• 한국수학교육학회지시리즈C:초등수학교육
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• 제3권1호
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• pp.79-88
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• 1999

This paper shows how the social tradition and belief of korea on education affects teachers and students and learning. 1 Interview with teacher. During surveying this teacher's class, we knowed that the teacher have accentuated algorism loaming and preparation fur external examination in math class. Teacher's beliefs about mathematics have a strong effect on the method of class and the performance of problem solving 2. Interview with students and short test. 1) Students usually had fine ability of calculation for number. But Many pupils didn't know the meaning of the operations. 2) The most of pupils are good at routine math problem solving but when the question whose the condition don't meet was given, they experienced difficulties.3.Korean sociocultural specialty on education: The korean place high emphasis on education and think of education as the means of success. This emphasis can be traced to the Confucian view. 1) tradition on examination culture. 2) the traditional convention of the learning method. Korean sociocultural specialty on education play role of strengthen role learning and algorism class. The important things to education reformation are getting a balance between practice and understanding. we should make changes not only in national dimension but also in math class.

• 산업공학
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• 제24권1호
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• pp.8-14
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• 2011

Principal Component Analysis (PCA) reduces the dimensionality of the process by creating a new set of variables, Principal components (PCs), which attempt to reflect the true underlying process dimension. However, for highly nonlinear processes, this form of monitoring may not be efficient since the process dimensionality can't be represented by a small number of PCs. Examples include the process of semiconductors, pharmaceuticals and chemicals. Nonlinear correlated process variables can be reduced to a set of nonlinear principal components, through the application of Kernel Principal Component Analysis (KPCA). Support Vector Data Description (SVDD) which has roots in a supervised learning theory is a training algorithm based on structural risk minimization. Its control limit does not depend on the distribution, but adapts to the real data. So, in this paper proposes a non-linear process monitoring technique based on supervised learning methods and KPCA. Through simulated examples, it has been shown that the proposed monitoring chart is more effective than $T^2$ chart for nonlinear processes.

• 한국항해학회지
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• 제24권4호
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• pp.269-283
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• 2000

Service is the source of firm's competitive advantage in recent years. The importance of service quality in any service industry doesn't need to be disputed. Customers have expected the improvement of the quality of service they receive ,so providers are struggling to meet these expectations. This study aims at finding factors of service quality in passenger transportation. An empirical investigation and the measurement on the perceived Service Quality by customers in the passenger transportation system was carried out. The purpose of this study is to clarify the factors of service quality on the basis of service marketing concept. In order to fulfill the objectives, this paper combines research tools that include both empirical study and documentary research. Data was gathered from 239 passengers by the use of questionnaire. In this study, the established hypotheses were generated on the basis of the service quality evaluation (SERVQUAL) model. Research findings through empirical test are as follows. First, five service quality dimensions in passenger transportation are identical to SERVQUAL dimensions defined by Parasuraman, Zeithaml, and Berry in 1988. Second, demographic segments such as gender and age don't have significant different dimension of service quality. Third, there is no significant difference between groups by experiences such as price level, abroad tour and vehicle type in determinants of transportation service quality.

• 폴리머
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• 제28권3호
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• pp.263-272
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• 2004

자동차 계기판을 제조하는 기체 사출 성형의 공정에 있어서 전산 모사를 통한 공정성 및 제조된 제품의 물성 향상에 관한 연구를 수행하였다. ABS 삼원공중합체의 P-V-T 자료를 이용하여 기체 사출 공정을 적용하였으며 시간에 따른 금형 충전 효과를 예측하였다. 또한 기체 사출 성형에 있어서 압력, 충전 시간, 기체의 주입 통로 및 런너의 위치 등 다양한 가공 인자들을 변화시킴으로서 공정의 최적 조건을 찾을 수 있었다. 이러한 전산 모사를 통하여 확립된 공정을 통해 제조된 계기판은 일반적인 사출 성형법에 의해 제조되어진 제품에 비해서 우수한 치수 및 변형 안정성이 개선되었다.

• 한국임상수의학회지
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• 제32권4호
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• pp.330-333
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• 2015

1년령 intact male mixed dog(체중 20 kg)가 복부 팽창과 심각한 운동불내성을 주증으로 내원하였다. 심전도 검사에서 심방정지와 함께 두드러진 서맥(46-79회/분)이 관찰되었다. 실험실 검사상 특별한 이상 소견은 관찰되지 않았다. 혈청 cortisol과 T4농도는 정상 범위였다. 영상검사상 심장비대, 복수, 모든 심장 chamber의 확장, 심방정지, transmitral A-peak 소실, 이첨판과 삼첨판 역류, 정상 좌심실 수축기 직경이 관찰되었다. 검사결과에 근거하여 특발성 심방정지로 진단되었으며 심부전에 준한 일반적인 치료를 실시하였다.

• 한국추진공학회지
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• 제2권1호
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• pp.59-66
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• 1998

고체 추진제 연소불안정에 관한 해석은 준-정상 1차원 해석인 QSHOD(Quasi-Steady Homo-geneous One-Dimension)에 의하여 단순화된 지배방정식을 이용하여 응축영역을 해석하는 것이 일반적이다. 이때 외부교란에 대한 기체영역과 표면반응 영역의 응답은 화학반응이 발생하지 않는 고체영역의 응답에 비하여 매우 빠르므로 준-정상적인 거동을 한다. 본 연구에서는 복사열전달에 의한 열속(heat flux)이 고체 추진제의 표면에 존재하며 이 중의 일부가 고체영역으로 흡수될 때 표면에서의 선형교란을 고려한 ZN(Zeldovich-Novozhilov) 방법을 이용하여 연소불안정 현상을 이론적으로 해석하여 연소불안정 현상을 설명할 수 있는 연소 응답함수를 구하였다. 응답함수는 T-burner의 실험결과를 예측할 수 있음을 보여주었다.

• 한국압력기기공학회 논문집
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• 제18권2호
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• pp.77-86
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• 2022

This study investigates the effect of the diameter and thickness on crack initiation location and orientation of 90° elbows under in-plane mode displacement-controlled cyclic bending loads. Finite element (FE) analysis of cyclic failure test is conducted for elbow specimens under in-plane mode displacement-controlled cyclic bending to identify the parameters affecting crack location and orientation. Furthermore, parametric FE analysis of the pipe elbows with various pipe nominal sizes and Schedules is performed, and the crack location and orientation from the results of FE analysis are determined. It is found that the crack location and orientation in the pipe elbows are determined mianly by the radius to thickness ratio of pipe elbows (R_m/t). It is also found that the presence of internal pressure slightly increases the value of R_m/t at which the failure mode changes.

• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.102-106
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• 2005

Objective : The purposes of this study are to evaluate the efficacy of en bloc open-door laminoplasty and to investigate the validity of various factors as prognotic indicators in patients with multisegmental spondylotic myelopathy and ossification of posterior longitudinal ligament[OPLL]. Methods : The authors reviewed 43 cases in whom laminoplasty were performed for cervical myelopathy between January 2000 and December 2002. Clinical symptoms and results were evaluated using the Japanese Orthopaedic Association[JOA] scale. The recovery rate was calculated and then assessed for prognostic factors such as preoperative JOA scores, ages, history of previous trauma, duration of symptoms and signal change in cord on T2-weighted magnetic resonance Image. Results : In cervical stenosis, canal widening of antero-posterior diameter and dimension after laminoplasty is 4.16mm, $87.43mm^2$ and in OPLL is 6.20mm, $117.61mm^2$. In all cases there wasn't neurologic deterioration, mild postoperative complications developed in seven cases. Four patient had a limitation of range of neck motion and the other one showed kyphotic change and another two showed C5 radiculopathy. The recovery rate of JOA score in cervical stenosis and OPLL was 62% and 68% respectively. Duration of symptoms, the severity[preoperative JOA score], and signal change in cord on T2-weighted magnetic resonance image had close relationship to the clinical outcomes. Conclusion : Unilateral en bloc laminoplasty is simultaneous expansile and decompressive method. And preoperative JOA score, symptom duration and high signal intensity on T2-weighted magnetic resonance image can be used to predict prognosis.

• 대한기계학회논문집
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• 제16권9호
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• pp.1605-1614
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• 1992

본 연구에서는 고장력 7075-T73 알루미늄합금에 대하여 변동하중의 기보파형 인 단일과대하중과 고-저(high-low) 블럭하중하의 지연거동에 미치는 과대하중비 %O.L., 기준응력확대계수범위 .DELTA. $K_{b}$ 및 무차원 균열깊이 a/W의 영향을 규명하였 으며, 또한 Wheeler모델의 수정에 의한 예측피로수명을 실험치와 함께 검토하였다.다.

• 대한후두음성언어의학회지
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• 제8권2호
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• pp.217-224
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• 1997

The present study was performed to investigate the voice onset time(VOT) of Korean stop consonants as the expanded research of Pyo and Choi(1996) : the intensity, and the air flow rate of Korean stops as the preliminary study f3r the classical singing training. Nine Korean stops(/P, P', $P^{h}$/, /t, t', $t^{h}$/, /k, k', $k^{h}$/) and a vowel /a/ were used as speech materials. CV and VCV syllable patterns were used for VOT measurement, and CV pattern was used for intensity and air flow rate measurement. Five males and five females pronounced the speech tasks with comfortable pitch and intensity : VOT, intensity, and air flow rate were measured. As results, the prevocalic stop consonants showed bilabials, the shortest VOT and velars, the longest one, except the unaspirated stops which showed the shortest was velar /k'/, and the alveolar /t'/ was the longest. Considering the tensity, heavily aspirated stops showed the longest, and the unaspirated, the shortest. Also the intervocalic stops showed similar results with the prevocalic stops, except the slightly aspirated stops which showed alveolar sound was the longest, and the bilabials, which showed the shortest was the slightly aspirated /p/, unlike the prevocalic stops, the unaspirated /p'/ the shortest. All of prevocalic stops showed the highest air flow rate in heavily aspirated stops, the second, thee slightly aspirated ones, and the lowest was the unaspirated stops. And as a whole, bilabials were the highest, and velars, the lowest, except in the heavily aspirated stops, which was the alveolar sound, the lowest. In the dimension of intensity, the unaspirated and bilabials were the highest, and the heavily aspirated and velars were e lowest, except the slightly aspirated stops, which were the bilabials the lowest, and the alveolars the highest.