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.

경연 대회를 통한 초ㆍ중고생의 창의력 신장 효과에 관한 연구

이희복,육근철,류해일,김현섭,김희수,박달원,유병환,김선효,김여상,서광수,변두원,서명석,배성효,박종석,심규철,이성희 공주대학교 과학교육연구소 2001 과학교육연구 Vol.32 No.1

미래 사회를 대비하기 위한 개인의 개성을 존중과 창의적인 능력을 지닌 인간을 양성을 목적으로 충청남도 지역의 초 ㆍ 중고등학생들을 대상으로 한 창의력 경연대회가 공주대학교 과학교육연구소에서 개최되었다. 충청남도 초 ㆍ중 ㆍ 고등학생들을 대상으로 실시한 창의력 경연대회는 창조적 아이디어를 내어 스스로 문제를 해결해 나갈 수 있는 교육 프로그램을 제공하는 좋은 기회였음이 확인되었으나, 일부의 팀에서만 참신하고 재미있는 아이디어들이 제안되었다. 여학생의 참가자 수가 상당히 증가하였으며, 대체적으로 입상권의 학생들의 상당 부분이 여학생이라는 것이 특이할만하다. 학년이 올라감에 따라서 창의적인 아이디어를 내는 양이나 질에 있어서 뒤떨어지는 것으로 분석되었으며, 토론 학습의 적응력이 미흡하고 발표력 및 청취력에 있어서도 떨어지는 것으로 나타났다. 따라서 중 ㆍ고등학교의 학교교육에서도 학생들에게 프로젝트형 탐구학습 프로그램의 적용은 물론 토론식 수습을 통한 학생들의 사고의 전환의 기회를 제공해야 할 것으로 사료된다. The creativity competition was held to foster the creativity of elementary and secondary school students in the Institute of Science Education, Kongju national University. It was found that the creativity competition effected on the improvement of inventing creative ideas and problem solving activities. But, only some competitors participated in semifinal and final contests, presented original and interesting ideas. More female students participated in competition than last year. More female participants were awarded a prize than males. Totally, participants were defective in discussion and communication, and presentation and listening ideas. Increasing grades correlated inversely with creativity and originality. There is need of inquiry project teaming programs and presenting opportunities of conversion of thinking by discussing instructions in school

비인강폐쇄부전 환자의 언어교정을 위해 발음 보조장치를 이용한 증례

김은주,고승오,신효근,김현기 한국음성과학회 2002 음성과학 Vol.9 No.4

VPI occurs when the velum and lateral and posterior pharyngeal wall fail to separate the nasal cavity from the oral cavity during deglutition and speech. There are a number of congenital and acquired conditions which result in VPI. Congenital conditions include cleft palate, submucous cleft palate and cogenital insufficiency (CPI). Acquired conditions include carcinoma of the palate or pharynx and neurologic disorders. The speech characteristics of VPI is characterized by hypernasality, nasal air emission, decreased intraoral air pressure, increased nasal air flow, decreased intelligibility. VPI can be treated with various methods that include speech therapy, surgical procedures to reduce the velopharyngeal gap, speech aid prosthesis, and combination of surgery and prosthesis. This article describes four cases of VPI treated by speech aid prosthesis and speech therapy with satisfactory result.

Roxythromycin-tylosin-furaltadone 합제의 닭 유래 세균에 대한 시험관내 항균효과

김지영,채미경,윤효인,서상희,박배근,김현수,전무형 충남대학교 수의과대학 동물의과학연구소 2003 動物醫科學硏究誌 Vol.11 No.-

In vitro antimicrobial susceptibility of roxythromycin (Rx), tylosin (Tyl), erythromycin (EM) and furaltadone (Fur) was studied, either by the single type or the combinated type of Rx-Tyl-Fur (RTF) against E. co1i (30 strains), Staph. aureus (20 strains) and Mycoplasma gallisepticum (5 strains) that are the major pathogens in poultry farm. The paper disk diffusion and MIC tests were applied. In screening test by paper disk diffusion method, the single types of antibiotics showed the sensitivity against 55 strains of bacteria in order of Fur, EM, Rx and Tyl. The combinated RTF showed the higher rate of sensitivity (80∼83.3% at 64㎍/disk, 60-75% at 32㎍/disk) and wider range of growth inhibiting zone (19.6±3.7-24.8±4.7mm) than those of the single drugs. In MIC test, the sensitivity against the 55 strains appeared in order of Fur. EM, Rx and Tyl as similar to those of paper disk diffusion method. The MIC ranges of RTF were 0.125∼16㎍/ml for E. coli, 0.25∼16㎍/ml for Staph. aureus and 1-8㎍/ml for Myco. gallisepticum, showing evidently lower than those of the single types. The MIC_(50) and MIC_(90) of RTF were estimated l∼4㎍/ml and 8∼16㎍/ml, respectively, and remarkably lower than those of the single drugs.

Kirschner wire를 사용한 과두하 골절의 구강내 접근법

김성일,김승룡,백진아,고승오,신효근 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.3

The treatment of mandibular subcondylar fractures is a matter of controversy. The majority of mandibular subcondylar fracture are treated by closed reduction, but the displaced or dislocated mandibular subcondylar fractures may be treated by open reduction. The characteristics of open reduction are the anatomical reduction, the functional restoration, the rapid function, the maintenance of vertical ramus dimension, the better appearance and the less resultant TMJ problem etc. When an open reduction is considered, the wire, miniplate, lag screw and Kirschner wire are available with internal fixation. Of these, Kirschner wire is a simple method relatively and correct positioning of the wire achieves rigid fixation. But many open reduction methods for mandibular subcondylar fractures require extraoral approach. The extraoral approach has some problems, the facial scar and the risk of facial nerve injury. On the other hand, the intraoral approach eliminates the potency of the facial scar and the facial nerve injury, but is difficult to access the operation site. Since the intraoral approach was first described by Silverman (1925), the intraoral approach to the mandibular condyle has been developed with modifications. The purpose of this article is to describe the intraoral technique with the Kirschner wire on mandibular subcondylar fractures. Conclusion : The intraoral reduction with Kirschner wire on mandubular subcondylar fractures avoids the facial scar and facial nerve injury and is simple method to the extraoral approach. And it has minimal morbidity and better esthetics.

프랑스어 및 한국어 구강모음의 비교연구 : 컴퓨터 단층 촬영 및 디지틀 음향분광기를 사용하여 by means of Computed Tomography and High-speech Analysis System

김찬양,신효근,홍기환,김연희,김현기 全北大學校 語學硏究所 1994 어학 Vol.21 No.-

The methods of the Computed Tomograph and the High-speed Speech analysis system were used for the comparative study of French and Korean oral vowels. Three male native speackers of French and three Korean speakers were selected for these articulatory and acoustic characteristics. The speech materials were the simple French oral vowels / i, e, ε, a, u, o, ??, a / and the Korean oral vovels / i, e, ε, a, w, u, o /, respectively. The results of these studies are as follows : (1) In the case of articulation, the aperture of Korean closed front unrounded vowels is larger than that of French vowels and the Korean back closed vowel /u/ and the half-closed vowel /o/ did not show significant differences with the corresponding French high vowel /i/. But the aperture of the Korean half-open vowel /??/ is smaller than that of French vowel and in this case, the place of articulation for Korean vowel /??/ is more advanced than that of French vowel /??/ (2) By means of spectrographic analysis of the French and Korean vowels, the first formant of the Korean high vowel /i/ is higher than that of French high vowel /i/. This means that the aperture of the Korean high vowel is larger than that of French high vowel. The second formant of French back vowels are lower than those of Korean back vowels. This result shows that the projection of French back vowels is greater than that of Korean back vowels.

시차주사열량분석기를 이용한 치과용 접착시멘트의 경화기전 및 반응열에 관한 연구

김철위,이용근,윤태호,김효종,남세진 大韓齒科器材學會 2000 대한치과재료학회지 Vol.27 No.3

The working time of dental cement has a close relation with the setting time, where the setting reaction can be said as the result of the chemical reaction between cement liquid and powder. The purpose of this experiment was to investigate the setting characteristics and setting rate of dental cements by measuring the exothermic heat(Joule/gram) from the setting reaction at specified times using a differential scanning calorimeter (Differential Scanning Calorimeter, DSC 204, TASC 414/3A Controller, Netzche, Germany). Graphs of time-exothermic heat at 37℃ isothermal condition, showing the setting reaction of dental cements were plotted. Three types of luting cements studied were zinc-phosphate cement (ZPC), polycarboxylate cement (PCC), and glass ionomer cement (GIC). The effects of powder-liquid ratio on the setting characteristics of cements were also included. The amount of heat (calory) released per one gram of cement was calculated at each specified time, and was analyzed. ANOVA and Scheff's multiple comparison test (p=0.05) were used for statistical analysis using SPSS/PC+. The setting rate of cement was not constant during the setting reaction, and different setting characteristics were observed depending on the type of cement and powder/liquid ratio. Generally, 70∼90% of the setting reaction, measured by the exothermic heat release, occurred within 5 minutes after mixing. The exothermic heat released by ZPC was very high immediately after mixing, and the duration of the heat release was prolonged compared with other cements. The exothermic heat release of PCC finished most rapidly. It was generally observed that the amount of heat release (rise in temperature) per one gram of cement was highest for ZPC, followed by GIC, and then PCC. However, heat release during the first 2∼5 minutes after mixing was highest for GIC, followed by ZPC and then PCC. According to the Scheff's multiple comparison test, the duration of the total setting reaction did not show any significant difference among the cements(p>0.05), and also among the different power/liquid ratio groups(p>0.05). It was observed that more heat was released with the lower powder/liquid ratio than the higher powder/liquid ratio.

인삼 재배토양에서의 Procymidone 흡착 및 분해

김효근,이윤환,이규승 한국환경농학회 2002 한국환경농학회지 Vol.21 No.4

인삼재배환경에서의 농약의 동태를 구명하기 위하여 살균제 procymidone을 공시하여 인삼 재배토양을 대상으로 흡착실험을 수행하였다. 또한 procymidone을 처리한 인삼재배토양을 10℃ 및 25℃의 항온에서 배양하면서 토양중 잔류성을 조사하였다. 흡착실험을 통하여 구한 procymidone의 유기탄소기준 흡착분배계수(K_(oc))는 531~743 수준으로서 토양 중 procymidone의 이동성은 낮을 것으로 판단되었다. 실내 항온배양 실험결과로부터 계산된 procymidone의 반감기는 248일(25%) 및 330일(10%)로서 포장실험결과에 비해 현저히 길어졌으며, 이는 procymidone이 가수분해 또는 미생물에 의한 분해 등에 안정한 화합물임을 시사하였다. This work has been conducted to investigate the behavior of pesticides in ginseng(Panax ginseng C. A. Meyer) cultivation environment, with a fungicide procymidone as a model pesticide. Procymidone adsorption on ginseng cultivating soil was studied and persistency of procymidone in soil was monitored in indoor incubation experiments at 25℃ and 10℃. The soil adsorption coefficients(K-(oc)) of procymidone were in the range of 513~743 suggesting the mobility of procymidone in soil is relatively low. Procymidone showed higher persistency in soil under indoor incubation condition than outdoor field condition. The half lives estimated from the first order reaction kinetics were 248 days and 330 days at 25℃ and 10℃, respectively.

구개열 아동 언어의 진단 평가

신효근,고승오,홍기환,서정환,고도흥,김현기 大韓顎顔面成形再建外科學會 1998 Maxillofacial Plastic Reconstructive Surgery Vol.20 No.1

비등 40% MgCl_2 용액에서 22Cr5Ni2Mo 2상 스테인리스강 용접재의 응력부식균열 특성

김효종,이성근 동아대학교 공과대학부설 생산기술연구소 1996 生産技術硏究所硏究論文集 Vol.1 No.2

The microstructure and stress corrosion cracking behaviors in 22Cr5Ni2Mo suplex stainless steel weldment have been investigated. The SCC has been examined in terms of relevant electrochemical parameters in boiling 40% MgCl₂solution. The austenite content of the weld metal had twice as much as that of the base metal due to the effect of additive elements Ni, N and reheat effect by the multipass welding. The steel had the threshold stress of 29.1 kg/㎟ and the critical cracking potencial(E_CC) of -410mV immune to the SCC, and possessed superior SCC resistance compared to the austennitic stainless steel. Above the E_cc the SCC of the weldment occurred at the base metal regardless of the welding method. Cracks were initiated and propagated transgranularly without retarding effect by the phase the austenite phase in high stress region.