서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

백서 척수에서 Capsaicin과 Eugenol이 iCGRP (immunoreactive calcitonin gene-related peptide) 분비 조절에 미치는 영향

오원만,김원재,최남기,박상원,황인남,김선현 大韓齒科保存學會 2001 Restorative Dentistry & Endodontics Vol.26 No.5

Neuropeptide such as calcitonin gene-related peptide and substance P may mediate neurogenic inflammation, but little is known about the regulation of neuropeptide release from rat spinal cord. Eugenol has been reported to reduce odontogenic pain and is known to have a structure similar to capsaicin, a potent stimulant of certain nociceptors. This study was done to examine the effect of capsaicin and eugenol on immunoreactive calcitonin gene-related peptide (iCGRP) release from rat spinal cord and whether eugenol regulates capsaicin-sensitive release of iCGRP or it evokes capsaicin-sensitive release of iCGRP. The dorsal half of rat lumbar spinal cord was chopped into 200㎛ slices. They were superfused (500㎕/min) in vitro with an oxygenated Kreb's buffer. The EC50 of capsaicin on iCGRP release was measured. Eugenol (600㎛ and 1.2mM) and vehicle (0.02% 2-hydroxyl-β-cyclodextrin) were administered prior to stimulation of rat lumbar spinal cord with capsaicin. The amount of iCGRP release from rat lumbar spinal cord was measured by radioimmunoassay. The results were as follows : 1.iCGRP release from rat lumbar spinal cord was dependent on concentration of capsaicin. The EC50 of capsaicin on iCGRP release was 3㎛. 2.In the vehicle treated group, capsaicin (3㎛) evoked a 14-fold increase over basal iCGRP level. 3. Administration of 600㎛ and 1.2mM eugenol evoked a 2.2-fold increase and a 2.3-fold increase over basal iCGRP level respectively. 4.Administration of 600㎛ and 1.2mM eugenol increased capsaicin evoked release of iCGRP by more than 50%. These results indicate that eugenol evoke CGRP release from central nervous system and potentiate the pain-inducing action of capsaicin on it Key words : Eugenol, Capsaicin, Rat lumbar spinal cord, Superfusion, Radioimmunoassay

실리콘樹脂를 利用한 文化財保護被膜에 對한 硏究

黃正儀,朴斗元,吳相午,鄭倧在,朴裕哲,郭永佑 慶北大學校 1977 論文集 Vol.23 No.-

金屬실리콘과 鹽化메틸을 鹽化第一구리를 觸媒로 하여 메틸실란을 合成하고 메틸실란을 加水分解하여 실록산의 被膜을 만드는 方法을 調査하였다. 이들 被膜이 文化財 保護被膜이 될 수 있는가를 檢討하기 爲해서 材料를 文化財의 材質인 몇 가지 物質에 適用하여 膜의 性能을 調査하였다. 特히 撥水效果, 汲水量 耐久性等을 調査하였으며 外觀上 아무런 變化가 없는 좋은 被膜이 될수 있다는 結果를 얻었다. The organohalogensilicone was synthesized metal silicone and methylchloride applying the direct synthetic method using copperous chloride as catalyzer. The synthesized organosilane was hydrolyzed to siloxane by various method and coated on various materials which are composed of the cultural assets. The coating film was examined to decide whether it is profitable one to protect the assets from efflorescence or air pollution. Referring to the water repellency, permiability of water and the weather test of the film it was qualified that this film was good enough to apply to the cultural assets as protecting film.

두가지 혈류 유발방법에 의한 새로운 심폐소생술(이중 혈류 유발 심폐소생술)장치의 개발

황성오,김현,조준휘,오범진,임종천,최경훈,윤정한,이승환,김영식,이강현,이윤선 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: There have been many efforts to augment blood flow during cardiopulmonary resuscitation. These efforts have focused on maximizing the effect of cardiac pump or thoracic pump alone. However, considering that the heart is the biggest blood reservoir and increase of intrathoracic pressure can generate blood flow, simultaneous exploitation of both mechanisms may have synergistic effect. We hypothesized that simultaneous chest constriction in addition to sternal compression by standard CPR may have additive hemodynamic effects by preventing deformation of the chest and increase of intrathoracic pressure. Methods and results: we built a new mechanical device to perform compression and thoracic constriction simultaneously. The device consists of two main elements. Piston in the center is to depress the sternum. Strap is to constrict the thorax circumferentially. Strap is attached to both sides of the piston. When the piston is pushed down, it depresses the sternum and pulls on the thoracic strap. To determine strap width to produce optimal hemodynamic effect, we measured hemodynamic parameters with variable widths of strap in two dogs after induction of ventricular fibrillation. Result of the experiment showed that 10cm wide strap was determined to be most effective. We also determined optimal depth of compression to produce maximal hemodynamic effect with animal experiments using two dogs. Animal experiments showed that the highest aortic pressure could be generated when the stemum was depressed to 5 cm. Cardiopulmonary resusciation using a new device could generate higher systolic aortic pressure, coronary perfusion pressure and end-tidal carbon dioxide tension in comparison with standard cardiopulmonary resuscitation in a pilot animal study using two dogs. Conclusion: New cardiopulmonary resuscitation method using a mechanical device designed by us could perform sternal compression and simultaneous thoracic constriction, and generate better hemodynamic effects than standard cardiopulmonary resuscitation in pilot animal experiments.

μBGA 무연솔더 (Sn-3.5Ag-0.7Cu)와 전해 및 무전해 Ni 도금층 계면의 열적 안정성

오성룡,황태복,오용준 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.9

The morphology and thermal stability of the interfacial phases in the joints between lead free solder (Sn3.5AgO.7Cu) and electroless Ni-P (12 at%P) and electro Ni under bumper metallizations(UBM) were investigated as a function of thermal aging. Samples were prepared by reflowing at 250℃, N₂ atmosphere and aging in the range of 125 to 170℃ for up to 1000h. After reflow, in the electrolytic Ni/solder joint, the interfacial IMC was mostly Nirich (Ni,Cu)₃Sn4 with an addition of about 8 at% Cu while in electroless Ni-P/solder joint it showed both Cu-rich (Cu,Ni)_(6)Sny and Ni-rich (Ni,Cu)₃Sn4. After relatively short aging time, the interfacial IMC on electrolytic Ni layer has developed into the dual-layed structure of (Ni,Cu)₃Sn₄(bottom) and (Cu,Ni)_(6)Sny(top). But IMC on electroless Ni-P layer were (Cu,Ni)_(6)Sn_(6) and changed into the dual structure only after long aging time of 500h. The growth rate of IMC with aging was higher on electrolytic Ni layer than on electroless Ni-P. The different behavior of electroless Ni-P/SAC joint came from Ni₃P formation between IMC and electroless Ni-P layer which retards diffusion of Ni and Sn to the opposite direction. The thickness of Ni₃P layer was propositional to that of IMC. For longer aging time, NiSnP layer was found at the interface between IMC and Ni₃P layer. Interestingly, in spite of low consumption rate of electroless Ni-P than electrolytic Ni layer by suppressing IMC growth, the interface of Ni-P/IMC was locally hollowed by the accelerated reaction of the Ni-P layer through local thickness reduction of Ni₃P and NiSnP layers. This reduced the effective remaining thickness of Ni-P layer.

점토광물을 이용한 산소환원의 전기화학적 촉매성에 관한 연구

오성훈,황진연,심윤보,이효민,윤지해 한국광물학회 2005 광물과 암석 (J.Miner.Soc.Korea) Vol.18 No.1

몇 가지 점토광물과 메틸바이올로젠 또는 메틸렌블루를 함유시킨 점토수식전극을 이용하여 산소환원에 대한 전기화학적 촉매성을 검토하였다. 점토광물로는 Na-몬모릴로나이트, Ca-몬모릴로나이트, 카오리나이트를 사용하였다. 점토수식전극은 유리탄소전극 표면에 점토 현탁액을 입히고 메틸바이올로젠을 흡착시킨 것을 사용하였으며, 전기화학적 산소환원의 정도는 순환 전압전류(cyclic voltammetry)으로 측정하였다. 실험결과, 다른 점토시료에 비하여 Na-몬모릴로나이트가 메틸바이올로젠의 흡착효과가 가장 크게 나타났고, 메틸바이올로젠을 흡착시킨 점토수식전극이 산소환원에 대한 촉매성이 월등히 우수하였다. 즉 촉매산소환원 피크가 242.6 ㎷ 만큼 +방향으로 이동하였다. 메틸바이올로젠을 흡착시킨 점토수식전극이 메틸렌블루를 흡착시킨 점토수식전극보다 산소환원에 대한 촉매성이 더 높게 나타났다. Ca-몬모릴로나이트의 경우는 변화가 없었으나 Na-몬모릴로나이트의 구조는 메틸바이올로젠의 흡착으로 변화되었다. 메틸바이올로젠- Na-몬모릴로나이트 점토수식전극을 현탁액의 점토 농도가 약 0.87 g/10 mL이고, 메틸바이올로젠의 수용액의 농도가 대략 2.5 mM일 때 산소환원 촉매 효과가 가장 탁월하였다. 지지전해질의 pH에 따른 점토수식 전극의 산소 환원 촉매성은 중성의 pH 범위(6.3과 8.3)에서보다 산성인 pH 3.7과 알칼리성인 pH12.7에서 월등히 크게 나타났다. The electrocatalytic reduction of O₂ was investigated with methyl viologen and methylene blue incorporated clay-modified electrodes. Clay suspensions were prepared with Namontmorillonite, Ca-montmorillonite, and kaolinite. The methyl viologen-clay modified electrodes were made by coating clay suspensions adsorbing methyl viologen on a glassy carbon electrode. Cyclic voltammetry were performed in aqueous media to investigate the electrocatalytic property of the modified electrode in reducing O₂. A Na-montmorillonite modified electrode showed the greatest adsorption capacity for methyl viologen. The modified electrode made of Na-montmorillonite suspension of 0.87 g/l0 mL and a 2.5 mM of methyl viologen solution showed the most effective electrocatalytic property, where the catalytic reduction potential was shifted by 242.6 ㎷ toward the positive potential. The electrocatalytic ability was more significant in acidic (pH=3.7) and alkaline (pH=12.7) media than the neutral pH range (6.3~8.3). The methyl viologen-Na-montmorillonite modified electrode had the good reproducibility and maintain the electrocatalytic property over 20 times reuse.

시각적 감도를 고려한 영상의 비트량 제어

황재정,오성택 群山大學校 1996 論文集 Vol.23 No.-

Image data is necessary to be reduced to solve the problem of storage media capacity and to efficiently use channel bandwidth for storing and transmiting multimedia data. In this study, we present an image coder using variable quantizer for the JPEG extensions named as ISO/IEC 10918-3 (also as ITU-T Rec. T.84). It is necessary to alleviate the blocking artifact which is more sensitive to human eye in view of the spatial frequency sensitivity and to visually control bit allocation in an image. Since the blocking artifact arises in the lower activity area rather than in the higher area. The block activity is referred to quantize a block and to control buffer status. An image is composed of slices, while a slice is composed of 8 ×8 blocks. Hence we optimize the bit assignment in an image at a given bit rate. As a result of simulation for various images, the proposed coder increases subjective and objective quality.

고압하에서 혼합용매중의 몇가지 염의 전도도

황정의,오상오 慶北大學校 自然科學大學 1987 自然科學論文集 Vol.5 No.-

The equivalent conductance of magnesium chloride and magnesium sulfate soulutions have been measured at different pressures and temperatures varying the solvent composition of components. The conductances of most solutions were increased with increasing pressure but the values of MgCl_2 were decreased in the high alcohol content. The phenomenon indicate that the solvent separated ion effect is predominant in magnesium sulfate solution than in magnesium chloride or sodium chloride which shows the lower conductivities at the higher pressure. The activation energies for the eletrical conductance were remained in constant value of 2∼3 Kcal/mole. The ionization constants of salts were calculated from the conductivity data and physical properties by using the Shedlovsky's equation. The K_d values for magnesium sulfate varied in the range of 1.0×10^-3∼9.0×10^-3 at 20℃. These values are comparable with the values of 1∼10 for sodium chloride at 100℃. These abnormally large values are explained as the results of higher charge and lower temperature effect of magnesium salt than sodium salt. From the concept of the complete ionization constant the hydration number change is also calculated to be 8. 5. This value is slightly different from the sodium chloride.

優先順位를 附與한 ATM 멀티캐스트 스위치의 呼處理 構造에 關한 硏究

황성호,오주현,임해진 三陟大學校 1999 論文集 Vol.32 No.1

An ATM multicast switch which can effectively accommodate diverse classes of traffic, is the core component of broadband ISDN. In this paper, we proposed a new call scheduling algorithm assigning priority according to the quality of service under the diverse traffic environment in multicast switch. The algorithm presented in this paper is using unfairness of switch structure, and delay-sensitive traffic may be given the high priority such that it can be transmitted as soon as possible. Also, we proposed a new hardware structure for the algorithm which can be constructed with combinational logic gates and it is beneficial for high-speed operation and VLSI implementation. The results of simulation for performance evaluation show that mean waiting time of delay-sensitive call is considerably reduced.

한복지의 소비성능에 관한 연구

성수광,권오경,황지영 한국의류학회 1991 한국의류학회지 Vol.15 No.2

In this paper, the fabrics for Korean folk clothes(KFC) undergoes repeated laundering under given condition. After this cyclic laundering was applied, the mechanical properties of the specimen were measured using KES-F system in order to evaluated the end-use performance of fabrics for KFC. And also, the crease recovery of fabrics for KFC were measured by shirley crease recovery tester. 78 different kinds of commercial silk fabrics and polyester fabrics for KFC were used for this study. The experimental results were analysed statistically to relate the mechanical properties and the crease recovery of fabrics for KFC. Furthermore, these changes in dimensional stability, mechanical properties and handle of fabrics for KFC were discussed in comparison with those values for silk fabrics and polyester fabrics. The results obtained are as follows. 1. Regardless of materials, remarkable increase are observed in shrinkage of the fabrics for KFC about repeated laundering, but dull increase are observed in shrinkage after 10 cycles of the repeated laundering. On the other hand, slack extend are observed in dimensions after 20 cycles of the repeated laundering. The shrinkage of fabrics for KFC after 10 cycles of the lundering showed that the silk fabrics are 1.74±0.33% (warp direction) and 1.35±0.23% (weft direction) and the polyester fabrics are 1.45±0.22% (warp direction) and 1.25±0.23% (weft direction). 2. Except for tensile property, these changes in mechanical properties of fabrics for KFC by laundering have ±16 range of bending, shearing, compression, surface, thickness & weight as compared with before laundering. Particularly, the LT and RT about 1∼3 cycles of the repeated laundering showed remarkable decrease. And SMD, WC, T & W of fabrics for KFC by the laundering were more increased than one for original fabrics. But B, 2HB, G, 2HG, 2HG5 were decreased more than one for original fabrics. 3. "Stiffness", "Anti-drape", "Crispness" and "Scroop" hand values decrease and"Fullness & softness", "Flexibility & softness" hand values increase with repeated laundering. 4. Remarkable decrease are observed in crease recoveries about 1∼5 cycles of the repeated lundering, but slack decrease are observed in crease recoveries after 5 cycles of repeated laundering. The crease recovery of fabrics for KFC have negative(-) correlation with LT, RT, G, RC and MMD, This fact implies that the smaller these values, the larger the crease recovery. The crease recovery of fabrics for KFC has a high degree of correlation with the mechanical properties such as shearing, compression, surface property. And also, the crease recovery are expected by measuring the mechanical properties such as G, 2HG, 2HG5, RC, WC, LC, MIU, MMD and SMD, according to the obtained regression equation.