• 상하수도학회지
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• 제24권1호
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• pp.93-101
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• 2010

Reverse osmosis (RO) membranes have been widely used for desalination as well as water and wastewater treatment facilities. Cleaning process is important to maintain stable operation as well as prevention of membrane fouling. Purpose of this research is to analyze electrostatistic and chemical characteristics after cleaning of RO membrane against $SiO_2$ scale. Four RO membranes of polyamide are used and examined about effect of chemical cleaning. EDTA (ethylene diamine tetraacetic acid) and SDS (sodium dodecil sulfate) and NaOH are applied for cleaning process after operation in synthetic water. Then, cleaning was performed with chemicals such concentration as 6hr, 12hr and 24hr, respectively. As a result, transmittances of FT-IR of four membranes are compared at each cleaning concentration. Ta/Tv shows difference of chemical composition between new membrane and cleaning membrane after cleaning. Type B of RO membrane is turned out to be most vulnerable to cleaning among four membranes. In terms of zeta potential, new membrane has -16 mV to +6 mV on pH while scaled membrane has -18 mV to 2 mV. However, it changed -23mV to 0.9 mV after cleaning. In comparison with existing salt rejection of RO membranes after cleaning, the rejection of the membranes goes down 0.7% maximum. Though cleaning changes the characteristics of membrane surface, it does not greatly affect salt rejection. pH is a critical factor to flux change in PA (polyamide) membrane.

• Journal of Preventive Medicine and Public Health
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• 제30권3호
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• pp.518-529
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• 1997

1,281 male subjects who had been examined more than 3 times for regular check-up in one human dock center of the university hospital were studied between 1990-1995, to evaluate the effect of health counselling with life style and $\gamma-GTP$ value between 1054 normal group without intervention and 227 abnormal group with intervention, ages from 30 to 69 years old. Total mean value of $\gamma-GTP$ was $45.7{\pm}40.7$ unit with highest $\gamma-GTP$ value in age group 50-59 on initial examination. Total abnormal rate was 17.7% with the highest abnormal rate of 18.6% in age group 50-59. Initially, the value of $\gamma-GTP$ was significantly different according to the degree of alcohol intake, relative weight and smoking in normal group(p<0.01) not in abnormal group. In conclusion, the value of $\gamma-GTP$ were significantly increasing in normal group without intervention and significantly decreasing in abnormal group with intervention(p<0.05), which suggests the effect of health counselling, such as the recommendation to change the health behaviour.

• 한국지능시스템학회논문지
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• 제19권5호
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• pp.674-682
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• 2009

모듈러 로봇은 기존 이동용 로봇이 가지는 공간 이동의 제한성을 극복하기 위해 개발된 로봇이다. 특히 체인형 로봇은 서로 직렬로 결합이 되어 있어 형체 표현방법이 간단하고 결합방법이 실제로 구현하기가 쉽다. 하지만 모듈러 로봇 관련 연구는 결합을 이용한 움직임 구현에 초접을 두어 독립적인 셀의 움직임은 이루어지지 않으며 모든 면에서 결합하지 못하고 한쪽 방향으로만 결합할 수 있는 등의 문제를 가지고 있다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해서 신속하고 독립적인 이동을 위한 바퀴구조의 모률을 기구에 실장 시켜 스스로의 자율성을 갖게 하였다. 또한 독특한 고정 기어 구조를 적용해 1개의 고정 모터로 2개의 모률을 결합할 수 있게 기구를 설계하여 기구의 효율성을 추구하였다. 이를 위해 본 논문에서는 기구 구조를 제안하고 이를 통작하기 위한 제어 회로에 대한 내용을 다루었으며, 모률간의 결합을 위한 고정 알고리즘과 통신 구조를 설계하였다. 아울러 제작된 프로타입은 실제의 응용예제를 통해 구조의 유용성을 검증하였다.

• 대한조선학회논문집
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• 제46권6호
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• pp.595-602
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• 2009

Great number of ships has been built by Korean Shipyards since early of 2,000 due to the expanding worldwide trade. Most of shipyards have enlarged the weight of erection block and many blocks have been assembled in block fabrication factories outside the shipyards to reduce the shipbuilding period. Especially, Giga blocks that exceed 2,000 tons are often assembled by the block fabrication factories outside the shipyard. Generally, the blocks are transported to building dock in shipyard by towing barges. Accident can be occurred during the sea transportation and it may bring about not only the delay of delivery but also a disaster on the ocean environments. Transportation condition of GPE (Grand Pre-Erection) block differs from the ocean going conditions of marine vessels. Special consideration should be included before transportation work in order to guarantee the safety of GPE blocks and barge carriers. In this paper, several examples, which have been investigated to set up the safety standard of transportation of the GPE blocks on coastal routes, are introduced. For the barge transportation on coastal sea route, the design criteria are discussed, considering the design wave, the acceleration induced by wave, structural strength, and the fixture condition of blocks.

• 한국항만경제학회지
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• 제36권4호
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• pp.75-92
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• 2020

최근의 해운 및 항만 산업에서는 규모의 확대를 통한 경쟁우위의 확보가 주요한 관심이며, 이러한 추세를 반영하여, 국내 항만 및 컨테이너 터미널에서도 부두 통합을 통한 효율성을 강조하고 있다. 본 연구는 항만운영의 가장 작은 단위인 컨테이너 터미널 운영업체 사이의 협력형성 요인을 도출하고 이들의 협력이 컨테이너 터미널 간 어떠한 영향을 미치는지에 대한 효과를 분석하고자 했다. 협력형성 요인들은 자원의 공유, 목적의 명확성, 상호간 신뢰, 정부 정책 영향 등으로 추출되었으며, 또한 효과와 관련한 요인들은 터미널의 운영적 효과, 화주와 선사에 대한 서비스 향상, 정부에 대한 협상력 향상 등으로 나타났다. 실증분석 결과, 이러한 협력 요인들 중 공유성와 목적성은 컨테이너 터미널의 운영적 효과에 영향을 미치며, 자원의 공유는 화주와 선사의 서비스 향상에 영향을 미치는 것으로 나타났다. 마지막으로 정책 요인은 항만 당국 및 대 정부 협상력에 영향을 미치는 것으로 분석되었다.

• Journal of Ginseng Research
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• 제43권2호
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• pp.319-325
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• 2019

Background: Ginsenoside Rf is a ginseng saponin found only in Panax ginseng that affects lipid metabolism. It also has neuroprotective and antiinflammatory properties. We previously showed that Korean Red Ginseng (KRG) inhibited the expression of cyclooxygenase-2 (COX-2) by hypoxia via peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$). The aim of the current study was to evaluate the possibility of ginsenoside Rf as an active ingredient of KRG in the inhibition of hypoxia-induced COX-2 via $PPAR{\gamma}$. Methods: The effects of ginsenoside Rf on the upregulation of COX-2 by hypoxia and its antimigration effects were evaluated in A549 cells. Docking of ginsenoside Rf was performed with the $PPAR{\gamma}$ structure using Surflex-Dock in Sybyl-X 2.1.1. Results: $PPAR{\gamma}$ protein levels and peroxisome proliferator response element promoter activities were promoted by ginsenoside Rf. Inhibition of COX-2 expression by ginsenoside Rf was blocked by the $PPAR{\gamma}-specific$ inhibitor, T0070907. The $PPAR{\gamma}$ inhibitor also blocked the ability of ginsenoside Rf to suppress cell migration under hypoxia. The docking simulation results indicate that ginsenoside Rf binds to the active site of $PPAR{\gamma}$. Conclusions: Our results demonstrate that ginsenoside Rf inhibits hypoxia induced-COX-2 expression and cellular migration, which are dependent on $PPAR{\gamma}$ activation. These results suggest that ginsenoside Rf has an antiinflammatory effect under hypoxic conditions. Moreover, docking analysis of ginsenoside Rf into the active site of $PPAR{\gamma}$ suggests that the compound binds to $PPAR{\gamma}$ in a position similar to that of known agonists.

• Natural Product Sciences
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• 제27권2호
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• pp.99-114
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• 2021

Type 2 diabetes mellitus (T2DM) and its complications are important noncommunicable diseases with high mortality rates. Protein tyrosine phosphatase 1B (PTP1B) and aldose reductase inhibitors are recently approached and advanced for T2DM and its complications therapy. Matricaria chamomilla L. is acknowledged as a worldwide medicinal herb that has many beneficial health effects as well as antidiabetic effects. Our research was designed to determine the most potential antidiabetic phytochemicals from M. chamomilla employing in silico study. 142 phytochemicals were obtained from the databases. The first screening employed iGEMdock and Swiss ADME, involving 93 phytochemicals. Finally, 30 best phytochemicals were docked. Molecular docking and visualization analysis were performed using Avogadro, AutoDock 4.2., and Biovia Discovery Studio 2016. Molecular docking results demonstrate that ligand-protein interaction's binding affinities were -5.16 to -7.54 kcal/mol and -5.30 to -12.10 kcal/mol for PTP1B and aldose reductase protein targets respectively. In silico results demonstrate that M. chamomilla has potential antidiabetic phytochemical compounds for T2DM and its complications. We recommended anthecotulide, quercetin, chlorogenic acid, luteolin, and catechin as antidiabetic agents due to their binding affinities against both PTP1B and aldose reductase protein. Those phytochemicals' significant efficacy and potential as antidiabetic must be investigated in further advanced research.

• The Korean Journal of Pain
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• 제34권3호
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• pp.262-270
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• 2021

Background: Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel implicated in pain sensation in response to heat, protons, and capsaicin (CAPS). It is well established that TRPV1 is involved in mechanical allodynia. This study investigates the effect of Ononis spinosa (Fabaceae) in CAPS-induced mechanical allodynia and its mechanism of action. Methods: Mechanical allodynia was induced by the intraplantar (ipl) injection of 40 ㎍ CAPS into the left hind paw of male Wistar rats. Animals received an ipl injection of 100 ㎍ O. spinosa methanolic leaf extract or 2.5% diclofenac sodium 20 minutes before CAPS injection. Paw withdrawal threshold (PWT) was measured using von Frey filament 30, 90, and 150 minutes after CAPS injection. A molecular docking tool, AutoDock 4.2, was used to study the binding energies and intermolecular interactions between O. spinosa constituents and TRPV1 receptor. Results: The ipsilateral ipl injection of O. spinosa before CAPS injection increased PWT in rats at all time points. O. spinosa decreased mechanical allodynia by 5.35-fold compared to a 3.59-fold decrease produced by diclofenac sodium. The ipsilateral pretreatment with TRPV1 antagonist (300 ㎍ 4-[3-Chloro-2-pyridinyl]-N-[4-[1,1-dimethylethyl] phenyl]-1-piperazinecarboxamide [BCTC]) as well as the β2-adrenoreceptor antagonist (150 ㎍ butoxamine) attenuated the action of O. spinosa. Depending on molecular docking results, the activity of the extract could be attributed to the bindings of campesterol, stigmasterol, and ononin compounds to TRPV1. Conclusions: O. spinosa alleviated CAPS-induced mechanical allodynia through 2 mechanisms: the direct modulation of TRPV1 and the involvement of β2 adrenoreceptor signaling.

• 한국해양공학회지
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• 제36권3호
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• pp.181-193
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• 2022

This study presents a mission management technique that is a key component of underwater docking system used to expand the operating range of autonomous underwater vehicle (AUV). We analyzed the docking scenario and AUV operating environment, defining the feasible initial area (FIA) level, event level, and global path (GP) command to improve the rate of docking success and AUV safety. Non-holonomic constraints, mounted sensor characteristic, AUV and mission state, and AUV behavior were considered. Using AUV and docking station, we conducted experiments on land and at sea. The first test was conducted on land to prevent loss and damage of the AUV and verify stability and interconnection with other algorithms; it performed well in normal and abnormal situations. Subsequently, we attempted to dock under the sea and verified its performance; it also worked well in a sea environment. In this study, we presented the mission management technique and showed its performance. We demonstrated AUV docking with this algorithm and verified that the rate of docking success was higher compared to those obtained in other studies.

• 한국항만학회지
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• 제9권2호
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• pp.39-49
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• 1995

Recently, the traffic volume has been greatly increased partly because of high growth rate of domestic and world economy, and partly because of increased transhipment demand resulting from the destruction of Kobe port by earthqwake early this year. So, container facilities in Pusan Port are under serious congestion. The congestion costs in connection with container traffic in Pusan Port is estimated to be 29.3 billion won in 1994. In 1995 the situation is still worsening. PECT has continued to grow annually by 35% in cargo handling exceeding more than 31% of the total container volumes handled in Korea. The BOR of container berths in PECT in 1994 is 75% reflecting extreme congestion in container traffic. The reason for such serious congestion in PECT is the shortage of container handling facilities in comparison with ever-increasing cargo traffic. In order to solve the provisional problem, the shortage of handling capacity, a model developed to optimize the operation of PECT is described and demonstrated. The model minimizes total port costs, including the costs of dock labour, facilities and equipment, ship, containers, and cargo. The object of this study is, through the model results, mainly to determine the optimal combination of berths and cranes under various circumstances and to show that total costs per ship or unit of cargo served can be reduced by increasing the number of cranes per berth and berth utilization above present levels. Eventually, the results obtained with this model in PECT suggest that increase to 3 in the number of cranes per existing berth could reduce the need for major investments in berths and even reduce operating costs.