초음파 반사 패턴과 주파수 대역 분할 신호처리를 이용한 다층구조인 노내 간극 측정

구길모,심철무,김종환,김상백,김희동,박치승 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.4

모의 원자로내 용융물 냉각 실증 실험 결과 용융물 Al₂O₃/Fe themite 와 lower head vessel사이에 간극이 발생된다. 간극을 정량적으로 측정하기 위한 기존의 초음파 방법은 구조물의 복잡성과 2300℃ 에서 용융되는 thermite Al₂O₃/Fe, Al₂O₃의 영향으로 발생되는 lower head의 열영향부위(HAZ)의 금속학적인 결정입자 크기의 변화로 결정 계면으로부터 발생되는 잡음신호와 초음파 산란, 감쇠, 모드 변환 등이 발생되어 신뢰성이 떨어지고 있다. 간극을 정량적으로 측정하기 위해서 thermite와 lower head 사이에 물이 체워진 형태의 즉 고체, 액체, 고체의 다층구조에서 초음파의 진행 및 반사 형태를 분류 및 분석하였다. 결정립의 잡음을 억제하기 위하여 주파수대역의 확률 처리 방식인 PT(polarity threshold) 알고리즘을 이용하여 약 6dB 신호 대 잡음비의 개선효과를 가져왔다.

자가 산부식 프라이머의 적용시간이 상아질의 미세인장 결합강도에 미치는 영향

조영곤,이영곤,김종욱,박병철,김종진,최희영,진철희,유상훈 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.5

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (μTBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. μTBS was tested and statistically compared using by one-way ANOVA and Tukey's Test. The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased μTBS to dentin.

복합레진의 지연충전이 미세인장 결합강도에 미치는 영향

박현식,조영곤,박병철,김종욱,최희영,김종진,진철희,유상훈,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this study was to evaluate the effect of immediate or delayed composite resin filling on dentinal microtensile bond strength (μTBS) after applied the adhesive. The coronal dentin of human third molars was exposed. Single-Bond or One-Step was applied on the dentin surfaces, and composite resin were constructed immediately (group 1) or 5 min., 10 min., 15 min., 20 min. and 30 min. (groups 2-6) after an adhesive was applied. The specimens were sectioned and made bar-shaped. Each surface area of them was about l ㎟. The RBS test was performed by EZ test. The results were analysed by One-way ANOVA and Tukey's test at 95 % significance level. The results suggested that the μTBS of Single-Bond to dentin was decreased when the composite resin was constructed 20 min. and 30 min. after Single-Bond was applied. But the μTBS of One-Step was not affected by delayed composite resin filling.

법랑질 접착에 대한 습윤 효과

고근호,조영곤,진철희,유상훈,김종욱,박병철,기영재,최희영,김종진 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

This study evaluated the microleakage and interfacial gap between enamel and composite resin under the dry and wet condition of the enamel surface, V shaped class 5 cavities were prepared on the occlusal portion of extracted human molars. Samples were divided into three groups: D group (air dry for 10-15s), BD group (blot dry with moist cotton pellet), and DR group (air dry for 10-15s and rewet with Aqua-Prep F for 20s). Cavities were filled using Aelitefil composite resin after applied One-Step. Microleakage was tested by 2% methylene blue dye solution and the data were statistically analysed by Kruskal-Wallis test and Mann-Whitney test. Also Enamel-resin interface was observed under SEM. Group BD showed statistically lower microleakage than group D (p〈0.05). but there was no statistically significant difference between group BD and DR (p)0.05). At the enamel-resin interface, group D showed the gap of 2 ㎛ thickness, but group BD and DR showed close adaptation. In conclusion, the use of blot dry and rewetting agent (Aqua-Prep F) resulted in decreased microleakage and improved adhesion between enamel and resin when using One-Step.

Meso-Dihydroguaiaretic Acid Isolated from Saururus chinensis Inhibits Cyclooxygenase-2 and 5-Lipoxygenase in Mouse Bone Marrow-Derived Mast Cells

Tae Chul Moon,Chang Seob Seo,Kyungmi Haa,Jin Cheul Kim,Nam Kyung Hwang,Tae Gyun Hong,Jee Hyeun Kim,Do Hun Kim1,손종근,장현욱 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.5

Meso-dihydroguaiaretic acid (MDGA) is a medicinal herbal product isolated from the aerial parts of Saururus chinensis that inhibits the cyclooxygenase-2 (COX-2)-dependent phase of prostaglandin D2 (PGD2) generation in bone marrow-derived mast cells (BMMC) (IC50 9.8 μM). However, this compound did not inhibit COX-2 protein expression in BMMC at concentrations up to 30 μM, indicating that MDGA directly inhibits COX-2 activity. In addition, this compound consistently inhibited the production of leukotriene C4 (IC50 1.3 μM). These results demonstrate that MDGA inhibits both COX-2 and 5-lipoxygenase. Furthermore, this compound strongly inhibited the degranulation reaction in BMMC (IC50 11.4 μM). Therefore, this compound might provide a basis for novel anti-inflammatory drug development.

WBI 교수모형을 이용한 페트리 네트 학습의 설계 및 구현

김경민,노철우 신라대학교 교육과학연구소 1999 교육과학연구 Vol.- No.4

마이크로프로세서를 이용한 3상 5레벨 PWM 인버어터에 관한 연구

金喆禹,金龍雄 부산대학교 공과대학 1985 硏究報告 Vol.30 No.-

Three phase 5-level PWM inverter using z-80 microprocessor is described. Microprocessor is used to generate reference wave and carrier wave, and to compute switching points for PWM patterns. By variation of modulation index M and frequency ratio R, inverter's output voltage is controlled in the real time. Harmonic components are analyzed theorically and experimentally. The experimental results agree with the theorical value and CVCF operation is suitable at the modulation index M=1.3~2.0.

응급실 환아에 대한 임상통계적 관찰

김진헌,박철원,나창수 朝鮮大學校 附設 醫學硏究所 1986 The Medical Journal of Chosun University Vol.11 No.1

The studies were carried out to analyze the emergency patient visited to the emergency room of Chosun University Hospital under 15years of during the four-year period from Jan., 1982 to Dec., 1985. The results were obtained as below. 1) During the 4 year periods, the total number of emergency patients under the 15years of age was 5,122. 2) Fifty two percents of the total patient were admitted. 3) Deaths bsfore arrival to emergency room were 41 cases and deaths during managements at emergency room were 8 cases. 4) The total number of the male patients was 3,299 and that of the female, 1,823. 5) The most popular time of visiting to emergency room was between 4 : 00 PM and 12 : 00 PM 6) Monthly distribution of visits revealed higher incidence in Aug. and Sep. and lower incidence in Jan. and Feb. 7) Weekly distribution of visits revealed higher incidence on Sunday relatively. 8) Distribution of age showed peak incidence was below 2years of age(36.6%) 9) The number of patients received urgent management was 910 and the content was as below : O₂ inhalation(36.9%), Dressing(17.4%), Primary suture(13.9%), G-tube and lavage(7.9%), Barium reduction (6.9%). 10) Distribution of diseases and injury in according to the WHO's International Classification of Diseases was as below in order : Injury and poisoning'(28.6%), Ill-defined symptoms and signs(25.5%) .Infectious disease(13.7%), Respiratory disease(ll.6%), Perinatal problems(7.4%), Nervous system disorder(5.0%), Digestive discase(4.5%). 11) Distribution of patient's address was as below : Kwangju(57.0%), Rural(38.3%). 12) Most frequent primary diagnosis of emergency cases were as below : Injury and poisoning, diarrhcal disorder, URI, pneumonia.

利益變動原因分析의 모델

金喆鎬 弘益大學校 1982 弘大論叢 Vol.14 No.1

This paper provides some tools to analyze variation factors is a firm's normal profit. For the purpose of developing these, this abstract begins with the analysis of variation causes in sales, cost of goods sold, operating expenses and the other revenues. and expenses, and finally concentrates on the correlation analysis of cost-volume-profit. 1. Analysis of variation in sales Increase of market price & decrease of quantity: ΔS_a=(P'-P)Q'+P(Q'-Q)={P(1+r₁)-P}Q'+P{Q(1-r₂)-Q} Decrease of market price & increase of quantity: ΔS_b=(P'-P)Q+P'(Q'-Q)={P(1-r₁)-P}Q+P'{Q(1+r₂)-Q} Increase (or Decrease) of market price & quantity: ΔS_c={(P'-P)Q+½(P'-P)(Q'-Q)}+{P(Q'-Q)+½(P'-P)(Q'-Q)}={[P(l±r₂)-P)Q+½P(1±r₁)-P)][Q(l±r₂)-Q]}+{P[Q(1±r₂)-Q)+½P(1±r₁)-P][Q(l±r₂)-Q]} (S:sales, P:previous market price, P':current market price Q:previous. quantity, Q':current quantity, r₁:rate of variation in price, r₂:rate of variation in quantity) 2. Analysis of variation in CGS. Increase in CGS per unit & decrease in quantity: ΔC_(pa)=(p'-p)Q'+p(Q'-Q) Decrease in CGS per unit & increase in quantity: ΔC_(pb)= (p'-p)Q+p'(Q'-Q) Increase (or Decrease) in CGS per unit & quantity: ΔC_(pa)={(p'-p)Q+½(p'-p)(Q'-Q)}+{p(Q'-Q)+½(p'-p)(Q'-Q)} (p : previous CGS per unit, p' : current CGS per unit) 3. Analysis of variation in operating expenses Increase in the rate of operating variable expenses per unit &decrease in quantity: ΔC_(o₁)=(f_0'-f_0)+(p'·r₄'-p·r₄)Q'+p·r₄(Q'-Q) Decrease in the rate of operating variable expenses per unit & increase in quantity: ΔC_(o₂)=(f_0'-f_0)+(p'·r₄'-p·r₄)Q+p'·r₄'(Q'-Q) Increase (or Decrease) ,in the .rate of operating variable expenses per unit & quantity: ΔC_(o₃)=(f_0'-f_0)+{(p'·r₄'-p·r₄)Q+½p'·r₄'-p·r₄)(Q'-Q)}+{p·r₄(Q'-Q)+½p'·r₄-p·r₄)(Q'-Q)} (f_0 : previous operating fixed expenses, f_0' : current operating fixed expenses, r₄ : previous rate of operating variable expenses, r₄' : current rate of operating variable expenses) 4. Analysis of variation in the other revenues & expenses. Other revenues: ΔN₁=(I₁'-I₁)+(A₁'-A₁)+(M₁'-M₁) Other expenses: ΔN₂=(I₂'-I₂)+(D'-D)+(A₂-A₂)+(M₂'-M₂) (I₁ : receivable interest, I₂ : payable interest, A₁ : valuation income, A₂ : valuation expense, D : depreciation, M₁ : miscellaneous income, M₂ : miscellaneous expenses) :5. Analysis of the correlation of cost-volume-profit. Gross Margin (G₁) : ΔG₁=ΔS-ΔC Operation Margin (G₂) : ΔG₂=ΔS-(ΔC+ΔC_0) Normal profit (Earning before special gains or losses & income taxes)(G₃) : ΔG₃=(ΔS+ΔN₁)-(ΔC+ΔC_0+ΔN₂) (N₁ : non-operating income, N₂:non-operating expenses) 'Since the ultimate purpose of analysis of variation in profit is to provide some informations for management, the further analysis for each product, region & customer in sales has to be included in the study on the variation in margin. Therefore, I think,. a more careful and sufficient study on this field should be forthcoming.

Marketing Planning의 數理 모델

金喆鎬 弘益大學校 1974 弘大論叢 Vol.6 No.-

The purpose of this paper is to discuss the use of mathematical modes as tools for marketing planning. When the uses or applications of a mathematical-model approach are discussed, some arguments against their use are often offered-for instance, the arguments against the fallacy of model-builder, the disregard for managerial human judgement, the use of technical terms unfamiliar to the average person, or against uncertain forecast by means of past data analysis. Nevertheless, we must recognize worthwhile advantages of mathematical methods, they keeping a well-defined statement of the problem and logical means for utilizing all avalable information to develop more realistic and efficient marketing. In closing, it is sure that mathematical methods and models are effective within the limits as tools for decision-marketing in marketing. The essential formulations in this paper are as follows. 1. t??-t₁=(a-a')+(b-b')t₁……dynamic allowed term of installment sale b' 2. S??=F+r·f ……objective sales amount 1-v-r·u 3. P??=v-a……optimum price 2 2e 4. n=P(1-P)……size of sampling t²δ² 5. P=N(P±t·δ)……examination of probablity for universe 6. X??=S{E(N+1)-Q??}……area sales-quota E(N+1)N