아라미드 표면처리에 의한 실리콘/불소 고무와의 접착성 연구

이재호,이재동,박성민,이종우,Lee, Jae-Ho,Lee, Jae-dong,Park, Sung-min,Lee, Jong-woo 한국섬유공학회 2018 한국섬유공학회지 Vol.55 No.5

The interfacial adhesion property between aramid and rubber is a very important factor when aramid is applied as a reinforcing material for automotive heat-resistant hoses. This study examined the improvement of interfacial adhesion between aramid and rubber by applying plasma and a coupling agent to m-aramid. The SEM, AFM, and XPS characteristics were examined based on the plasma treatment conditions. The plasmatreated aramid was then treated with the coupling agent to analyze the interfacial adhesion with silicon, fluorine, and hybrid rubber. The plasma treatment resulted in an increase in the surface roughness of the aramid, and the mechanical properties of the aramid fabric decreased because the surface of the aramid was fibrillated. Moreover, the interfacial adhesion between aramid and rubber increased by 16.2% with the use of the coupling agent and plasma treatment.

WiBro 환경에서 Overlay 기반의 Mobile IPv6 이동성 구현 및 성능 시험에 관한 연구

이재호,류형근,이재준,강선무,이재용,Lee, Jae-Ho,Ryu, Hyung-Keun,Lee, Jae-Jun,Kang, Sun-Moo,Lee, Jai-Yong 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.6b

A Mobile IP is considered for the efficient mobility function in IEEE 802.16/WiBro environment. However, during the deployment of WiBro, only some of the ACRs(Access Control Router) can support the Mobile IP function. Therefore, a WiBro network can not support the mobility function for the mobile node. In this paper, we implement an overlay-based Mobile IP function and measure the performance through a field trial. Moreover, we evaluate the possibility of commercial deployment and suggest areas that need to be improved. IEEE 802.16/WiBro 환경에서 효율적인 이동성을 위하여 Mobile IP 적용이 고려되고 있다. 하지만 WiBro 확산과정에서 Mobile IP 이동성을 지원하는 ACR과 지원하지 못하는 ACR이 혼재된 상황이 존재하고 있으며, 이럴 경우 단말의 이동성은 보장받기 어렵게 된다. 본 논문에서는 이러한 WiBro 환경에서 지속적인 단말 이동성을 지원하기 위하여 Overlay 기반의 Mobile IP 이동성을 실제로 구현하고 이에 대한 성능 시험을 시행한 후 현장 적용 가능성을 검증하고 향후 개선 필요 사항을 도출하였다.

분산염색에서 Cotelomer 타입 계면 활성제의 응용

이재호,최해욱,정영진,황대연,최영호,이언필,Lee, Jae-Ho,Choi, Hae-Wook,Jung, Young-Jin,Hwang, Dae-Youn,Choi, Young-Ho,Lee, Eon-Pil 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.1

Multi-chain surfactants usually form micelles more easily than single-chain surfactants due to their low surface tension and low solubility in water. In this study we prepared cotelomers of multi-alkylated nonionic surfactants with a molecular structure $xR_nMA$-yVA (x; hydrophobic group, y; hydrophilic group, MA; methacrylic ester, VA; vinyl alcohol, R; alkyl group) and investigated their properties as surfactants for the disperse dyeing of cellulose acetate, nylon 6, and PET fibers. Some cotelomers were synthesized via a radical polymerization of vinyl monomers MA and VA using azobisisobutyronitrile (AIBN) as an initiator. The ratio of x/y and degree of polymerization of $xR_nMA$-yVA with an alkyl chain length (n) of 4 or 6 were controlled by adjusting the ratio of thiol to monomers. We found that a cotelomer with a degree of polymerization 9.9 showed better dispersing performances than cotelomer with a degree of polymerization 4.4 or 12.5, and that the degree of dispersion increased to a certain level and then decreased as concentration of cotelomer increased. The highest value of dye uptake for the three fibers was obtained when using a cotelomer with a monomer unit ratio (x/y) of 0.2 and 0.5 g/l of concentration was 0.5 g/l.

T-형 $Ca^{2+}$ 채널 길항제인 Mibefradil을 첨가한 인간 정자의 첨체반응 관찰

이재호,손원영,이정하,이인선,김영찬,한징택,Lee, Jae-Ho,Son, Weon-Young,Lee, Jung-Ha,Lee, In-Sun,Kim, Young-Chan,Han, Ching-Tack 대한생식의학회 2000 Clinical and Experimental Reproductive Medicine Vol.27 No.1

Objective: The sperm acrosome reaction is a $Ca^{2+}$-dependent exocytotic event that is triggered by adhesion to the mammalian egg's zona pellucida. Previous studies suggested a role of $Ca^{2+}$ channels in acrosome reactions. This study was conducted to investigate the T-type calcium channel is operated in acrosome reaction of human spermatozoa. Method: Human semen samples were obtained from healthy donors with normal criteria. The spermatozoa were divided into five groups: Group 1 were non-treated as a control; Group 2 where spermatozoa were exposed to 5 ${\mu}M$ $Ca^{2+}$ A23187 $(Ca^{2+}i)$; Group 3 where spermatozoa were exposed 5 ${\mu}M$ $Ca^{2+}i$ and mibefradil; Group 4 where spermatozoa were exposed 5 ${\mu}M$ $Ca^{2+}i$ and nifedipine, and Group 5 where spermatozoa were treated with 5 ${\mu}M$ $Ca^{2+}i$ and both of mibefradil and nifedipine. Spermatozoa in all groups were retrieved after incubation for 15 and 30 minutes at $37^{\circ}C$. After staining with PSA-FITC, fluorescence was observed under a fluorescence microscope, and AR was evaluated on a total>100 spermatozoa/side. Result and Conclusion: We observed on acrosome reaction inhibition rate in human spermatozoa the various of concentration of mibefradil, nifedipine. Maximum response was noted with 1.0 ${\mu}M$ mibefradil and the decrease of acrosome reaction inhibition rate 45%. Nifedipine in acrosome reaction inhibition rate was only about 25%. The $Ca^{2+}i$-induced AR of spermatozoa was significantly suppressed by mibefradil. Incidence of the suppression was depending on concentration of mibefradil. Results from the present study suggest that the human spermatozoa possess T-type channel. The observation that reversible inhibitor of T channels in male germ cells provides a new mechanism of contraceptive action.

Flash EEPROM에서 부유게이트의 도핑 농도가 소거 특성에 미치는 영향

이재호,신봉조,박근형,이재봉,Lee, Jae-Ho,Shin, Bong-Jo,Park, Keun-Hyung,Lee, Jae-Bong 대한전자공학회 1999 電子工學會論文誌, D Vol.d36 No.11

Flash EEPROM에서 칩 전체나 또는 칩의 한 블록에 속에 있는 모든 셀들의 소거는 Fowler-Nordheim (FN) 터널링 방식을 사용하여 일괄적으로 수행되고 있다. 이러한 FN 터널링에 의한 소거는 self-limited 공정이 아니기 때문에 일부의 셀들이 심하게 과소거되는 문제가 자주 발생하고 있다. 본 논문에서는 이러한 과소거 문제를 해결하기 위한 부유게이트의 최적 도핑 농도에 관하여 연구하였다. 이러한 연구를 위하여 다양한 도핑 농도를 갖는 n-type MOSFET과 MOS 커패시터를 제작하였고, 이 소자들의 전기적인 특성들을 측정 및 분석하였다. 실험 결과, 부유게이트의 도핑 농도가 충분히 낮다면 ($1.3{\times}10^{18}/cm^3$ 이하) 과소거가 방지될 수 있음을 볼 수 있었다. 이는, 소거시 부유게이트에 저장되었던 전자들의 대부분이 빠져나가면 부유게이트에 공핍층이 형성되어 부유게이트와 소스 사이의 전압 차가 감소하고 따라서 소거가 자동적으로 멈추기 때문이라고 판단된다. 반면에 부유게이트의 도핑 농도가 너무 낮을 경우 ($1.3{\times}10^{17}/cm^3$ 이하)에는 문턱 전압과 gm의 균일도가 크게 나빠졌는데, 이는 부유게이트에서 segregation으로 인한 불순물의 불균일한 손실에 의한 것이로 판단된다. 결론적으로 Flash EEPROM에서 과소거 현상을 방지하고 균일한 문턱 전압과 gm을 갖기 위한 최적의 부유게이트의 도핑 농도는 $1.3{\times}10^{17}/cm^3$에서 $1.3{\times}10^{18}/cm^3$의 범위인 것으로 발견되었다. All the cells on the whole memory array or a block of the memory array in the Flash EEPROM's are erased at the same time using Fowler-Nordheim (FN) tunneling. some of the cels are often overerased since the tunneling is not a self-limited process. In this paper, the optimum doping concentration of the floating gate solve the overerase problem has been studied. For these studies, N-type MOSFETs and MOS capacitors with various doping concentrations of the gate polysilicon have been fabricated and their electrical characteristics have been measured and analyzed. As the results of the experiment, it has been found that the overerase problem can be prevented if the doping concentration of the floating gate is low enough (i.e. below $1.3{\times}10^{18}/cm^3$). It is because the potential difference between the floating gate and the source is lowered due to the formation of the depletion layer in the floating gate and thus the erasing operation stops by itself after most of the electrons stored in the floating gate are extracted. On the other hand, the uniformity of the Vt and the gm has been significantly poor if the coping concentration of the floating, gate is too much lowered (i.e. below $1.3{\times}10^{17}/cm^3$), which is believed to be due to nonuniform loss of the dopants from the nonuniform segregation in the floating gate. Consequently, the optimum doping concentration of the floating gate to suppress the overerase problem and get the uniform Vt and has been found to range from $1.3{\times}10^{17}/cm^3$ to $1.3{\times}10^{18}/cm^3$ in the Flash EEPROM.

수표교(水標橋) 칼럼 - 독일에서 배우는 탈원전과 신재생에너지

이재호,Lee, Jae-Ho 대한전기협회 2013 전기저널 Vol.- No.436

우리나라 가정간호의 바람직한 방향

이재호,Lee, Jae-Ho 한국가톨릭의료협회 2004 Health & mission Vol.2 No.-

우리 주위엔 병ㆍ의원에 가고 싶어도 가지 못하거나 방치되고 있는 환자들이 많다. 현재의 가정간호제도를 진단하고 선진국과 비교해 봄으로써 바람직한 정책 방향을 제시하고자 한다.

수종 치조제 이물성형재의 조직반응에 관한 연구

이재호,김영수,Lee, Jae-Ho,Kim, Yung-Soo 대한치과보철학회 1989 대한치과보철학회지 Vol.27 No.1

Loss of teeth causes the inevitable reduction of residual ridge. Among the various methods solving this problem, hydroxyapatite proved to be useful for correction of ridge defect and irregularity. The purpose of this study is to evaluate the tissue responses of two types Of hydroxyapatites and resin polymer. Calcitite 2040 (Calcitek Inc.), Interpore 200 (Interpore Int.), and HTR polymer (HTR Sciences) were implanted into the jaw of an adult dog. The procedure was designed to obtain the results of 1 week, 2 week, 4 week, and 12 week-intervals. And after 12 weeks from the first operation day, the dog was sacrificed and evaluated histologically by light microscope. The results were as follows : 1. The mucosa was healed after two weeks. 2. After 1 week, there were acute inflammatory cells, but diminished after 2 weeks and were not seen after 12 weeks. 3. The hydroxyapatites implanted in soft tissues were surrounded by fibrous connective tissue. And some foreign body giant cells were found. 4. Calcitite and Interpore particles implanted subperiosteally were surrounded by newly formed bone after 12 months. And direct contact between bone and particles was noted. 5. The HTR particles implanted in soft tissues were encapsulated by fibrous connective tissues. The sample where the particles contacted directly to bone could not obtained by some probable insufficiencies of surgical technique or care of the animal. And the residue of HTR particles was digested by macrophage.

2014년과 2020년 양주시 도시공원 이용빈도별 집단 간 이용행태 및 인식차이 연구

이재호,Lee, Jae Ho 한국조경학회 2021 韓國造景學會誌 Vol.49 No.2

본 연구는 도시공원을 이용하는 시민을 대상으로 이용빈도에 따라 이용자를 분류하여 도시공원 이용 시 이용행태, 관리방안 및 인식 차이를 보고자 하였으며, 동일한 설문지를 사용한 2014년도와 2020년도 설문조사 결과를 이용하여 도시공원 운영 및 관리에 대한 시사점을 제시하고자 하였다. 경기도 양주시의 도시공원을 대상으로 연구를 진행하였으며, 양주시에 거주하는 시민을 대상으로 2014년에는 740부, 2020년에는 431부의 설문지 결과를 이용하였다. 공원 이용빈도에 따라 고이용, 저이용 집단으로 분류하고, 집단에 따른 인구사회학적 차이 및 공원이용방식 차이를 비교한 후, 두 집단 간에 향후 공원 관리방향에 대한 인식 차이를 해당 연도에 따라 통계적 분석기법을 활용하여 분석 및 비교하였다. 분석결과, 2014년도에는 공원의 양적 확충 및 접근성 개선이 가장 주요한 문제로 두드러졌지만, 2020년에는 양적 확대보다는 노후 시설 점검 및 개선, 다양한 프로그램 제공, 지역의 정체성을 드러낼 수 있는 테마형 근린공원 조성 등 공원운영 관리방안에 대한 관심이 높아졌음을 확인할 수 있었다. 공원관리 방향의 차이에 있어서는 고이용 집단에서 지속적 관리가 중요하다고 인식하고 있음에도 불구하고, 덜 이용하는 집단에 비해서 상대적으로 소극적으로 공원개선 활동에 참가하겠다고 응답하였으며, 이는 장기적으로 공원을 더 많이 이용하는 사람들을 어떠한 방식으로 공원관리에 참여시킬 수 있는지에 대한 논의가 필요함을 보여주었다. 본 연구는 이용빈도에 따라 이용집단을 나눠서 다른 행태 및 인식 차이를 보고자 했다는 점에서 의의가 있지만, 향후 연구에서는 다양한 변수의 조합을 통해 보다 세밀한 이용집단의 차이를 분석할 필요가 있다. This study was conducted to see the differences of park users by classifying them with their park use frequency in terms of park use, management policy and perception, using the same survey results conducted in 2014 and 2020. Research was conducted on urban parks in Yangju, South Korea, and 740 in 2014 and 431 in 2000 survey results were used. After classifying the high-use and low-use groups according to park use frequency, this study compared the demographic differences and park use method differences according to the group, the recognition differences for the future park management direction between the two groups were analyzed and compared using statistical analysis by year. The results showed that the park's quantitative expansion and accessibility improvements were the most important issues in 2014, while the importance of park management, such as checking and improving aging facilities, providing various programs, and creating a themed neighborhood park that could reveal the identity of the area, was increased in 2020. Despite recognizing the importance of persistent management in the case of high-use groups, the results showed that they were less willing to participate in park management programs compared to less-use groups, which showed the need for a discussion of how to involve high-use groups for long term park management. This study contribute the body of literature that it seeks to understand differences of park user in terms of their park use frequency. However, in future studies, analyzing the differences of park users through a short-term study is required.

파킨슨병 환자의 경직에 대한 임상적 평가의 정량화

이재호,김지원,권유리,엄광문,고성범,김형식,이정한,이정환,Lee, Jae-Ho,Kim, Ji-Won,Kwon, Yu-Ri,Eom, Gwang-Moon,Koh, Seong-Beom,Kim, Hyung-Sik,Yi, Jeong-Han,Lee, Jeong-Whan 대한의용생체공학회 2010 의공학회지 Vol.31 No.4

The purpose of this study was to quantify the clinical assessment of rigidity at wrist in patients with Parkinson's disease. The experimental system was designed that the effect of gravity was negated by restricting motion at the horizontal plane and inertia was predetermined from a biomechanical measurement. Forty five patients with Parkinson's disease participated in this study. Viscoelastic properties were calculated from the experimental data acquired during intermittent passive movement of wrist. Viscoelastic constants correlated well with the rigidity scores of UPDRS, i.e., Spearman's r=0.733 and 0.905 for spring and damping constants, respectively. The results suggest that viscoelastic properties can be used as quantitative measures of rigidity.