• Journal of the Korean Electrochemical Society
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• v.18 no.1
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• pp.17-23
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• 2015

$Li_4Ti_5O_{12}$ (LTO) have attracted much attention of researchers in the field of energy storage, because of their excellent stability for electric vehicle application. A main drawback of LTO is however their insulating nature due to the wide bandgap, which should be addressed to enhance the battery performance. In this study, we investigated the effect of water solubility of dopant precursor on the electrochemical characteristics of conducting LTO prepared by doping with $Cr^{3+}$ ions with the well-known wet-mixing method. The solubility of dopant precursor directly affected the morphology and the phase of doped LTO, and therefore their battery performance. In the case of employing the most soluble dopant precursor, $Cr(NO_3)_2$, the doped LTO demonstrated a markedly enhanced discharge capacity at high C-rate (130mAh/g @ 10C), which is about 2 times higher value than that of bare LTO.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.61-69
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• 2016

Since 2000, the market of convenient stores in Korea has developed rapidly due to the explosive growth in single households but it still consists mainly of manual work due to the nature of the domestic industry. Hence the explosive increase in demand in the market is mostly due to workers. Therefore, the research aimed at encouraging efficiency via automation, which is carried out in manufacturing, such as electronic, cars and so on, is inadequate. This study performed a feasibility analysis of investment for introducing an automated system on brand A, which is domestic famous convenience store company. Productivity growth according to the introduction of an automated guided vehicle and the cost-benefits was studied with using a simulation for the picking process, which is most personnel and time consuming. As a result, the simulation showed that the equipment AGV introduced for choosing the process has the effects of cost saving and increased time efficiency for performing manual labor. Furthermore, appropriate numbers of AGV were forecasted considering the capacity of the distribution Center in the brand A convenient store, which has been growing steadily. There are increasing numbers of worker labor costs in the distribution industry these days. Before building a large new automate center, it is expected to provide a good information to investors who are considering increasing productivity through partial automation of each of unit process to achieve some cost reduction.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.375-383
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• 2009

The aims of this study were wintering individuals, usage of foraging sites, potential food availability, daily activity and disturbance factors of White-naped Cranes Grus vipio on the wintering site, Han-river estuary, Goyang and Gimpo city, Korea. We want to provide basic data to conserve the cranes. Maxium population was identified 162 individuals at the middle of February in the river side and mud flat of this study area. Spring migration for breeding was started at the first week of March and finished for two weeks later. White-naped Cranes were used four feeding sites in winter; agricultural area in Hongdopyong, Yihwa-dong, Pyong-dong and Songpo-dong. Expected carrying capacity (ECC) was 334 days (121~909 days). White-naped Cranes departed from roosting site to feeding site at every morning for foraging. If they were disturbed by some factors at feeding sites, they moved to mud flat in the Han river to forage and take a rest. Daily activity was consisted of six category; feeding, alert, locomotion, preening, comfort, social and other behaviors. Feeding was the highest portion among behaviors in the wintering area. Feeding, alert, locomotion and preening in daily activities significantly differed among feeding sites. We watched total 348 times of disturbances in the wintering sites. Artificial disturbances were vehicles, humans, bicycles and motorcycles. Natural disturbances were noises, animals and others. Disturbances in all wintering sites were highest in Yihwa-dong (134 times) and followed by Hongdopyong (109 times), Songpo-dong (64 times) and then Pyong-dong (44 times). And artificial disturbances (228 times) were more than natural disturbances (120 times). Especially, vehicle was one of the most checked factor in the wintering area.

• Journal of Oriental Neuropsychiatry
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• v.10 no.1
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• pp.39-51
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• 1999

The effects of Hyangbujapalmultang on the enhancement of learning and memory of AD model rats were studied with Morris water maze. Sample group was electrolytically lesioned on nucleus basalis of Meynert(nbM), and then daily treated with the medicine for two months. Control group with nbM lesion, and sham group with the sham operation were treated the vehicle for the same duration. The following results were observed. 1. As the learning trials of Morris water maze were proceeded, sham group showed the escape latency from $54.7{\pm}2.28$ seconds in 1st trial to $13.3{\pm}3.27$ seconds in 7th. The control group showed the escape latency from $58.0{\pm}1.78$ seconds in 1st trial to $51.3{\pm}3.52$ seconds in 7th. The sample group showed the escape latency from $57.0{\pm}2.21$ seconds in 1st trial to $28.4{\pm}4.82$ seconds in 7th. Therefore, these data shows that all three groups were improved in learning capacity as trials were proceeded, but the sample group showed more prominent improvement in learning compared with the control group(p<0.05). 2. In memory retention test of Morris water maze that counts the staying time in the target area during 30 seconds of freely swimming period, sham group stayed for $4.81{\pm}1.15$ seconds, the control group stayed for $1.27\pm}0.78$ seconds, and the sample group stayed for $4.17{\pm}1.47$ seconds. The analysis of the memory retention data shows that the sample group marked more improvement in memory retention compared with the control group, but could not obtained statistically significant result(p<0.05). With the experimental results above, Hyangbujapalmultang can be supposed to have the improving effects on the learning of AD model rats induced by electrolytic lesion of nbM.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.595-602
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• 2017

In Korea, much research and development have occurred to enhance the technological competitiveness of tuna purse seining fisheries. Due to these efforts, fishing efficiency has been improved with the development of radar, sonar and global positioning systems for fish detection and revisions to the hull forms of tuna purse seiners. However, for skiff boats, net boats and speed boats, which are auxiliary working boats mounted on tuna purse seiners, technology has lagged behind relative to the modernization of the main vessel. In this study, the hull of an existing propeller-based net boat with steel wire net to protect tuna was changed to the hull of a water jet propulsion vehicle to reduce resistance and improve maneuverability. As a result, a prototype of a water jet propulsion option was produced according to the aluminum structure strength standards specified by the Ministry of Oceans and Fisheries, and safety was confirmed by performing a drop test. Moreover, through a sea trial test, an existing net boat was shown to have a speed of 12.0knots and a towing force of 2,545 kgf at 2,500 RPM. The prototype had a speed of 26.7 knots and a towing force of 2,011 kgf at 3,200 RPM, which satisfied the towing capacity standards of auxiliary working boats mounted on tuna purse seiners.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.7.1-7.9
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• 2013

Objectives We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells. Methods To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with $PM_{10}$ and $PM_{2.5}$ inlets. Results The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to $3.2{\mu}m$. The mass concentrations of the metals in fine particles (0.1 to $1.8{\mu}m$) accounted for 45.6 to 80.4% of the mass concentrations of metals in $PM_{10}$. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the $PM_{10}$ mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells. Conclusions We found that exposure to $PM_{2.5}$ and $PM_{10}$ from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the $PM_{2.5}$ treatment were higher than those with $PM_{10}$. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1250-1260
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• 2014

In this paper, a novel resource scheduling, which is used for hub network based long distance airborne tactical communication, is proposed. Recently, some countries of the world has concentrated on developing data rate and networking performance of CDL, striving to keep pace with modern warfare, which is changed into NCW. And our government has also developed the next generation high capacity CDL. In hub network, a typical communication structure of CDL, hybrid FDMA/TDMA can be considered to exchange high rate data among multiple UAVs simultaneously, within limited bandwidth. However, due to different RTT and traffic size of UAV, idle time resource and unnecessary packet transmission delay can occur. And these losses can reduce entire efficiency of hub network in long distance communication. Therefore, in this paper, we propose RTT and data traffic size based UAV scheduling, which selects time/frequency resource of UAVs by using iterative sorting algorithm. The simulation results verified that the proposed scheme improves data rate and packet delay performance in low complexity.

• Journal of Korean Society of Transportation
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• v.10 no.1
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• pp.55-62
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• 1992

교통수요는 교통정책 및 교통시설 계획의 수립 및 평가에 중요한 영향을 미치게 되므로 교통수요의 예측은 교통연구에서 중요한 부문을 차지하고 있다. 도로밑에 설치된 전자차량감지기(Electronic Vehicle Detector)로부터 자동 수집된 링크 교통량 자료(Traffic Counts)를 주요 입력자료로 이용하여 계획지역의 기종점 통행표(Origin Destination Trip Matrix)를 작성할 수 있는 기법 들이 최근 수년동안 많이 발달하게 되었다. 이러한 새로운 기법들은 가구조사(Home Inteview), 노변면접조사(Road-Side Interview)등을 토하여 조사된 자료를 기초로하는 전통적은 4단계 교통수요추정방법(Conventional 4-Stage Estimation Method)-통행발생(Generation), 통행분포(Distribution), 수단선택(Modal Split), 교통배분(Assignment)-과 비교하여 첫째로 정확도가 높은 링크 교통량 자료를 별도의 조사를 거치지 않고서도 수집이 가능하기 때문에 조사비용이 거의 들지 않아도 되어 경제적이고, 둘째로 전통적인 수요예측방법들에서 요구되어지는 복잡한 모형수립 및 계수조정(Parameter Calibration)이 필요하지 않아 간편하고 셋째로 오래전에 작성된 기종점 통행표를 단순히 링크 교통량 자료만을 이용하여 쉽게 보완할 수 있어 지속적인 자료의 축적(Data Age-ing)이 가능하며 더 나아 가서 소위 연속적인 교통 계획 및 교통시설관리(Continuous Transport Planning and Management)를 가능케 하는 등의 여러 장점 때문에 많은 주목을 받아 오고 최근 몇 년이 꾸준히 실무에 유용하게 적용이 되고 있는 실정이다. 본 연구는 링크 교통량자료를 이용하여 기종점 통행표를 작성하기 위하여 개발된 기존의 여러 기법들 가운데 특히 용량제약조건(Capacity-Restrained Condition)하에서 기존의 방법들을 상호 검토한 후 Wardrop의 교통망 평형원칙(Wardrop's First Network Equilibrium Principle)을 만족하는 새로운 추정기법을 제의하고 이의 시험결과를 논의하는 것을 주요내용으로 한다. 링크 교통량 자료를 이용하여 기종점 통행표를 작성하는 기법들의 근본 목표는 조사된 링크 교통량(Ob-served Traffic Counts)에 가장 근접한 교통망 통행 배정 링크 교통량(Assigned Link Volumes)을 재현(Re-producing)할 수 있는 기종점 통행표들 중에서 최적의 기종점 통행표를 발견하는 것이다. 따라서 교통망에서 통행자의 여행 경로 배정을 가장 잘 반영할 수 있는 현실적인(Realistic) 교통망 통행 배정 모형(Net-work Traffic Assignment Model)의 선택은 중요한 요소가 되며 특히 교통망에 교통체증(Traffic Conges-tion)이 심할 경우 교통망 통행자 평형조건(Network Traffic Equilibrium Condition)을 고려하기 위한 특별한 처리가 요구되어진다. 본 연구는 Whllumsen(Hall, Van Vliet and Willumsen, 1980)에 의하여 개발된 ME2(Maximum Entropy Matrix Estimation)기법에서 반복식 추정방법(Sequential Estimation Method)을 사용할 경우 Wardrop의 평형조건을 만족하는 기종점 통행표를 구할 수 없다는 단점을 극복하기 위한 방안으로서 엔트로피 극대화문제와 교통망 평형 조건(Entropy Maximisation and Network Equilibrium Condition)의 두 문제를 동시에 해결할 수 있는 새로운 수식모형과 이를 풀기 위한 알고리즘(Simultaneous Solution Algorithm)을 제의하였다. 제의된 수식모형과 알고리즘을 예제 교통망(Example Network)을 이용한 시험하고 그 결과를 ME2 의 반복식 추정 방법으로부터 구한 기종점 통행표와 비교 검토하였다.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.37-44
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• 2015

Objectives : The present study was designed to evaluate the anti-inflammatory and anti-oxidative stress activities through regulation of Nrf2-mediated genes by Rhei rhizoma and Glycyrrhiza rhizoma combined extract (RGE) in reflux esophagitis.Methods : The antioxidant activity of RGE in vitro was measured in terms of radical scavenging capacity such as DPPH and ABTS. RGE was administered at 350 mg/kg body weight prior to induction of reflux esophagitis. Reflux esophagitis was induced that tied the pylorus and the transitional junction between the forestomach and the corpus in Sprague-Dawley rats.Results : RGE scavenged DPPH and ABTS effectively and IC₅₀of RGE each were 4.9 μg/ml and 45.6 μg/ml. Our results show that RGE administration markedly ameliorated mucosal damage upon histological evaluation. In serum and esophagus tissue, RGE significantly suppressed the oxidative stress biomarkers. Reflux esophagitis induced rats exhibited down-regulation of antioxidant-related proteins in the esophagus; however, the levels with treatment of RGE were significantly higher than those of vehicle reflux esophagitis rats. RGE treatment caused significant reductions in activation of NF-κB transcription factor. Thus, RGE significantly exhibited potent anti-inflammatory activities by suppressing the protein expression levels of pro-inflammatory proteins such as COX-2 and iNOS and inflammatory cytokines such as TNF-αin the esophagus tissue.Conclusions : Reflux esophagitis caused considerable levels of oxidative stress in the esophageal mucosa and the administration of RGE reduced the esophageal mucosa damage through the regulation of Nrf2 and NF-κB pathways. Our findings can considered as supplementary therapy in the prevention or treatment of reflux esophagitis.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.240-247
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• 2014

Acaiberry (Euterpe oleracea Mart.) is widely diffused in amazon and is known that has high antioxidant capacity and potential anti-inflammatory activities. The aim of this study was to evaluate analgesic effects of acaiberry in formalin-induced orofacial pain through p38 mitogen-activated protein kinases (p38 MAPK) and nicotinamide adenine dinucleotide phosphate 4 (NOX4) pathway. Rats were divided into 5 groups (n=6); formalin (5%, $50{\mu}L$), formalin after saline (vehicle) or acaiberry (16, 80, 160 mg/kg, intraperitoneally). The nociceptive response was investigated all of groups, p38 MAPK or NOX4 were analysed at dose of 80 mg/kg of acaiberry in rat's medulla oblongata and adrenal gland. Results indicated that acai berry produced analgesic effect in a dose-dependent manner and significantly reduced formalin-induced nociceptive response at 15~40 min. Acaiberry (80 mg/kg) decreased the increased p38 MAPK activation and NOX4 expression in medulla oblongata and adrenal gland. Based on these results, acaiberry is believed to be useful for modulation of orofacial pain and its treatments because of its anti-inflammatory and antioxidative effects.