• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.4
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• pp.358-371
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• 2014

For the systematic scientific management in Cheonsu Bay of Korea, this study was conducedt to survey the particle composition, organic matter(I.L.) and heavy metals in farming and non-farming areas. The sediment of study area showed feature mixed property by sand, silt and clay. The farming area showed superior by fine-grained sediment, non-farming area showed superior by coarse-grained sediment. The organic pollution of farming area were appeared to be heavily polluted more than non-farming area. The concentration of total nitorgen in sediment was higher farming area than non-farming area. Also, in the case of heavy metals pollution in sediments, farming area was higher than non-farming area. The correlation analysis among to heavy metals, organic matter and particle size was found to have a good interrelationship. For evaluation of heavy metals pollution of sediments, three criteria are applied, Enrichment Factor(EF), Geoaccumulation index(Igeo) and NOAA criteria for sediment. In the case of EF, Heavy metals pollution was appeared to artificial effect all heavy metals if except Cu. In the case of Geoaccumulation index, Cu, Al, Pb was shown zero grade, that is non polluted group, and Cd, Hg, Cr was shown to 0~1 grade, that is mid polluted group, As was shown to 2 grade, that is moderately polluted group. In the case of NOAA, pollution levels of heavy metals except Cd belonged to a group of ERL(Effect range low)~ERM(Effect range median).

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.508-508
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• 1998

위험물 차량사고는 일반차량의 교통사고시 발생하는 인명피해, 재산피해, 교통지체 외에 부가적으로 환경적 영향에 의한 엄청난 인명 및 재산손실을 유발시킬 수 있다. 따라서 이러한 위험물차량사고를 예방하고 피해를 최소로 줄이기 위해서는 위험물수송경로의 신중하고 체계적인 결정이 필수적이라 할 수 있다. 외국의 경우, 위험물의 방출이 미치는 환경적 영향에 대한 인식이 확대되면서 위험물 수송시 응급처리에 관한 연구, 위험물 수송에 따른 위험도 평가에 관한 연구, 위험물 수송시 고려해야할 여러 조건에 관한 연구, 위험물 수송경로 설정에 관한 연구 등이 진행되고 있다. 반면에 우리 나라는 위험물차량관리와 사고처리에 대해 실시간적인 관리를 목표로 하는 국가차원의 계획을 수립하고는 있지만, 현재 이와 관련된 연구는 거의 없는 실정이다. 앞으로 산업발달에 따른 위험물수송량의 증가와 환경의식의 변화에 따라 위험물수송 및 사고처리 등에 관한 연구가 필요할 것이다. 따라서, 본 연구는 위험물차량의 운송경로를 결정할 때 고려해야 할 여러 가지의 기준 및 목표에 따라 위험물수송경로를 설정하는 모형을 제시함으로써 위험물수송에 수반되는 위험을 최소화하면서 위험물차량의 통행시간, 거리, 비용 등을 최적화하여 위험물수송의 안전 및 운영효율성을 향상시키고자 한다. 먼저, 위험물 수송경로의 기준지표로 사용될 위험도를 산정하기 위해 링크 주변노출인구, 밀도 등을 변수로 하는 모형식을 제안하고, 두 번째로 산정된 위험도를 기반으로 최적경로를 결정하는 알고리즘을 제안하였다. 마지막으로 가상 네트웍에 본 연구에서 제안된 모형을 적용하고 현재 일반적으로 사용되는 최단경로와 비교·분석하였다.것은 운송거리와 운송비용이 각각 주요한 변수라는 것이다. 모형의 타당성을 검증하기 위해서는 logilikelihood 값을 구하여 $\rho$^2분석을 시행하였다. 여기서는 각 품목별로 $\rho$^2값이 약 0.15~0.3의 비교적 높은 수치를 보여주고 있으므로 모형의 설명력이 어느 정도 있다는 것이 아울러 증명이 되었다. 상관관계에 대한 분석에서는 영업용 차량간의 상관관계가 높게 나타났으며, 이는 곧 영업용 화물차량을 적재중량별로 구분하는 것이 별 의미가 없음을 의미한다. 다시 말하면 자가용 차량을 보유하고 있지 않은 회사는 다른 운송전문업체에 화물운송을 의뢰하게 되므로 출하중량에 따라 화물차량을 구분하는 것에 대해서 그다지 큰 고려를 하지 않는 것으로 해석할 수가 있다.적합함을 재확인함. 6. 혼잡초기를 제외한 혼잡기간 중 대기행렬길이는 밀도데이터 없이도 혼잡 상류부의 도착교통량과 병목지점 본선통과교통량만을 이용하여 추정이 가능함. 7. 이상에 연구한 결과를 토대로, 고속도로 대기행렬길이를 산정할 수 있는 기초적인 도형을 제시함.벌레를 대상으로 처리한 Phenthoate EC가 96.38%의 방제가로 약효가 가장 우수하였고 3월중순 및 4월중순 월동후 암컷을 대상으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.761-778
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• 2017

The need of the underground space for the infrastructures in urban area is increasing, and especially the demand for shallow tunnels increased drastically. It is very important that the shallow tunnel in the urban area should fulfill not only its own safety conditions but also the safety condition for the adjacent structures and the surrounding sub-structure. Most of the studies on the behavior of shallow tunnels concentrated only on their behaviors due to the local deformation of the tunnel, such as tunnel crown or tunnel sidewall. However, few studies have been performed for the behavior of the shallow tunnel due to the deformation of the entire tunnel. Therefore, in this study the behavior of the surrounding ground and the stability caused by deformation of the whole tunnel were studied. For that purpose, model tests were performed for the various ground surface slopes and the cover depth of the tunnel. The model tunnel (width 300 mm, height 200 mm) could be simulationally deformed in the vertical and horizontal direction. The model ground was built by using carbon rods of three types (4 mm, 6 mm, 8 mm), in various surface slopes and cover depth of the tunnel. The subsidence of ground surface, the load on the tunnel crown and the sidewall, and the transferred load near tunnel were measured. As results, the ground surface subsided above the tunnel, and its amount decreased as the distance from the tunnel increased. The influence of a tunnel ceased in a certain distance from the tunnel. At the inclined ground surface, the wider subsidence has been occurred. The loads on the crown and the sidewall were clearly visible, but there was no effect of the surface slope at a certain depth. The load transfer on the adjacent ground was larger when the cover depth (on the horizontal surface) was lager. The higher the level (on the inclined surface), the wider and smaller it appeared. On the shallow tunnel under inclined surface, the transfer of the ambient load on the tunnel sidewall (low side) was clearly visible.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.4
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• pp.299-304
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• 2007

There are to be some cracks on the material degradation part or the stress concentration parts of the main members, which carry on over-loads, of structures. Because these cracks can be used to evaluate the structural health status, it is important to monitor the crack growth for maintaining the structural safety. In this study, the fiber Bragg grating sensor with a drop ball was developed as a sensor for crack growth detection of an existing crack. The crack growth detection sensor was constructed with three parts: a probe part, a wavelength controling light source and receiver part, and an impact part. The probe part was just formed with a fiber Bragg grating optical fiber The wavelength controling light source part was composed of a current supplying circuit, a DFB laser diode, and a TEC controling circuit for wavelength control. Also, the impact part was just implemented by dropping a steel ball. The performance of this sensor was confirmed by the experiments of the crack detection with an aluminum plate having one existing crack. According to these experiments, the difference of the sensor signal outputs was correlated with the crack length. So, it was confirmed that this sensor could be applied to monitor the crack growth.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.74-88
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• 2020

A Cooperative Intelligent Transportation System (CITS) provides useful information on upcoming hazards in order to prevent vehicle collisions. In addition, the availability of individual vehicle travel information obtained from the CITS infrastructure allows us to identify the level of road safety in real time and based on analysis of the indicators representing the crash potential. This study proposes a methodology to derive road safety content, and presents evaluation results for its applicability in practice, based on simulation experiments. Both jerk and Stopping Distance Index (SDI) were adopted as safety indicators and were further applied to derive road section safety information. Microscopic simulation results with VISSIM show that 5% and 20% samples of jerk and SDI are sufficient to represent road safety characteristics for all vehicles. It is expected that the outcome of this study will be fundamental to developing a novel and valuable system to monitor the level of road safety in real time.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.234-242
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• 2017

This study was conducted to provide basic data of Cirsium setidens Nakai in different harvest time that will be applied for development of functional foods and ingredients. We investigated pectiolinarin and pectolinarigenin content, total flavonoids content and antioxidant effects (DPPH radical scavenging activity and ORAC assay) of C. setidens Nakai. Our results showed that the pectolinarin and total flavonoids contents of C. setidens Nakai in harvesting time ranged from $43.13{\pm}0.22$ to $95.65{\pm}0.34mg/g$ and from $32.81{\pm}1.68$ to $40.43{\pm}0.35mg$ rutin equivalent (RE)/g, respectively. The DPPH radical scavenging activity of C. setidens Nakai did not show differences in harvesting time. The oxygen radical absorbance capacity (ORAC) value was highest in August (2016) extracts ($827.72{\mu}mole\;TE/g$). In addition, C. setidens Nakai exthanolic extract in harvesting time did not show any cytotoxicity up to $200{\mu}g/mL$. During adipocyte differentiation, C. setidens Nakai extract in harvesting time significantly inhibited lipid accumulation and ROS production, compared with the controls. These results suggest that C. setidens Nakai extract could be considered as a non-toxic natural resources of functional food ingredients and natural antioxidants.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.483-490
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• 2002

The aim of this study was to determine if a low-molecular weight casein hydrolysate has an anti- hypertensive effect in spontaneously hypertensive rats (SHR). Prior to the in vivo experiment, the casein hydrolysate was confirmed to be resistant to gastrointestinal digestion by confirming the retention of its potency as an inhibitor of angiotensin I-concerting enzyme after incubation with pepsin, trypsin, or chymotrypsin. The in vivo anti-hypertensive effect of the hydrolysate was determined by the tail cuff method. Following an oral administration of the hydrolysate solution, the systolic blood pressure (SBP) decreased by 12.9% (－28.9mmHg; P<0.05) at 3 h after the administration at a dose of 500mg/kg body weight. When the hydrolysate was administered as an emulsion with 30% egg yolk, its anti-hypertensive effect was even more greater at the same dose(－30.8mmHg or －15.9%; P<0.01). In a 50-day long-term trial where the casein hydrolysate was administered once a day, the SBP-lowering effect of the hydrolysate was apparent (P<0.05) from day 35 through the end. Moreover, organ weights and plasma glutamate oxaloacetate transaminase and glutamate pyruvate transaminase activities of the administered SHR were not significantly different from those of controls at the end of the long-term trial.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.133-142
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• 2010

This study was performed to investigate awareness of hand washing, hand washing behavior, and the levels of indicator microorganisms on hands of food handlers who work in the food court and cafeteria of a university campus. The three methods used were questionnaire survey by interview, direct observation in restrooms, and microbiological examination according to the Food Code of Korea. A positive attitude toward hand washing compliance was reported by the responded food handlers; however, improper hand washing and poor hand hygiene of the food handlers were recognized by the unnoticed direct observation. Significant differences were found between the questionnaire survey and the direct observation (p < 0.05) in hand washing compliance after using the toilet, duration of hand washing, use of hand washing agent, washing different parts of the hands, hand-drying method, temperature of water, and method of turning off the water. Samples taken from their hands before work showed higher level of standard plate count, total and fecal coliforms, and Escherichia coli than those taken after washing with water. After washing hands with antiseptic liquid soap, the bacterial populations including Staphylococcus aureus on hands were dramatically reduced. This study indicates that there is a remarkable difference between the food handlers' awareness of hand washing and their hand washing behavior. Poor hand washing compliance and hand hygiene were indicated by the positive results of total and fecal coliforms, E. coli, and S. aureus on hands of some food handlers. The findings of this study suggest that the hand hygiene of the food handlers need to be improved. More training/education on hand washing and hand hygiene of the food handlers should be necessary.

• Journal of Korean Society of Disaster and Security
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• v.14 no.1
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• pp.61-72
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• 2021

There is an increasing need for water supply plan using sustainable groundwater to resolve water shortage problem caused by drought due to climate change and artificial aquifer recharge has recently emerged as an alternative. This study deals with recharge potential assessment for artificial recharge system and quantitative assessment for securing stable water and efficient agricultural water supply adapt to drought finding optimal operating condition by numerical modeling to reflect recharge scenarios considering climate condition, target water intake, injection rate, and injection duration. In order to assess recharge potential of injection well, numerical simulation was performed to predict groundwater level changes in injection and observation well respect to injection scenarios (Case 1~4) for a given total injection rate (10,000 m³). The results indicate that groundwater levels for each case are maintained for 25~42 days and optimal injection rate is 50 m³/day for Case 3 resulted in groundwater level rise less than 1 m below surface. The results also show that influential area of groundwater level rise due to injection was estimated at 113.5 m and groundwater storage and elapsed time were respectively increased by 6 times and 4 times after installation of low permeable barrier. The proposed assessment method can be contributed to sustainable agricultural water supply and stable water security for drought adaptation.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.107-113
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• 2011

Plantago asiatica L. (PA), which is widely distributed in Korea, Japan and China, has traditionally been used as a popular folk medicine for the treatment of liver diseases. A variety of activities of PA was reported, that is hepatoprotective, anti-inflammatory, anti-glycation and anti-oxidant effect. Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent and has been reported to induce renal proximal tubular necrosis. In the present study, pre-treatment with PA extract (PAE) in Wistar rat followed by Fe-NTA i.p. treatment (13.5 mg Fe/kg body weight) was performed to detect the renal protective effect of PAE. Only Fe-NTA treated group showed increases in the level of serum blood urea nitrogen (BUN) and serum creatinine (Cr), and renal tissue malondialdehyde (MDA), product of lipid peroxidation. Moreover, the level of biomarkers indicate the antioxidants status, reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GR) were decreased. However, PAE pre-treated group showed decreases in the levels of serum BUN, serum Cr and renal tissue MDA in concentration dependent manner and increases in the level of GSH, GST and GR. These results are significantly different (p < 0.05) to the other groups. Our data suggest that PAE may be used as an chemopreventive material against Fe-NTA-mediated renal oxidative stress.