• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.1
• /
• pp.23-28
• /
• 2008

In this paper, transient characteristics of the Punch Through Insulated Gate Bipolar Transistor (PT-IGBT) have been studied. On the contrary to Non-Punch Through Insulated Gate Bipolar Transistor(NPT-IGBT), it has a buffer layer and reduces switching power loss. It has a simple drive circuit controlled by the gate voltage of the MOSFET and low on-state resistance of the bipolar junction transistor. The transient characteristics of the PT-IGBT have been analyzed analytically. Excess minority carrier and charge distribution in active base region, the rate of anode voltage with time are expressed analytically by adding the influence of buffer layer. The experimental data is obtained from manufacturer. The theoretical predictions of the analysis have been compared with the experimental data obtained from the measurement of a device(600 V, 15 A) and show good agreement.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.703-707
• /
• 1997

DUe to the requirement of high precision and the complexity during the tool design for electron gun elements, it sometimes causes human-errors. Also, in the case of beginners, they have more trial and error than skilled engineers. To remove these problems and increase the productivity in the practice field, it need the deveiopment of CAD system for electron gun element tools. Through this study, a CAD system of electron gun element tools which is used by used by knowledge base system including expert's technology in the practics, has been developed. To developed this system, it has used C-language under HP-UNIX system and CIS customer language of the EXCESS CAD/CAM system. An application of this system will provide effective aids to the designer in this field.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.1
• /
• pp.69-77
• /
• 1999

This paper describes an expert system of progressive die. Because of the complexity for die structure and of the critical problems for press machine mechanism in the progressive press process such as, the travel length in process, the equalized press load, and the other design parameter, it has been increased the requirement of the CAD system for progressive die design more an more. So, through this study, an expert system of progressive die has been developed. The results from the system developed were suggested the possibility of applications in the practice. To develop this system, it has used c-language under the HP-UNIX system and CIS customer language of the EXCESS CAD/CAM system. An application of this system will provide effective aids to the designer in this field.

• YAKHAK HOEJI
• /
• v.37 no.3
• /
• pp.247-253
• /
• 1993

Eight new derivatives of allylamine which are related to naftifine and expected to have antifungal activity were synthesized. Schiff base 2a-2d and 2'e-2'h were obtained by conventional methods using trans-cinnamylamine or trans-cinnamaldehyde. The reduction of azomethine linkage with NaBH$_{4}$ yielded secondary amine 3a-3h, which were then methylated by means of HCHO and excess NaBH$_{4}$ or HCOOH to give 4a-4h.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.10
• /
• pp.27-33
• /
• 1998

Due to the requirement of high precision and complexity during the die design for electron gun elements, it sometimes causes human-errors. In addition, in the case of beginners, they have more trial and error than skilled engineers. To remove these problems and increase the productivity in the practice field, it needs the development of CAD system for electron gun element progressive die. Through this study, a CAD system of electron gun element progressive die, which is used, by knowledge base system including expert's technology in the practice, has been developed. To develop this system, it has used C-language under HP-UNIX system and CIS customer language of the EXCESS CAD/CAM system. An application of this system will provide effective aids to the designer in this field.

• Journal of Family Resource Management and Policy Review
• /
• v.3 no.1
• /
• pp.105-121
• /
• 1999

The major purpose of this study is to examine the effect of the extracurricular lesson expenses on the Burden of Household Expenditure. The data are collected from 537 housewives with a child aged 18(2nd grade in high school) in Seoul. The statistics used for the data analysis are frequency, percentage, crosstables, one way ANOVA, and multiple regression. The statistic softwear used for this study is SPSS. The Result on a base of empirical analyses follow: 1. Respondentg’s expenditure on extracurricular lesson fees is about 430,000 won per month, which is about 28% of the living cost. 2. There are four types of the methods preparing extracurricular lesson fees: ‘Frugal Type’, ‘Excess Type’, ‘Composit Type’, ‘Self-supportable Type’. 3. Region, the living cost, sex of children, net worth, and the mother’s education show statistically significant effect on the extracutticular lesson expenses. 4. The regression analyses incicate that Burden of Household Expenditure increased by 1.9 point according to 1% increase in expenditure on extracurridular lesson fees. The higher budget share of expenditure on extracurricular fees, the higher level of Burden of Household Expenditure.

• Journal of the Korea Safety Management & Science
• /
• v.8 no.3
• /
• pp.115-123
• /
• 2006

The main focus of this study is to investigate the performance of a clark-scarf type multi-echelon serial supply chain operating with a base-stock policy and to optimize the inventory levels in the supply chains so as to minimize the systemwide total inventory cost, comprising holding and backorder costs as all the nodes in the supply chain. The source of supply of raw materials to the most upstream node, namely supplier, is assumed to have an infinite raw material availability. Retailer faces random customer demand, which is assumed to be stationary and normally distributed. If the demand exceeds on-hand inventory, the excess demand is backlogged. Using the echelon stock and demand quantile concepts and an efficient simulation technique, we derive near optimal inventory policy. Additionally we discuss the derived results through the extensive experiments for different supply chain settings.

• Journal of Veterinary Clinics
• /
• v.20 no.4
• /
• pp.501-503
• /
• 2003

Urolithiasis (UL) is a common disease of canine. Analysis of urinary stone is an essential step in the examination and initial treatment of the patient with UL. The dead maned wolf (Chrysocyon brachyurus), male, was introduced to the Veterinary Teaching Hospital, Chungbuk National University. The maned wolf was imported from USA to Cheong-ju zoo. Postmortem sign of maned wolf was hemorrhage of bladder with a many stones. No bacteria was shown with bacterial culture of urine. But in feces, Clostridium perfringens were overgrown. Bladder stone from maned wolf was composed of calcium oxalate. Calcium oxalate was formed with excess calcium from diet mainly meat base.

• Bulletin of the Korean Chemical Society
• /
• v.9 no.2
• /
• pp.77-80
• /
• 1988

A suituable choice of supporting electrolyte medium for trace level determinations of chromium(VI) by differential pulse polarography is described. A comparative study suggests that sodium borate buffer is superior to ammonium acetate, ammonium tartrate, and especially to NaF which was recently known to be one of the most proper medium for the purpose. With 0.01 M borate, the best combination of high sensitivity, well-defined base line, and freedom from common interferents was attained. With $5.0{\times}10^{-7}$M Cr(VI), tenfold excesses of Cu(II) and Fe(III), and a five hundred-fold excess of $Cl^-$ do not change the peak current by more than about 1%. And the detection limit was $5.0{\times}10^{-8}$M Cr(VI).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.5
• /
• pp.361-367
• /
• 2005

Single nucleotide polymorphisms (SNPs) are valuable DNA markers due to their abundance and potential for use in automated high-throughput genotyping. Numerous SNP genotyping assays have been developed. In this report, one of effective and high throughput SNP genotyping assays, which was named the template-directed dye-terminator incorporation with fluorescence polarization detection (FP-TDI) was described. Although the most of this assay succeed, the objective of this work was to deter­mine the reasons for the failures, find ways to improve the assay and reduce the running cost. Ninety $F_2$-derived soybean, Glycine max (L.) Merr., RILs from a cross between 'Pureunkong' and 'Jinpumkong 2' were genotyped at four SNPs. FP measurement was done on $Victot^3$ microplate reader (perkinelmer Inc., Boston, MA, USA). Increasing the number of thermal cycles in the single-base extension step increased the separation of the FP values between the products corresponding to different genotypes. But in some assays, excess of heterozygous genotypes was observed with increase of PCR cycles. We discovered that the excess heterozygous was due to misincorporation of one of the dye­terminators during the primer extension reaction. After pyrophosphatase incubation and thermal cycle control, misincoporation can be effectively prevented. Using long amplicons instead of short amplicons for SNP genotyping and decreasing the amount of dye terminator and Acyclopol Taq polymerase to 1/2 or 1/3 decreased the cost of the assay. With these minor adjustments, the FP-TDI assay can be used more accurately and cost-effectively.