국립김해박물관 개관 전시유물 보존처리 보고

권혁남,안병찬 국립중앙박물관 1999 박물관보존과학 Vol.1 No.-

국립김해박물관의 개관을 위해 전시유물 200여점을 보존처리 하였다. 처리유물은 대부분 고분출토품이며 재질은 금동, 은, 구리합금제, 철제 등 금속유물이 주종을 이루고 있다. 모두 고대 가야문화를 대표하는 문화재들이다. 유물은 상태에 따라 처리방법을 달리했다. 구리합금제 유물은 부식물의 안정성에 따라 보존과 제거를 결정했다. 특히 철제품의 경우 현재 안정한 상태의 유물은 물리적인 방법으로 이물질을 제거해 원형을 찾고 방녹제[상품명 : Ballistol]를 이용해 부식을 예방하는데 중점을 두었다. 부식이 진행중인 유물은 원인제거를 위해 2단계 탈염처리를 했다. 제 1단계는 0.3M NaOH 용액함침, 제 2단계는 붕사-증류수 가압탈염법이다. 이밖에 전시를 위한 특수 받침대제작 및 각종 전시보조물인 모형 등에 대한 수정작업도 지원했다. More than 200 objects selected for the newly-opened Gimhae National Museum were treated for conservation. The objects which represent ancient Gaya culture. were mainly composed of metallic such as gilt bronze, silver, copper alloy and iron. The corrosion products on gilt bronze and copper alloy objects were preserved or removed according to their stability. Minimum treatment was done for preserving the original state of the objects. For silver objects and iron objects with silver-plate decorations, silver surfaces were revealed after treatment of corrosion products and treatments to prevent corrosion of silver and iron were done emphatically. For iron objects, which were stabilized, the original shape of objects was restored and acrylic coating was applied to prevent further corrosion. For the objects which were being corroded, 2-step de-chloride treatments were undertaken. The first step was immersing the objects in a solution of 0.3M sodium hydroxide and the. second was the pressure de-chloride treatment using borax-distilled water. The main purpose of those treatments was to get rid of the causes of corrosion. Besides, conservation treatments for potteries, making of special mounting board for exhibition and amendment of various modeling were done too.

지속성 외래복막투석 환자들의 예후에 영향을 미치는 요인들에 관한 고찰

권혁만,김찬덕,조지형,장민화,최혁준,이현철,박자용,박선희,김용림 대한신장학회 2004 대한신장학회잡지 Vol.23 No.2

冷間押出用 헬리컬기어 金型의 强度解析

崔載燦,權赫洪,辛榮柱 부산대학교 공과대학 1992 工大論文集 Vol.44 No.-

In forging die design, pre-stressing is useful in preventing excessive tensile circumferential stresses which may cause die failure during forming. The finite element analysis (F.E.A.) package ANSYS reversion 4.4 A was used to this study. F.E.A., that is, static analysis was accomplished for insert-dies of helical gear. Die model was constructed with 8 node isoparametric solid finite elements. Static load analysis was performed for internal and outer pressure. Also, stress distribution and deformed shapes are shown. To assure durability and reliability, failure analysis was calculated by maximum normal stress theory and distortion energy theory. Results of the F.E. analysis and failure analysis for Samanta and new process dies were compared. The results of F.E. Analysis were in good agreement with that of experimental results. It is expected that the results of this study can be applied to designing various kinds of extrusion gear die.

수신부인방지를 제공하는 E-mail기반의 인터넷 EDI 보안 메커니즘

김준범,권혁인,김영찬 중앙대학교 정보통신연구소 1999 정보통신연구소논문집 Vol.1 No.1

개방형 특성을 가지는 인터넷을 사용함으로써 누구나 자유롭게 인터넷 EDI 시스템을 사용할 수 있게된 반면 이러한 개방성은 보안의 측면에서 중요한 정보 전달 시에 정보가 누출될 수 있다는 문제점을 가진다. 이러한 정보 노출은 전송하려는 정보를 암호화하여 송 ·수신함으로써 방지할 수 있다. 이메일 기반의 IEDI 시스템을 위한 보안 해결책은 S/MIME 프로토콜과 PGP 보안 메커니즘이 있다. 본 논문에서는 S/MIME과 PGP를 분석하여 이메일 기반의 안전한 문서 전송을 위해 기밀성, 무결성, 인증, 송 ·수신 부인 방지의 기능을 제공할 수 있는 보안 메커니즘을 설계 및 구현하였다. The openness of Internet has not only the property that everybody use the IEDI systems freely but also security problem that informations are leaked in transferring. The leakage of information is protected by encryption of data. Security solutions for e-mail based IEDI system are S/MIME protocol and PGP security mechanism. In this paper, security mechanism that providing confidentiality, authentication, integrity, sender/receiver non-repudiation for secure transferring of IEDI documents are designed and implemented

冷間押出 헬리컬기어의 精密度 向上에 관한 硏究

崔載燦,權赫洪 부산대학교 공과대학 1992 工大論文集 Vol.44 No.-

A new extrusion process of helical gear was proposed and developed. For the manufacturing of extrusion die, and electrical discharge machining was applied, where an electrode for E.D.M has been designed by a developed CAD program. The precision of cold extruded gear is associated with the over-burn in E.D.M, lapping and elastic expansion of die etc., so it can be improved by proper compensation about them in die manufacturing. In the experiment, tolerances of shaved gears after extruded fell within 4~5 class KS standard. Therefore, the cold extrusion process can be used as an advanced technique to replace the conventional hobbing process.

뇌자도 측정을 위한 저잡음 Nb SQUID 센서의 설계 및 제작

이용호,권혁찬,김진목,이상길,임청무,박용기,박종철 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

We report on the design, fabrication and performances of a low-noise Nb SQUID sensor for neuromagnetic measurements. The main features of the developed sensor are i) large flux-to-voltage transfer, making the SQUID readout electronics simple, and ii) use of the integrated planar pickup coil to eliminate the environmental magnetic field noises. The magnetic field noise of the developed SQUID sensor is below 5 fT/√Hz at 100 Hz, which is low enough to be used in neuromagnetic measurements.

냉간압출에 의한 새로운 헬리컬기어의 제조에 관한 연구

崔載燦,趙海龍,權赫洪 부산대학교 공과대학 1991 工大論文集 Vol.42 No.-

A new helical gear forming process by cold extrusion was proposed and its numerical solution program based on the upper bound method was developed. In the analysis the involute curve was used as a shape of die and the upper bound method was used to calculate energy dissipation rate. By this method the power requirement and optimum conditions necessary for extruding helical gear were successfully calculated. These numerical solutions were in good agreement with experimental data. In the experiment, die life of a new was greatly improved compared with hat of Samanta process and 4~5 class helical gear of KS standard for automobile transmission was successfully manufactured.

임신 생식관련인자와 비만위험

장기홍,권혁찬,이득주,유희석,이은주,한인권 대한비만학회 1995 The Korean journal of obesity Vol.4 No.1

It is thought Omt there is a close relationship between obesity and pregnancy, but there are not any concrete studies in Korea. Therefore, a retrospective study was conducted to evaluate how factors surrounding pregnancies affect the body mass index. 385 women who had no history of disease or medication as a cause of obesity were randomly selected, and factors vlated to pregnancy vi ere compared between a normal body mass index group and a group where the body mass index was more thsn one standard deviation from the average. The average age of the study group was 44,25 years(S.SS) and the average body mass index was 23.09 kg/m2(3.00). 4 the obese group the average age was statistically higher, the level of education was statistically lower, but there was no statistica] difference with regard to smoking, alcohol consumption and exercise. Age showed to be statistically significant positive correiation with body mass index, but the level of education showed negative correlation. The age of first pregnancy, age of first delivery, and the mterval between menarche and first pregnancy showed statistieally significant negative correlation with the body mass index, whereas the duration of lactation, total number of pregnancies showed statistically significant positive correlation with body mass index. There was statistical1y significant more deliveries in the group where the body mass index was more than one standard deviation frvm the average, the risk for obesity was 2.5 times higher in women who had three or more deliveries compared to those who had less than three deliveries, and the risk was 1.5 times higher in women who had their first delivery before the age of 25 years compared to those over the age of 25 years. But other factors were found not to be different between the two study group and were independent of age, level of education, aleohol consumption and smoking. It can be seen from these results that pregnancy related factors are related to obesity, and that especially age, level of education, alcohol consumption and smoking independantly increase the risk for obesity. Also those women who have had more than three deliveries or who had their first pregnancy before the age of 25 years were at risk, and there should be a formulative plan for these women. It is hoped that in-depth study of pregnancy factors contributing to obesity be determined with further study and research.

Al-Si합금용탕과 Al₂O₃의 젖음성에 관한 연구

朴昌宣,金鍾贊,朴相俊,權赫茂 忠南大學校 産業技術硏究所 1992 산업기술연구논문집 Vol.7 No.1

The purpose of this study is to obtain basic infotmation on the wettability of pure-Al/Al₂O₃, Al-alloy/Cu, Al-alloy/Ni and Al-12%Si/Al₂O₃systems, by using the Sessile drop method. The wettability of Al alloy-melt on Al₂O₃increases with increasing temperature from 750℃ to 850℃ for Al-12%Si-y% (Cu, Zn and Mg) (y:0∼2)/Al₂O₃system, the contact angle decreases with increasing Cu, Zn and Mg content. The wettability of Al alloy on Cu and Ni-palte is better than that on Al₂O₃-plate : this is attributed to the interfacial reaction between the Al aiioy and the metal substrate.

동일한 환자에서 조혈모세포이식 전후의 호중구감소 기간 중 감염양상에 대한 비교연구 : 중심정맥관 관련 패혈증을 중심으로 Based on Central Venous Catheter Related Septicemia

류재호,노규태,이영석,이영호,권혁찬,김재석,김효진,이영민,박혜원,박근희 대한조혈모세포이식학회 2002 대한조혈모세포이식학회지 Vol.7 No.1

연구배경: 동일한 환자를 대상으로 조혈모세포이식 전 일반 병실에서의 관해유도 항암제치료 및 강화요법으로 인한 호중구감소 기간의 감염양상과 고용량 항암제치료 후 무균실에서의 조혈모세포이식 시 호중구감소 기간의 감염양상을 중심정맥관 관련 패혈증을 중심으로 비교 연구함으로써 효율적인 감염관리지침을 마련하고자 하였다. 대상 및 방법: 1999년 1월부터 2001년 7월까지 2년 7개월간 동아대학교병원 일반병실에서 악성혈액질환으로 항암제 치료를 받다가 조혈모세포이식을 시행받았던 22명을 대상으로 중심정맥관 관련 패혈증의 형태를 비교분석하였다. 결과: 대상 환자들의 일반병실과 무균실에서의 입원기간은 각각 32±13일, 33±19일, 호중구 감소기간은 15±12일, 17±18일, 호중구 감소기간의 발열 횟수는 14회, 14회로서 입원병실의 종류에 따른 차이는 없었다. 환자들의 중심정맥관 사용일수는 일반병실에서 29일(7~545일), 무균실에서 100.5일(25~606일)이었으며, 총 사용일수는 각각 1,515일, 3,250일로서 무균실에서의 중심정맥관 사용일수가 의미 있게 길었다(P=0.001). 중심정맥관 사용 일수에 대한 감염률은 각각 5.28/1,000일, 3.08/1,000일로서 일반병실에서 그 빈도가 높았으나 통계적 유의성은 보이지 않았다(P=0.141). 결론: 중심정맥관 삽입 후 일반병실에서 항암제 치료를 받던 환자가 조혈모세포이식을 위하여 무균실에 입원하는 경우, 중심정맥관을 교체하는 것이 감염관리를 위하여 바람직할 것으로 생각된다. Background: We compared the incidence of central venous catheter (CVC) related septicemia during neutropenic period in the same patient, which developed following chemotherapy for remission induction and consolidation, or hematopoietic stem cell transplantation (HSCT). Methods: We retrospectively reviewed the medical records and laboratory data of 22 patients with hematologic malignancies who received anticancer chemotherapy followed by HSCT at Dong-A University Hospital between January, 1999 and July, 2001. We investigated the duration of hospitalization, duration of neutropenic period, duration of catheterization, microbiologically documented organisms and incidence of CVC related septicemia. Results: The data in general ward (before HSCT) and laminar air flow room (after HSCT) were as follows: duration of hospitalization was 32±13 days and 33±19 days, duration of neutropenic period was 15±12 days and 17±18 days, median duration of catheterization was 29 days (7~545 days) and 100.5 days (25~606 days) (P=0.001), and incidence of CVC related septicemia was 5.28/1000 days and 3.08/1000 days, respectively. In the CVC related septicemia, the most common etiologic organism was coagulase negative staphylococcus. Conclusion: We suggest that the exchange of CVC before admission to laminar air flow room could decrease the incidence of CVC related septicemia in HSCT recipients.