폐석분과 폐타이어 칩을 충진제로 한 혼성복합재 (Hycom)의 제조 및 계면현상 연구

황택성,차기식 공주대학교 자원재활용 신소재 연구센터 2002 센터사업 성과집 Vol.- No.1

본 연구에서는 슬러지 및 폐타이어 칩(WTC)으로부터 얻은 폐석분을 충전제로 하고 불포화 폴리에스테르 수지(UPE)를 결합재로 하여 고분자 혼성복합재를 제조하였다. 또한 무기 충전제와 매트릭스 사이의 계면 결합뿐만 아니라 매트릭스 내의 충전제의 분산을 향상시키기 위하여 실란[γ-merthacryloxy propyl trimethoxy silane(γ-MPS)]을 이용하여 표면처리를 하였다. 혼성복합재의 구조적 특성과 기계적 물성에 대한 이 무기 재활용 충전제의 함량과 농도의 영향은 Mercury Porosimeter 및 주사전자현미경을 이용하여 관찰하였다. In this study, wasted stone powders (WSP) obtained from sludge and Wasted Tire Chips (WTC) as fillers have been used to formulate polymer hybrid composites based on Unsaturated Polyester (UPE) resin. To further enhance not only the interfacial bond between the inorganic filler and the polymer matrix, but also the filler dispersion by wetting the particulate surfaces to uniformly spread the resin during the mixing, silane coupling agent[γ-methacryloxy propyl trimethoxy silane (γ-MPS)] was used. The influences of organic recycled fillers contents and the concentrations of coupling agent in polymer hybrid composite formulations have been investigated from a mechanical and microstructural point o view through Mercury Porosimeter and SEM.

무선인터넷 보안 프로토콜 적용방안

이택희 호남대학교 2000 호남대학교 학술논문집 Vol.21 No.2

Wireless data and internet are growing very quickly. But most of the technology developed for the internet has been designed for desktop and large computers. There environment provide wide bandwidth and generally reliable data networks. Wireless Internet is similar to wired internet, but it has some constrained wireless environment. So many internet technologies for wireless are developing now. There are WAP (Wireless Application Protocol) and WPKI. WAP is a protocol specification for wireless communication networks. It provides an application framework and network protocols for wiress devices such as mobile telephones, PDAs(Personal Digital assistants) and internet technologies. In this paper some analysis of security protocol for wireless internet are performed. In the result, better suitable protocol stack design is possible and is easy to implement.

비대칭키 암호체계에 의한 IMT-2000 망의 인증 성능

이택희 호남대학교 1997 호남대학교 학술논문집 Vol.18 No.4

Today, Authentication of digital mobile communication networks is based on the secret key cryptographic technologies. These technologies have merits of processing speed and easy implementation. But they have problems of shared secret key distribution and key database management. Public key cryptosystem can slove these problems and this system is suitable for large scaled system. But its processing algorithm is very slow. In this paper, simplified authentication model is used to check the public key based authentication procedure. This paper analyses the performance of public key based authentication at the view of network load, quality of services, key management, and inter-network authentication .And two types of cryptosystems are compared. As the result, AC for ????? key system needs 10-20 times computing power than that of secret key system. And the size of message to be encrypted should be minimized. Protocol overhead and network delay for public key based authentication is much the same as that of secret key based system, because big portion of network load depends on the authentication message amount. It is not proportional to the cryptographic algorithm speed. Public key management is much easier and key related procedures are much simple. The quality of security is remarkably better than secret key cryptographic algorithm because one key is opened to the public. To support the internetwork authentication in IMT-2000 network, AC should be extended to CA's functions. And crypto system should be based on public key crypto algorithm. In the near future mobile networks would be used to deliver more non-voice and multimedia data than voice traffic. Especially to support the digital signatures and smart card, public key cryptographic procedures are essentially required.

關節可動 範圍 와 柔軟性의 相關性 分析

趙澤九 瑞逸專門大學 1992 論文集 Vol.10 No.-

The purpose of this study is an analysis of Correlation between the range of joint motion and flxibility in Conjunction with upper and lower limbs in 90 Inchon normal person The results are as follow : 1. In Upper limb it showed that closer correlation in elbow than that in shoulder, particulary, in elbow, it was Z-position than that of Y-position that showed significant correlations. 2. In lower limb, it was knee than that of hip that showed significant correlations 3. In whole upper limb it was Z-position right than of its left that showed lots of correlations. 4. In whole lower limb the flexion right, left and the entire of it that showed all reverse correlations. As expceted there was much croorlation between range of joint motion and flexibility but, from now on, it necessary to study separately on sex, age area movement, and muscle strength, etc. The further study will clarify the causes that affect range of joint motion and flexibility.

Grooved pegboard 검사의 정상성인의 표준치에 관한 연구

이택영 한국전문물리치료학회 2001 한국전문물리치료학회지 Vol.8 No.2

Dexterity is defined in the present study as interdigital manipulative skill or the fine manipulative movements of objects held between the thumb and fingers. The Grooved pegboard test has been used to evaluate dexterity requring visual-motor coordination. The purpose of this study was to standardize the completion time of the Grooved pegboard test in different age groups and gender. Normative values for the Grooved Pegboard Test was developed on the sample of 282 healthy volunteers (89 men and 183 women). Subjects were stratified according to gender and dominant hand and were subdivided into six groups by blocking. The results of this study were as follows: 1) There was a significant difference in completion time between dominant and nondominant hand in both men and women groups (p<.05). 2) There were significant differences in completion time between men and women group (p<.05) 3) There were significant differences in completion time among age groups (p<.05).

유아를 위한 레크리에이션

趙澤九 瑞逸大學 1999 論文集 Vol.17 No.-

제주재래마 특이 표지인자 개발

신택순,김선구,강한석,이길왕,조병욱,전해열 密陽産業大學校 農業技術開發硏究所 1998 農業技術開發硏究所報 Vol.2 No.1

본 연구는 제주재래마의 유전적 특성파악과 이를 통한 타품종과의 유전적 특이성을 가지는 DNA 표지인자를 개발하고자 PCR-RAPD기법을 이용하여 제주재래마와 더러브렛, 가고시마의 3품종에서의 다형 band에 대한 특성파악을 실시한 결과이다. 각 품종별로 10두의 혈액을 혼합한 후 분석하였고 200개의 random primer들 중 PCR증폭양상의 재현성을 기준으로 70개의 primer를 선별하였다. 또한 선별된 primer들중 다형성을 9개의 primer를 이용하여 개체별 DNA분석을 실시하였으며 9개의 prkmer에 의해 나타난 15개의 band는 제주재래마 특이 band, 4개는 더러브렛종에 그리고 4개는 가지고시마 재래마에 품종특이 RAPD band가 나타났다. 따라서 RAPD기법에 의해 품종간의 차이를 보이는 표지인자의 개발이 가능할 뿐 아니라 품종간의 특성차이를 보이는 유전인자 개발과 특성파악이 용이한 것으로 평가되었다. This study was carried out using PCR-RAPD technique to estimate genetic characteristics of Cheju Horse (Jorangmal) and to develop the DNA marker for bread identification in horse. Each three horse breeds was represented by pooled DNA from 10 individuals and tested for 200 different random primers for their reproducible PCR pattern. From them 70 primer were selected and 9 primers were used to detect the difference between breeds at the individual level. Fifteen highly polymorphic bands were observed between breeds using 9 primers . Additionally, the 15 most polymorphic bands showed great difference between breeds in their appearing frequencies, implicating their usefulness in the breed discrimination and in the characterization of genetic structure. Therefore, the polymorphism of RAPD could be used in characterizing genomic difference between breeds and some genetic mechanism that give rise to breed disctimination in horse.

차세대 Router 구현 전략

이택희 호남대학교 정보통신연구소 2000 정보통신연구 Vol.10 No.-

The primary role of router is to transfer packets from input links to output links. They must also deal with heterogeneous link technologies, provide scheduling support for differential services and participate in complex distributed algorithms to generate routing tables. These demand complicate their design. The rapid growth of the internet has created different challenges for routers on backbone network and access networks. Here are some analysis for designing the high speed router and active router for next generation internet are performed.

렙틴 수용체가 형질 도입된 신경세포에서 ER Stress로 유도된 렙틴저항성에 대한 일산화탄소의 억제작용

김성주,김택상,류현열,정헌택 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.1

연구 배경 및 목적: 렙틴이 음식의 섭취 양과 체중의 증가를 억제하는 중요한 호르몬 역할을 한다는 사실은 잘 알려졌다. 또한 렙틴에 대한 저항성이 비만의 중요한 원인이라는 연구가 많이 보고되고 있다. 그러나 렙틴 저항성에 대한 구체적인 기전은 아직 밝혀져 있지 않았다. 최근 endoplasmic reticulum (ER) 스트레스에 의한 unfolded protein response (UPR) 가 렙틴에 대한 저항성을 유발한 다는 보고가 있었다. 연구 대상 및 방법: 일산화탄소(carbon monoxide, CO)는 heme oxygenase (HO)-1이 헴(heme)을 산화적 분해로 만들어내는 무색, 무미, 무취의 기체로 항산화, 항염증, 항세포분열 및 항세포고사 작용을 나타내며 조직의 손상에 대한 세포보호작용을 한다. 최근 CO는 ER stress sensor 중의 하나인 protein kinase R-like endoplasmic reticulum kinase (PERK) 를 선택적으로 활성화 시키며 인산화된 PERK 는 HO-1의 전사조절인자인 Nrf2를 인산화로 활성화시켜 결국 HO-1의 유전자 발현을 촉진함이 보고 되였다. 또한 CO로 유도된 PERK의 활성화는 eukaryotic translation initiation factor (eIF) 2a를 인산화로 활성화 시키고 인산화된 eIF2a는 전사인자인 activating transcription factor (ATF)-4의 발현을 유도하지만 CO는 ER stress의 다른 두 개 sensors인 inositol requiring enzyme (IRE) 1a와 하위신호전단물질인 X-box binding protein (xbp)-1이나 ATF6의 활성화에는 영향을 미치지 아니한다. 그러나 ER stress 유발인자들인 thasigargin (TG), tunicamycin (TM), homocysteine 등으로 Xbp-1이나 ATF6가 활성화되는 것을 억제한다. 연구 결과: 본 연구에서는 ER stress 에 의해 활성화되는 UPR에 의해 유발되는 렙틴 저항성이 CO에 의하여 차단될 것이라는 가정을 세우고 다음과 같은 실험결과를 얻었다. TG나 TM에 의해 유도된 ER stress반응 즉 UPR은 렙틴의 신호전달로 야기되는 phospho-signal transducer and activation of transcription (STAT) 3로 인산화되는것을 억제시켰다. 그러나 ER stress를 유도시킬 시 CO를 CO releasing molecule (CORM)으로 처리하였을 때 UPR에 의한 렙틴의 신호전달로 말미암는 STAT3 인산화의 차단이 CO의 양과 노출 시간에 비례하여 제거 되었다. 결론: 이러한 실험결과는 CO에 의한 PERK 인산화는 ER stress 유도체에 의한 IRE1a의 하위 신호전달물질인 Xbp-1 이나 ATF6의 활성화를 억제하여 ER stress 반응인 UPR에 의한 렙틴 저항성을 차단함을 시사한다. 결론적으로 이러한 실험결과는 CO유도체를 이용하여 병인적인 렙틴 저항에 의한 여러 질병을 치료할 수 있음을 시사한다. Background: It is well known that leptin is an important circulating signal for the inhibition of food intake and the gain of body weight. Accumulating data suggest that leptin resistance has been considered to be one of the main causes of obesity. However, the detailed mechanism of leptin resistance is not known yet. Recently, endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) is reported to be responsible for the leptin resistance. Materials & methods: Carbon monoxide (CO), a reaction product of the cytoprotective heme oxygenase (HO)-1, is anti-apoptotic in a variety of models of cellular injury. Exogenous CO activated Nrf2 through the phosphorylation of protein kinase R-like endoplasmic reticulum kinase (PERK), resulting in HO-1 expression. CO-induced activation of PERK was followed by the phosphorylation of eukaryotic translation initiation factor 2a and the expression of activating transcription factor 4. However, CO fails to induce X-box binding protein-1 expression and activating transcription factor 6 cleavage. CO prevented X-box binding protein-1 expression and activating transcription factor 6 cleavage induced by ER-stress inducer such as thasigargin (TG), tunicamycin (TM) and homocysteine. Results: In the present study, we hypothesized that exogenous CO might block the leptin resistance which is induced by UPR during ER stress. Thasigargin or tunicamycin was used to induce ER stress. The activation status of leptin signals were measured by western blotting analysis using a phospho-signal transducer and activation of transcription3 (STAT3) antibody. In this study, ER stress markedly inhibited leptin-induced STAT3 phosphorylation. Conculusion: These results suggest that ER stress induces leptin resistance and exogenous CO-induced phosphorylation of PERK branch reversed ER stress-induced leptin resistance. Moreover, CO releasing molecule (CORM) blocks the inhibition of leptin-induced STAT3 phosphorylation. Together, the pathological mechanism of leptin resistance could be ameliorated by the use of exogenous CO..

모자형 단면부재의 평균 압괴하중

安大植,柳澤仁,韓秉基 弘益大學校 科學技術硏究所 1993 科學技術硏究論文集 Vol.3 No.-

In this study, the mean crushing load of thin-walled closed hat and tube type medel subjected to axial compression is investigated. The energy method for calculating the mean crushing load was based on the Wierzbicki theory for tube section and the Ohkubo theory for single hatted section. And the experiments was performed for comparing with the theoretical results. Among the most important observations and conclusions one may list the following: 1) In the analysis of corner, it is more reasonable to consider the stretching energy by circumferential stretching effect. 2) The difference of energy equations between the tube and the single hatted type model have something to do with the presence of bending energy for flange zone, that is, the equation of the single hatted type model is equal to the equation that added the bending energy in flange zone to the tube type model. 3) In the case of double hatted section member, the stretching energy of corner met with flange as well as the bending energy of flange must be added. Also crash modes of double hatted section member was more complicated and one need more investigation about these.