A Production Plannong Model under JIT Delivery Centracts

Kim, Keun-Chong 홍익대학교 산업기술연구소 2000 産業技術 Vol.10 No.-

We have considered JIT delivery companies who have to decide how much to produce in a period under nonhomogeneous demands of their products. Duenyas et al.^6) studied this case and found a solution under homogeneous random demands. Wang and Gerchak^15) investigated a production planning problem in a periodic review environment with variable production capacity, random yields, and uncertain but stationary demand. Morton and Pentico^12) derived several upper bounds and a lower bound for a nonstationary stochastic periodic review inventory problems with proportional costs. Kim^9) extended their results to the direction of variable production capacity, random yields, and nonstationary demand case. Using their results to our case, we can derive several upper bounds and an analogous lower bound for nonhomogeneous random demand case instead of nonstationary one for JIT delivery companies.

Myopic Bounds for the Random Yield and Nonstationary Stochastic Leadtime Demand Problem

Kim, Keun-Chong,Song, Young-Hyo The Institute of Management Hong-ik University 2001 Hongik business review Vol.4 No.-

The purpose of the current paper is to combine the results of Morton and Pentico^3) Anupindi et al.^4) for the nonstationary stochastic leadtime inventory problem with recent works of Kim^12,13) which considered the production capacity, random yields, and nonstationary demand, and a production planning model under JIT delivery contracts. We can obtain myopic, and near-myopic heuristic upper and lower bounds for the case of nonstationary stochastic leadtime demands with random yields due to the variable production capacity.

성장기 아동의 single tooth scissors bite의 교정 치료: 증례 보고

김지인,현홍근,김영재,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2011 大韓小兒齒科學會誌 Vol.38 No.4

A scissors bite in the posterior teeth occurs when the upper teeth are positioned totally buccal to the lower teeth in centric occlusion, either unilaterally or bilaterally. This malocclusion can result from either excessive width of the maxilla or deficient width of the mandible, or sometimes combination of the both. Scissors bite, when left untreated without a proper dental intervention, interferes with the normal mandibular growth leading to a state where consequent disharmony in dental arch width evokes occlusal disturbances. Therefore, early preventive orthodontic treatment is necessary in patients with scissors bite. Scissors bite rarely involves anterior and posterior sites concuttently across the dental arch but usually affect single tooth. Even in the single tooth scissors bite cases, more likely to be met in the clinical fields, immediate dental intervention is indicated because continuous occlusal forces that exacerbate the already adverse axis of the posterior teeth. In this case study, patients with single tooth scissors bite, each 7, 14, 12, and 16 years old, were each treated with criss-cross elastic, fixed appliance, removable appliance, and miniscrews. With the proper selection of appliances appropriate to each specific cases, good treatment outcome can be achieved without resulting any side effects. 중심교합위의 상태에서 편측 혹은 양측으로 상악 구치부의 치아가 하악 구치부의 협측으로 위치한 경우를 scissors bite라 고 한다. 이는 상악의 폭경이 크거나 하악의 폭경이 좁은 경우 발생한다. Scissors bite의 경우 방치하게 되면 하악의 성장이 방해받게 되고 그 결과, 악궁 폭경의 부조화가 심해져 저작 장애를 일으킬 수 있으므로 조기 차단 교정이 반드시 필요하다. 실제 임상에서는 여러 치아의 scissors bite보다 최후방 구치 혹은 그 외 하나의 구치만의 single tooth scissors bite(STSB)을 보이는 경우가 많다. 이러한 STSB의 경우도 방치하게 되면 저작력으로 인하여 구치의 각도가 더욱 악화되므로 즉각적인 치료가 필요하다. 본 증례에서는 STSB를 보이는 7세, 14세, 12세, 16세의 환자에게 각각 criss-cross elastic, 고정성 장치, 가철성 장치, miniscrew를 사용하여 치료한 증례를 보고하였다. 각 환자의 증례에 적합한 장치를 잘 선택하여 사용한다면 치아를 정출시키는 등의 부작용을 야기하지 않고 양호한 결과를 얻을 수 있을 것이다

상악 제2유구치와 상악 제1대구치의 치관 형태: 치아계측학적 연구

김지인,현홍근,김영재,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2011 大韓小兒齒科學會誌 Vol.38 No.4

The basic structure of the primary crowns usually resemble their succeeding permanent teeth. However, maxillary second primary molars resemble ipsilateral first permanent molars. Accordingly in this study, odontometric data of the two teeth was obtained, then analyzed to verify the morphological relationship and sex difference between the two teeth. Dental study casts were examined for their mesiodistal and buccolingual width of the crowns, diameter of each cusps, and intercuspal distances. Photographs of the crowns were taken to measure the angles between each cusp tip. The results are as follows : 1. In boys, PrI, PaI, DBC angle, and MBC angle did not show any statistically significant difference between the two teeth(p>0.05), and moderate level of correlations were observed. 2. In girls, crown index, DBC angle, and MBC angle of the two teeth did not show any statistically significant difference(p>0.05), and moderate level of correlations were recognized. 3. Measurements that did not show statistically significant difference between the two teeth in both boys and girls were DBC angle and MBC angle(p>0.05). In DLC angle, however, statistically significant difference was observed(p<0.01). 4. Most of the measurements showed sex differences, except DBC angle, which did not show any sex difference in both teeth(p>0.05). 유치 치관의 기본적인 구조는 대개 계승 영구치를 닮는다. 그러나 제2유구치는 계승 영구치인 제2소구치보다 오히려 제1대 구치와 더 유사한 경향이 있다. 이에 본 연구는 한국인에서 상악 제2유구치와 제1대구치의 치아계측학적 자료(odontometric data)를 얻어 두 치아의 형태와 크기 사이의 연관성을 살펴보고, 나아가 남녀간의 차이점 유무를 고찰해 보고자 하였다. 남아 150명, 여아 150명 총 300명의 모형을 이용하여 상악 제2유구치와 상악 제1대구치의 근원심 치관 폭경, 협설측 치관 폭경, 각 교두의 직경, 교두정간 거리를 계측하였고, 치관의 교합면 사진을 촬영하여 각 교두정 사이의 각도를 측정하여 다음과 같은 결과를 얻었다. 1. 남아에서 Protocone index, Paraconeindex, Distobuccal cusp(DBC)각, Mesiobuccal cusp(MBC)각은 상악 제1대 구치와 제2유구치 사이에 통계적 유의차가 관찰되지 않았고(p>0.05), 중등도의 상관관계가 확인되었다. 2. 여아에서 crown index, Distobuccal cusp(DBC)각, Mesiobuccal cusp(MBC)각은 상악 제1대구치와 제2유구치 사 이에 통계적 유의차가 관찰되지 않았고(p>0.05), 중등도의 상관관계가 확인되었다. 3. 남, 여 모두에서 Distobuccal cusp(DBC)각, Mesiobuccal cusp(MBC)각은 두 치아 사이에 유의할만한 차이를 보이 지 않았고(p>0.05), Distolingual cusp(DLC)각에서는 통계적 유의차가 관찰되었다(p<0.01). 4. 대부분의 계측치에서 남녀 차이를 나타냈지만, Distobuccal cusp (DBC)각은 상악 제1대구치와 제2유구치 모두에서 남녀 차이를 보이지 않았다(p>0.05).

3상 농형유도기를 사용한 자여식 단상유도발전기의 속도특성

김재민,홍문석,진충민,좌종근 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.2

The speed characteristics of self-excited single-phase induction Generator using Three-Phase Squirrel-Case Induction Machine which has only two series capacitors with respect to the load are analyzed in this paper. The symmetrical component method and the condition of equivalent circuit are applied to develop an equivalent model of this generator. The speed characteristics of this generator are computed by using this model and compared with those of the self-regulated generator.

스타인메츠결선에서 커패시턴스의 결정

김도진,좌종근 제주대학교 공과대학 첨단기술연구소 2006 尖端技術硏究所論文集 Vol.17 No.2

This paper investigates methods of determining suitable capacitors which are used in Steinmetz connection. The capacitances of capacitors are determined throughout the slip range using the condition of i )Minimum voltage unbalance, ii) minimum negative sequence voltage, or iii) zero voltage unbalance factor. The torque and efficiency characteristics are depicted by applying these capacitances and compared one another in order to choose suitable method.

불평형 전압이 인가된 유도전동기 동손의 예측

김도진,좌종근 제주대학교 공과대학 첨단기술연구소 2004 尖端技術硏究所論文集 Vol.15 No.2

This paper describes the method of predicting copper loss of an induction motor which is operated by unbalanced voltage, with minimun operation data. The unbalanced current and speed of motor are needed for these data. The current unbalance factor(CUF), symmetrical components of current, and CUF angle are computed by using the definition of symmetrical coordinate method. The equivalent circuit parameters under operating condition are determined using the ratio of symmetrical component of voltage and current, and symmetrical impedances. The copper loss is reasonably predicted by these parameters.

단상전원에 접속된 3상유도전동기의 운전특성분석(I)

김도진,좌종근 제주대학교 공과대학 첨단기술연구소 2006 尖端技術硏究所論文集 Vol.17 No.1

This paper analyzes the operating performance of three-phase wye connected induction motor which is connected to a single-phase source. Symmetrical component theory is used to derive the performance equations of the motor with a single capacitor as the static phase converter. The condition for cancelling negative sequence component of the stator terminal voltage is used to find capacitance of the capacitor. Using this capacitor, the performance characteristics in the whole slip range are computed and analyzed.

二母數 옵션 價格 變動性 實證 分析

金槿鐘 홍익대학교 산업기술연구소 1997 産業技術 Vol.7 No.-

There have been many empirical reports that market option prices and theoretical ones have discrepancies. Except the constant elasticity of variance model of Cox, all theoretical models used a one-parameter diffusion coefficient. A two-parameter function has been adopted to see whether we can have a better theoretical model. A regular and a weighted nonlinear least squares methods have been developed. And a numerical method with a finite difference technique is used. The exercise price biases can be reduced substantially.

二母數 先物옵션 價格 變動性 實證 分析

金槿鍾 홍익대학교 산업기술연구소 1998 産業技術 Vol.8 No.-

There have been many empirical reports that market option prices and theoretical one have discrepancies. Except the constant elasticity of variance model of Cox, all theoretical model used a one-parameter diffusion coefficient. A two-parameter function has been adopted to see whether we can have a better theoretical model. A regular and a weighted nonlinear least squares methods have been developed. And a numerical method with a finite difference technique is used. The exercise price biases can be reduced substantially. And to our surprise, parameters of the gold futures options are relatively stable than that of equity options.