficient should be known in order to measure the attenuation coefficient of the test material.

• 대한물리의학회지
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• 제5권2호
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• pp.233-243
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• 2010

Purpose : This study aimed to examine the effects of sling exercise therapy on the relief of low back pain and the cross-sectional area change of lumbar muscles by CT analysis for chronic low back pain patients. Methods : Forty-one patients with diagnosis of chronic low back pain was divided sling exercise therapy group(SEG) 19 subjects and conservative physical therapy group(CPG) 22 subjects. we randomized and treated them(subjects) for 12 weeks. As using visual analogue scale(VAS), we evaluated recovery accuracy of pain, and for investigating cross-section area change of lumbar muscles for before and after treatment we used computed tomography(CT). Results : This study were summarized as follows : 1) As treatment period, in each compared testing on VAS of SEG and CPG, the both group was significantly different(p<.05). 2) Compared testing on VAS of between-subject groups(SEG and CPG) were not significantly different(p>.05). 3) At SEG of before and after treatment, in compared testing on cross-section area size of lumbar muscles, All muscles of psoas major, quadratus lumborum, erector spinae and multifidus were significantly different(p<.05). At CPG, psoas major was significantly different(p<.05). But other muscles were not significantly different(p>.05). Conclusion : From this result, both sling exercise therapy and the conservative physical therapy are effect on decrease of pain for chronic low back pain patients. but Increasing of the cross-section area being proportioned with muscular strengthening of low back muscle is noticeable difference in SEG. Therefore, sling exercise therapy have affect both decreasing of pain for chronic low back pain patients and lumbar muscles strengthening.

• Industrial Engineering and Management Systems
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• 제16권1호
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• pp.103-108
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• 2017

Tourism is a sector that plays an important role in the economic growth of Indonesia. Bandung as the capital of West Java province is known as the city with diverse tourism potential, both in the attractiveness of the city and surrounding natural beauty. DHR is a three stars resort hotel in the city with a strategic location. As a three stars resort hotel, DHR has been experiencing occupancy rate problems, consequently, it cannot often reach the set targets, both during high season and low season. The purpose of this study is to identify the factors of hotel performance that influences consumer staying back decision in the future. Questionnaires have been distributed to hotel guests to gather information regarding their interest and the performance assessment of the hotel services and facilities, and staying back decision in the future. Discriminant Analysis and Hypothesis Testing are used to determine which hotel performance variables will directly affect consumer staying back decision. The result of this study provide marketing strategy that should be implemented by the hotel management in order to increase its occupancy rate.