• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.38-45
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• 2002

Hydrates are solid cryctallines resembling ice in appearance, which are consist of a gas molecule surrounded by a cage of water molecules. Because of containning a large amount of methane, hydrates have been considered as a future energy resource. However, the formation of hydrates in the oil and gas industries has been known as a serious problem for a long time. The formation of hydrate in pipeline is common in seasonally cold or sub-sea environments with low temperatures and high pressures. Especially, hydrate plug formation becomes a real menace to flow assurance in inadequately protected transmission lines. This study was carried out for the purpose of understanding mechanism of hydrate plugging and examining formation conditions of hydrate in high pressure gas pipeline. In this study, we measured hydrate equilibrium conditions under the various flowing conditions with the methane. The results were presented both the plugging tendency and the effect of flowing velocity.

• Korean Security Journal
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• no.29
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• pp.279-300
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• 2011

Countries recognize seriousness and concern about aviation terrorism, try to stamp out of it but aviation terrorism has been increasing in the world. Airport security is completely up to the result of security screening for passengers, check-in baggages and cargo at the check point. To complete effectively human and physical screening at the airport, it is essential to secure modernized screening equipment and specialized security screener, and airport security supervisor to supervising them. In this study, A survey conducted to find out the effect on screening equipment operating factors of airport security supervisor's individual attitude. The results of the study are as follow First, the duty view of airport security supervisor meaningfully affect expertise of screening equipment operating factors, satisfaction, reliability, and education and training, national point of view meaningfullly doesn't affect screening equipment operating factors. Second, the working condition effects on the education and training, if the working condition is getting better, intent to change occupation is getting lower. Third, duty stress meaningfully effects on the intent to change occupation, now airport security supervisor works in poor condition. Therefore, airport security supervisor needs to be prude of protecting the airport from the terrorism and various attacks and various kinds of aviation security regulations and procedures and comply with operating standards and keep the life of the country and its people, and needs to change awareness. And It is nessasary for government or airport authority or airline to prepare countermeasure for the improvement of their labor conditions.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.831-840
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• 2019

The X-ray detector by liquid crystal with front light was proposed and verified by a X-ray image. The proposed detector utilizes the visible light instead of the electric signal by transistor. Therefore, it shows low noise and can be fabricated at low cost. The liquid crystal detector uses the orientation change of the liquid crystal molecule by conductivity change of the photoconductive layer. We can get the X-ray image from the transmitted light through the liquid crystal. The X-ray dose was calibrated from the measured transmittance of the visible light after comparison to the reference transmittance curve of the liquid crystal. The amorphous Se was used for photo con ducting layer and parylene was used for the liquid crystal alignment instead of the conventional alignment layer which needs high-temperature process over 200℃. The proposed X-ray detector can decrease the X-ray dose by high sensitivity which was verified by simulation. After the fabrication of the X-ray detector, the X-ray image was obtained as a function of the bias voltage to the liquid crystal. 10 lines/mm resolution was obtained from the line pattern and we will apply it to the 17inch diagonal liquid crystal X-ray detector with 3π retardation.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.74-78
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• 2002

Purpose : Proper diagnosis of group A streptococcal pharyngitis that may cause chronic diseases in childhood is not easy because its signs and symptoms would be nonspecific. Because results of classical throat culture delays for one to two days, we'd like to determine whether early antibiotics would be introduced with according to the clinical score system. This study was undertaken to evaluate of clinical usefulness of scoring system based on the clinical and laboratory findings. Methods : From Jan. 1998 to Dec. 2000, 10 clinical items based on modified 9 items by Breese in 1977 were checked in patients with pharyngitis who visited on outpatients clinic of pediatrics, Kyunghee University Hospital. We compared the results of throat culture with the points of clinical score system. Results : Out of 45 cases, the positive culture for Group A Streptococcus was 20 and negative culture was 25. When we applied more than 30 points of score, which correspond to 70 percentile of study population, the sensitivity and specificity were 35.0% and 96.0%, respectively. Conclusion : Although sensitivity was relatively low this scoring system, but the high specificity may be useful diagnostic tool in the areas where the rate of isolation of Group A Streptococcus is low.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.104-108
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• 2016

The objective of this study was to determine how feeding forage and concentrate separately (SF) or as a total mixed ration (TMR) affects enteric methane production of cattle. Six Holstein steers ($203{\pm}22.5kg$) were used in a $2{\times}3$ changeover design experiment. Experimental diets (TMR and SF) consisted of compound feed, timothy hay and soybean curd residue in a ratio of 40:48:12, respectively, and diets were fed at 10% of metabolic body weight, on an as-fed basis. There were no differences in dry matter intake and enteric methane production (g/d) between SF and TMR but the methane conversion rate (methane energy/GE intake) of TMR was significantly higher (p=0.05) than that of SF. The mean methane emission factor (kg/head/year) and conversion rate of the two treatments were 21.4 and 0.05, respectively. There was a strong relationship between metabolic body weight and enteric methane production (p<0.001). At the present time, further studies may be necessary in order to establish the effects of TMR and SF on enteric methane production.

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1073-1074
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• 2003

본 연구는 고학력 중년 여성을 대상으로 취업 여부에 따른 영양섭취 상태의 차이를 분석하여 고학력 중년 여성의 영양 및 건강관리를 위한 대책 마련의 기초자료로 활용하고자 시행되었다. 연구 대상자의 선정은 유의추출 방법으로 전업 여성은 고학력자 비율이 높은 대전시의 일정 지역에 거주하는 기혼여성으로 하였고, 취업여성은 여러 직업의 특성으로 인한 교란(confounding)을 줄이기 위하여 고학력 여성의 비율이 높은 기혼의 교사로 한정하였다. 연령에 의한 교란을 방지하기 위하여 연령대별로 동일 비율로 무작위 추출하여 전업여성 250명, 취업여성 236명을 대상으로, 24시간 회상법을 이용하여 조사 전일 하루동안의 식이 섭취 내용을 개별 면담으로 조사하였다. 1일 영양소 섭취 조사 결과 취업여성은 전업여성에 비해 인, 비타민 B$_1$, B$_2$를, 전업여성은 취업여성에 비해 지방 및 동물성 지방, 나트륨, 비타민 C, 엽산을 많이 섭취하고 있었다. P/M/S비는 전업여성 1/1.19/1.05, 취업여성 l/l.05/0.87로 나타나 취업여성이 전업여성에 비해서, 그리고 한국인 영양권장량의 기준(1/1/1)에 비해서 포화지방의 비가 낮았다. 또한 지방 에너지 구성비도 전업여성(24.38%)이 취업여성(23.29%)에 비해 높았고, 총 열량에 대한 동물성 지방의 섭취비율이 전업여성 12.44%, 취업여성 11.46%으로 나타나 전업여성이 취업여성에 비해 동물성 지방, 포화지방비, 지방에너지 구성비가 모두 높았다. 영양권장량에 대한 영양소 섭취 백분율에서 전업여성과 취업여성 모두 칼슘과 아연을 권장량에 비해 낮게 섭취하고 있었고, 질적 영양지수(INQ)도 두 군 모두에서 칼슘이 가장 낮게 나타났다. 인의 영양밀도(Nutrient Density)가 취업주부에서 높았던 점 외에는 영양밀도와 영양소 적정섭취비(NAR) 모두에서 비타민 B$_1$, B$_2$가 전업여성에 비해 취업여성이, 비타민 C가 취업여성에 비해 전업여성이 더 높았다. 한편 두 군 모두 INQ가 가장 높은 영양소는 인이었고, INQ가 가장 낮은 영양소는 칼슘으로 나타났으며, INQ가 1 미만인 영양소는 칼슘과 함께 철분으로 나타났다. 이는 1998년도 국민건강영양조사 결과에서 45세 이상 여성의 경우 관절염, 요통.좌골통, 디스크 등 근골격계질환 유병률이 남자보다 3배정도 높게 나타난 결과에 비추어볼 때 이들 관련 영양소에 대한 섭취 방안 지도의 필요성을 제시하고 있다. 결론적으로 고학력 중년 여성중 전업여성에 대해서는 지방 특히 동물성 지방 식품 섭취에 대한 적절한 영양교육과 식사관리 지도가 요구된다 하겠다. 또한 고학력 중년 여성은 취업 여부에 관계없이 칼슘과 철분이 많이 함유된 식품으로 식사량을 증가시켜 주는 영양 지도 및 영양 보강 대책이 요구되며, 칼슘과 인의 적정섭취비가 되도록 인의 섭취를 낮추는 식생활 지도가 필요하다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.22-30
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• 2015

Recently ITS have been increasingly applied on the roads to resolve traffic problems. Especially, Variable Message Sign (VMS), which is the one of ITS for traffic management and traffic safety, can be used for providing information about road conditions, climate conditions. In this study, data acquisition and statistical analysis were conducted for estimating safety impacts of providing traffic information through VMS. As a result of analyzing traffic characteristics before and after providing traffic information through VMS, average travel speed was decreased and vehicles tended to drive on centerline of lanes in 1st and 2nd lane after providing traffic information through VMS. Also, in order to analyze safety impacts of provided VMS traffic information, traffic safety hazard zone was established in each lane and probability distributions of passing traffic on the study area was estimated through Anderson-Darling Test. As a result of this, safety impacts of VMS traffic information in 1st lane could, on average, increase in left and right side of the lane by 0.69% and 7.07%, respectively. In case of 2nd lane, safety impacts could, on average, increase in left and right side of the lane by 2.71% and 0.02%, respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.4
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• pp.12-19
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• 2014

A signal plan focused on vehicle traffic could easily overlook vulnerable priority signals, although the importance of vulnerable movements is increasingly recognized in recent years. Especially, the vulnerable are sometimes faced with dangerous situations when crossing roads with a signal plan based on design values of average, non-vulnerable persons. This study is focused on how to minimize the vehicle delay while simultaneously considering traffic flow and providing traffic safety by increasing road crossing time for pedestrians. For this purpose, a priority signal control strategy for the vulnerable, considering vehicle traffic flow, has been tested. Practical implication and a microscopic computer simulation has shown that the proposed method could provide a small decrease (about 6.2%) in pedestrian delay, a small increase (about 8.5~13.3%) in travel speed of passing traffic, and a considerable decrease (16.2~26.9%) in vehicle travel time. These findings suggest that the proposed signal control strategy could increase pedestrian safety and diminish delay of vehicle travel.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.815-820
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• 2008

Recently the frequency assignment and the technical specifications of UWB systems for communications are completed. Therefore many UWB systems have been developed. In our country $3.1{\sim}4.8GHz$ and $7.2{\sim}10.2GHz$ are assigned for UWB systems for communications. When we consider RF technologies and the easy implementation of UWB systems, UWB systems used in the low band are more developed than high band systems. In this paper we design and implement a BPF for low band UWB systems by means of considering the easy implementation of UWB systems. The designed and implemented BPFs are low band filter and low band channel filters. The measured results of the low band filter show that the filter has 21.85dB and 17.91dB attenuation at 3.1GHz and 4.8GHz, 1.53GHz of -10dB bandwidth and 2dB of insertion loss. Low band can be divided into 3 channels with 500MHz of the channel bandwidth. The channel filter for channel number 1 has the characteristics of 24.85dB attenuation at 3.1GHz, 0.61GHz of -10dB bandwidth and 1.87dB of insertion loss. The filter for channel 3 in low band has 19.2dB of attenuation at 4.8GHz, 0.49GHz of -10dB bandwidth and 2.49dB of insertion loss.

• Journal of Korea Port Economic Association
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• v.25 no.2
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• pp.129-148
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• 2009

In 2006, the share of fisheries distribution in Busan amounted to 1.9 million ton, which was 41 percent of the whole country. In details, coastal fishery 334 thousand ton(14% of the whole country), deep sea fishery 452 thousand ton(82%), import fishery 964 thousand ton(70%), export fishery 157 thousand ton(43%) were distributed in Busan region, respectively. Recently, the share of fisheries sale through e-commerce is increasing owing to the growth of IT and competitive price of its products. and the sale share of large discount store is also on the 10% more increase owing to the effectiveness of distribution structure. Hereafter these structure changes of fisheries distribution in Busan will be more intensified. Therefore, after reflecting the change in distribution policy of Busan Fisheries, the directions of distribution policy should be established, as follows. Distribution policy to prepare for increasing of sales ratio in large discount store