Geotextile Filter의 특수성능 분석

權武南,李相昊,金勝勳 慶北大學校 1992 論文集 Vol.52 No.-

In order to lock stability of geotextile filer to clogging or blocking, small scale laboratory tests were accomplished, considering to drainage conditions, on domestic and foreign nonwoven geotextile products used for filter, and permeable capacity of the geotextile filter was analyzed. The results obtained are as follows: 1. The permeable flow rate through the geotextile filter appears to be decrease remarkably in the initial stage of duration time but gradually afterward and is stabilized at 300 hours∼400 hours of duration time. 2. The increase ratio of permeable flow rate through the geotextile filter due to rising hydraulic head appears to be higher with protected soil having lower comparative content of fine particles, and the effect of rising hydraulic head finds to be higher with that protected soil. 3. The permeable flow rate through the geotextile filter appears to be higher with protected soil having lower content of fine particles and the increase of it trends to be considerable and to be decrease according to the elapse of time. From the fact, the flow rate finds to be more influenced by clogging or blocking with protected soil layer having lower content of fine particles. 4. It seems generally that the thicker the geotextile filter is, the higher the permeable flow rate is, but the decrease ratio of it in the initial stage finds to be lower in the case of thicker geotextile.

An Analysis of the Performance of the “1/N” Naïve Portfolio Strategy in Korean Stock Markets

Sang-Hoon Le,Jihun Kim 사람과세계경영학회 2018 Global Business and Finance Review Vol.23 No.4

In this study, we compare three measurements of 12 asset-allocation strategies to a “1/N” portfolio using historical data of Korean stock markets, which is a representative emerging market, from January 2000 to December 2015. We find that in Korean stock markets the asset allocation strategies with short sale constraint have better performance than the “1/N” portfolio (i.e., high Sharpe ratios and high certainty-equivalent returns). While these optimal asset-allocation models have higher turnover than the “1/N” portfolio, the Sharpe ratio of short sale constraint is still higher than the “1/N” portfolio when we consider transaction costs. The results are surprising because no asset-allocation strategies are consistently dominant on “1/N” portfolio using US stock market data.

단순정맥압박검사에 의한 혈액내 FDP ( fibrinogen degradation produc ) 농도 변화를 이용한 인슐린비의존성 당뇨병환자와 뇌졸중환자의 대혈관기능 이상 진단

김상훈(Sang Hoon Kim),심성춘(Sung Chun Sim),장남수(Nam Soo Jang),박창영(Chang Young Park),최윤상(Young Sang Choi),이규백(Kyu Beck Lee),강진호(Jin Ho Kang),김향(Hang Kim),조윤경(Yoon Kyung Cho),김유리(Yoo Lee Kim),이상종(Sang Jong Le 대한내과학회 1999 대한내과학회지 Vol.56 No.5

N/A Objectives : In diabetic patients, the incidence of atherosclerotic disease are increased, which may be due to decreased fibrinolytic activity. The aim of study is to elucidate the relationship between angiopathies and vascular function evaluated by simplified venous occlusion test in patients with non-insulin dependent diabetes mellitus (NIDDM) and cerebrovascular accident (CVA). Methods : The study was conducted on 63 patients who were hospitalized during the period from March 1, 1994 to May 30, 1997. The serum concentration of fibrinogen degradation products (FDP) was measured before and 5 min after venous occlusion in 31 NIDDM patients, 16 CVA patients and 16 age-matched control subjects. FDP was measured with the anti-fibrinogen- coated latex particle agglutinin assay system. Results : 1) The basal serum FDP level was higher in diabetic patients with macroangiopathy (12.3±5.8 ug/ml) and patients with CVA (11.2±5.1 ug/ml) than in control subjects (5.7±1.8 ug/ml) (p<0.05). 2) The increment of serum FDP level after venous occlusion in diabetic patients with microangiopathy (6.6±2.2 to 10.3±4.1 ug/ml) and control subjects (5.7±1.8 to 11.4±4.3 ug/ml) was significantly higher than basal serum FDP level (p<0.05). But the increment of serum FDP level after venous occlusion in diabetic patients with macroangiopathy (12.3±5.8 to 15.2±5.1 ug/ml) and patients with CVA (11.2±5.1 to 13.7±4.8 ug/ml) wasn't significantly higher than basal serum FDP level. 3) The increment rate of serum FDP after venous occlusion in diabetic patients with macroangiopathy (24.4±29.3%) and patients with CVA (29.4±34.5%) was significantly lower than diabetic patients with microangiopathy (66.3±71.7%) and control subjects (84.1±69.3%) (p<0.05). Conclusion : The responsiveness of fibrinolytic activity to venous occlusion was significantly lower in diabetic patients with macroangiopathy, as in patients with CVA, compared with that in control subjects. We conclude that measurement of the increase in serum FDP concentration 5 min after venous occlusion may be useful to detect vascular dysfunction in patients with macrovascular disease caused by atherosclerosis.

A Study on Weighing the Critical Factors of Building a New Deep Seaport System : the Case of Lach Huyen, Vietnam

Le-Quoc Loi,Sung-Hoon Park,Gi-Tae Yeo 한국항해항만학회 2021 한국항해항만학회지 Vol.45 No.2

The aim of this study is to determine the critical factors and construction requirements for a new deep-water seaport system in the Lach Huyen area in northern Vietnam. In this study, the Analytic Hierarchical Process (AHP) method was used to evaluate the importance of the criteria and subcriteria. The results were as follows: the principal criterion “geographical location (0.151)” ranked as the most important criterion for building a new deep-water port system, which is affected by the subcriteria “direct sea route with mega-vessel” and “good liner connectivity index”. The principal criterion “port competency (0.145)” ranked second; thus, it can be concluded that good competitiveness of a port’ will provide many benefits to the port and the region. Regarding the implication, the established evaluation framework can be used for port construction to make a more reasonable judgment. In a future study, the scope of evaluation factors should be widened, involving participation of broader stakeholders, such as shipping companies, forwarders, and logistics companies.

A SMA-based actuation system for a fish robot

Le, Chan Hoang,Nguyen, Quang Sang,Park, Hoon Cheol Techno-Press 2012 Smart Structures and Systems, An International Jou Vol.10 No.6

We design and test a shape memory alloy (SMA)-based actuation system that can be used to propel a fish robot. The actuator in the system is composed of a 0.1 mm diameter SMA wire, a 0.5 mm-thick glass/epoxy composite strip, and a fixture frame. The SMA wire is installed in a pre-bent composite strip that provides initial tension to the SMA wire. The actuator can produce a blocking force of about 200 gram force (gf) and displacement of 3.5 mm at the center of the glass/epoxy strip for an 8 V application. The bending motion of the actuator is converted into the tail-beat motion of a fish robot through a linkage system. The fish robot is evaluated by measuring the tail-beat angle, swimming speed, and thrust produced by the tail-beat motion. The tail-beat angle is about $20^{\circ}$, the maximum swimming speed is about 1.6 cm/s, and the measured average thrust is about 0.4 gf when the fish robot is operated at 0.9 Hz.

Pharmacokinetic study comparing pure desoxo-narchinol A and nardosinonediol with extracts from <i>Nardostachys jatamansi</i>

Le, Vu Ngoc Han,Zhao, Yan,Cho, Chong Woon,Na, MinKyun,Quan, Khong Trong,Kim, Jang Hoon,Hwang, Sung Yeoun,Kim, Sang Wook,Kim, Kyung Tae,Kang, Jong Seong Elsevier 2018 Journal of chromatography. B, Analytical technolog Vol.1102 No.-

<P><B>Abstract</B></P> <P>Nardostachyos Radix et Rhizoma (NR) is a valuable medicinal herb widely used in Korea, India, and China for the treatment of many diseases. Desoxo-narchinol A (DA) and nardosinonediol (ND) are the two main bioactive compounds belonging to the sesquiterpene group. Desoxo-narchinol A possesses anti-inflammatory activity while ND exhibits anti-depressant and cardioprotective activities. A pharmacokinetic study is important to decide whether the isolated compounds or the NR extract have better pharmacological activity. Hence, we developed an analytical method for studying the pharmacokinetics of DA and ND after oral administration of the pure compounds and herbal extract. An optimized liquid chromatography-mass spectrometry method (LC-MS/MS) with solid-phase extraction (SPE) for sample preparation was developed. A ZORBAX Extend C18 column (2.1 × 50 mm, 3.5 μm) was used under gradient elution with acetonitrile and 0.1% formic acid in water as the mobile phase. Validation experiments assessing accuracy, precision, and stability were satisfactory; the lower limit of quantification was 5 ng/mL. For the pharmacokinetic study, three groups of rats were administrated pure DA, pure ND, or NR extract orally. Concentrations of DA and ND in their plasma were determined by the developed method. Pharmacokinetic parameters, including the time to achieve maximum plasma concentration (<I>T</I> <SUB> <I>max</I> </SUB>) and the area under the plasma concentration curve from time zero to infinity (<I>AUC</I> <SUB>0–∞</SUB>), were compared for the herbal extract and pure compounds. The <I>T</I> <SUB> <I>max</I> </SUB> of the pure compound and the NR extract for DA was 7.50 and 8.33 min, respectively, compared to 5.00 and 5.83 min for the pure compound and the NR extract for ND, respectively. The <I>AUC</I> <SUB>0–∞</SUB> of the pure compound and the NR extract for DA was 156.34 and 133.90 μg min/mL, respectively, and that for the NR extract for ND was 6.42 and 4.15 μg min/mL, respectively. LC-MS/MS was used to determine DA and ND in rat plasma. The pharmacokinetic profile of each pure compound and those in the extract were characterized and compared.</P>

수처리용 생태모방 촉매/여과 복합 필터의 성능 평가

Le Thi Thao,최승원(Seung Won Choi),Que Thi Nguyen,서진영(Jin Young Suh),조상호(Sang Ho Cho),백경열(Kyung-Ryul Baek),김기팔(Ki-Pal Kim),김상훈(Sang Hoon Kim) 유기성자원학회 2023 유기성자원학회 학술발표대회논문집 Vol.2023 No.1

Bioinspired pH- and Temperature-Responsive Injectable Adhesive Hydrogels with Polyplexes Promotes Skin Wound Healing

Le, Thai Minh Duy,Duong, Huu Thuy Trang,Thambi, Thavasyappan,Giang Phan, V.H.,Jeong, Ji Hoon,Lee, Doo Sung American Chemical Society 2018 Biomacromolecules Vol.19 No.8

<P>Despite great potential, the delivery of genetic materials into cells or tissues of interest remains challenging owing to their susceptibility to nuclease degradation, lack of permeability to the cell membrane, and short in vivo half-life, which severely restrict their widespread use in therapeutics. To surmount these shortcomings, we developed a bioinspired in situ-forming pH- and temperature-sensitive injectable hydrogel depot that could control the delivery of DNA-bearing polyplexes for versatile biomedical applications. A series of multiblock copolymer, comprised of water-soluble poly(ethylene glycol) (PEG) and pH- and temperature-responsive poly(sulfamethazine ester urethane) (PSMEU), has been synthesized as in situ-forming injectable hydrogelators. The free-flowing PEG-PSMEU copolymer sols at high pH and room temperature (pH 8.5, 23 °C) were transformed to stable gel at the body condition (pH 7.4, 37 °C). Physical and mechanical properties of hydrogels, including their degradation rate and viscosity, are elegantly controlled by varying the composition of urethane ester units. Subcutaneous administration of free-flowing PEG-PSMEU copolymer sols to the dorsal region of Sprague-Dawley rats instantly formed hydrogel depot. The degradation of the hydrogel depot was slow at the beginning and found to be bioresorbable after two months. Cationic protein or DNA-bearing polyplex-loaded PEG-PSMEU copolymer sols formed stable gel and controlled its release over 10 days in vivo. Owing to the presence of urethane linkages, the PEG-PSMEU possesses excellent adhesion strength to wide range of surfaces including glass, plastic, and fresh organs. More importantly, the hydrogels effectively adhered on human skin and peeled easily without eliciting an inflammatory response. Subcutaneous implantation of PEG-PSMEU copolymer sols effectively sealed the ruptured skin, which accelerated the wound healing process as observed by the skin appendage morphogenesis. The bioinspired in situ-forming pH- and temperature-sensitive injectable adhesive hydrogel may provide a promising platform for myriad biomedical applications as controlled delivery vehicle, adhesive, and tissue regeneration.</P> [FIG OMISSION]</BR>

Disorders of Small and Large Intestine : Relation Beetween Gastrointestinal Symptoms And Colonoscopic Findings In The Intestinal Behcet`s Disease

( Sung Hee Jung ),( Yun Jung Lee ),( Sung Hoon Lee ),( Hyang Le Lee ),( Hyeon Woong Yang ),( An Na Kim ),( Sang Woo Cha ) 대한소화기학회 2007 SIDDS Vol.9 No.-

Background/Alms: The frequency of intestinal involvement in Behcet`s disease is known to be 3~25% with geographic differences which is higher in East Asian patients including Koreans. We tried to find out the reliable gastrointestinal symptoms and laboratory data which can predict the verification of intestinal Behcet`s disease by colonoscopy. Methods: Between April 2004 and August 2007, 29 patients underwent colonoscopy among 186 patients who were diagnosed with complete or incomplete type Behcet`s disease at the department of rheumatology internal medicine, Eulji medical school hospital, Daejeon, Korea. We analyzed the relations among their symptoms, colonoscopic findings, and laboratory data, retrospectively using medical records. A p value of less than 0.05 was considered as statistically significant. Results: The mean age of the 29 patients was 43.3 years; most (23/29) of them were female. Twenty two (75.9%) patients complained of gastrointestinal symptoms, such as abdominal pain (41.1%), hematochezia, diarrhea, loose stool. On laboratory examination, mean Hb was 12.3 g/dL, ESR 31.8 mm/hr, and CRP 2.30 mg/dL. On colonoscopy, lesions were found in only 50% of the symptomatic patients. There was no significant relation with the presence of gastrointestinal symptoms and colonoscopic lesions (p>0.05). Hematochezia (p=0.004) and anemia (p=0.042) were strongly correlated to colonoscopic lesions unlike diarrhea, loose stool, abdominal pain, ESR, and CRP elevation Conclusions: We should consider the colonoscopic examination including terminal ileum to the Behcet`s disease patients who showed hematochezia and anemia for the early recognition of intestinal Behcet`s disease.

Evaluation of biological effects of ion beam irradiation in pepper (Capsicumannuum L.)

Sang Hoon Kim,Yeong Deuk Jo,Hyo-Jeong Lee,Yu-Mi Lee,Si-Yong Kang 한국육종학회 2014 한국육종학회 심포지엄 Vol.2014 No.07

Radiation technologies have been widely used in mutation breeding of crops. Although gamma-radiation has been predominantly applied in radiation breeding, ion beam irradiation is recently emerging as a methodology highly effective in induction of mutations that are useful for plant breeding. Therefore, we investigated the biological effects caused by irradiation of two types of ion beams, which were proton and ion beams, respectively, in pepper. In the evaluation of survival rate, LD50 values were between 300 and 350 Gy, 30 and 40 Gy in irradiation of proton and carbon beams, respectively, while LD50 for gamma-ray was determined to be between 50 and 100 Gy. Growth traits including shoot length, root length, and root width were also examined in pepper seedlings according to does of proton and carbon ion beams to estimate biological effectiveness of each radiation. The result was applied in the construction of pepper mutant population which will be used to develop pepper breeding materials containing novel characteristics.