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A Study on the Deterioration Process of 22kV Power Cables in Operation (운전 중인 상태에 있는 22kV 전송선로 케이블의 열화 과정해석에 대한 연구)

  • Lee, Kwan-Woo;Um, Kee-Hong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.3
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    • pp.127-133
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    • 2013
  • As an essential part of current industrial society, electric power energy is contantaly increasing in pace with the development of science and technology. In order to meet the demand of electric power, power facilities which take care of the higher voltage and bigger capacity is required. To produce and supply electric power on a sound basis the electric facilities should operate with reliability. To prevent disasters in advance, the high quality facilities should be manufactured, and a constant management should be done. When the power facilities cause accidents, the result is huge national deficits. Since the power facilities play a pivotal role in the key industry of national infrastructures of they should operate for a long time in maintaining a stable state, and the accidents can be prevented in advance. The lifetime of a power cable is considered to be 30 years at the time of manufacture, but in real fields, accidents of cable occur 8-12 years from the start of operation, resulting in a heavy loss of properties. In this paper, we will show that we have found out the cause and process of the deterioration of 22kV cable systems in operation. The result is that the process of deterioration does not follow the Weibull distribution only ; but rather, after the heat deterioration the Weibull distributed deterioration comes, then the cable is destroyed due to the partial discharge resulting from the Weibull distributed deterioration.

Importance and Influence in Factors of Selecting Dental Clinics in Some Regions (일부지역의 치과병·의원 선택요인의 중요도와 영향)

  • Chun, Ae-Jong;Lee, Ka-Yean
    • Journal of dental hygiene science
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    • v.10 no.1
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    • pp.45-54
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    • 2010
  • The purpose of this study was to offer the importance on factors of selecting dental institution according to general characteristics targeting general dental patients, and the information of having important influence upon choosing dental clinic and dental hospital. The survey was carried out from August 2009 to September. As a result of analyzing SAS(ver 9.1), the following conclusions were obtained. In the importance on factors of selecting dental institution according to general characteristics, it was thought to be important in convenience of movement or mobility such as distance, transportation, and parking convenience according to age level. According to final academic background, the importance in a factor of rumor in dental clinic was high(p < 0.05). According to job, the significant difference was shown in rumor of dentistry and parking convenience(p < 0.05). According to income, the factor in the appearance of training a medical specialist was indicated to be statistically higher in the group with over 5 million won than the group with under 2 million won(p < 0.05). Given seeing the distribution of opinion about dental hospitals (comparison with dental clinics), the excellence in the medical staff's ability was indicated to be the highest in all of the factor of influencing the use satisfaction(${\beta}=0.18$), the factor of influencing the recommendation level(${\beta}=0.21$), and the factor of influencing the re-use intention(OR=2.09).

Spatial Variability of in situ and GOCI and MODIS Chlorophyll and CDOM in Summer at the East Sea (여름철 동해의 현장측정치와 GOCI와 MODIS 위성 자료로 측정한 엽록소와 유색용존유기물의 공간 변동성)

  • Park, Mi-Ok;Shin, Woo-Chul;Son, Young-Baek;Noh, Tae-Geun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.4
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    • pp.327-338
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    • 2015
  • Because of impact on the underwater light field, CDOM can influence the accuracy of global satellite-based measurement of ocean chlorophyll and primary productivity. So we investigated the distribution and seasonal variation of CDOM in the East Sea during summer 2009 and 2011. Among them we report two distinctively different summer cases between 2009 and 2011 year, in which showed the different main sources for CDOM. Regulating factors and sources of CDOM in the East Sea were examined. Comparison between in situ and satellite derived Chl a and CDOM were made to find an influence of CDOM on measurement of satellite derived Chl a. Similar pattern and matching of MODIS Chl a with in situ Chl a 2009 was comparable, but significant discrepancy between MODIS Chl a and in situ Chl a was found, when CDOM was high in summer of 2011. GOCI data showed better matching with in situ data for both Chl a and CDOM, compared to MODIS data in summer of 2011. The presence of high CDOM at the surface layer supplied by vertical mixing seems to affect on the overestimation of Chl a by satellite data.

The Implementation of Real-time Performance Monitor for Multi-thread Application (멀티스레드 어플리케이션을 위한 실시간 성능모니터의 구현)

  • Kim, Jin-Hyuk;Shin, Kwang-Sik;Yoon, Wan-Oh;Lee, Chang-Ho;Choi, Sang-Bang
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.3
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    • pp.82-90
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    • 2011
  • Multi-core system is becoming more general with development of microprocessors. Due to this change in performance improvement paradigm, switching conventional single thread applications with multi thread applications. Performance monitoring tools are used to optimize application performance because of complexity in development of multi thread applications. Conventional performance monitoring tools are focused on performance itself rather than user friendliness or real-time support. Real-time performance monitor identify the problem while multi-threaded applications should be performed as well as check real-time operating status of the application. So it can be used as an effective tool compared to non-real-time performance monitor that only with simple performance indicators to find the cause of the problem. In this paper, we propose RMPM(Real-time Multi-core Performance Monitor) which is real-time performance monitoring tool for multi-core system. Observation period is optimized by comparing relation between overhead due to performance evaluation period and accuracy. Our performance monitor shows not only amount of CPU usage of whole system, memory usage, network usage but also aspect of overhead distribution per thread of an application.

A Categorization Method based on RCBAC for Enhanced Contents and Social Networking Service for User (사용자를 위한 향상된 콘텐츠 및 소셜 네트워킹 서비스 제공을 위한 RCBAC 기반 분류 방법)

  • Cho, Eun-Ae;Moon, Chang-Joo;Park, Dae-Ha
    • Journal of Digital Contents Society
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    • v.13 no.1
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    • pp.101-110
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    • 2012
  • Recently, social network sites are very popular with the enhancement of mobile device function and distribution. This gives rise to the registrations of the people on the social network sites and the usage of services on the social sites is also getting active. However, social network sites' venders do not provide services enough compared to the demand of users' to share contents from diverse roots by users effectively. In addition, the personal information can be revealed improperly in processes sharing policies and it is obvious that it raises a privacy invasion problem when users access the contents created from diverse devices according to the relationship by policies. However, the existing methods for the integration management of social network are weak to solve this problem. Thus, we propose a model to preserve user privacy, categorize contents efficiently, and give the access control permissions at the same time. In this paper, we encrypt policies and the trusted third party classifies the encrypted policies when the social network sites share the generated contents by users. In addition, the proposed model uses the RCBAC model to manage the contents generated by various devices and measures the similarity between relationships after encrypting when the user policies are shared. So, this paper can contribute to preserve user policies and contents from malicious attackers.

A Study on BMI Regarding Life Style Related with Health of Middle School Students (중학생들의 건강 관련 생활습관에 따른 BMI 연구)

  • Lee, Chang-Hee;Ha, Hun-Yong;Kim, Hee-Taek;Kim, Nam-Song
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.25 no.1
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    • pp.84-103
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    • 2012
  • Objectives : The middle school students'life style were studied with focus on Body Mass Index(BMI). Information was collected during 1st June 2009 to 10th July from 397 students(both male and female) by the subjective survey centered on personal characteristic, understanding about health in general, everyday activities, eating habits, preference in food, understanding about diet and obesity, and thoughts about fitness and diet. Methods : Students were selected from six classes by convenience sampling, then the final analysis was performed on 397 self-administered questionnaires, excepting 5 questionnaires, which have insincere answers. The data collection was carried out by SPSS(V.14.0 English Version), and the data was verified by $x^2$-test, ANOVA, multiple regression analysis. Results and Conclusion : The survey subjects were in the following distribution of body weights - underweight: 63.6%, normal weight: 29.5% and 6.9% were overweight. There was significantly different between BMI and mothers' occupation and satisfaction with school life(p<0.05). As for the analysis(multiple regression analysis) on understanding about health, the factors that affect BMI are self recognition of figure and efforts to reduce weight. In terms of efforts for one's own health, 78.2% of under weight and 82.3% of normal weight were taking active initiatives. But 85.2% of the overweight students were not giving any efforts. As for the free time activities, more than half answered, 'playing with computers'(48.4 - 66.7%, 1.57 hours on average). As for TV, on average, 2.03 hours were spent in overall. And it turned out that the overweight students spent more time watching TV by 46.49 minutes(0.77 hours) on average(p<0.05). 7.4 hours was the average sleeping time. As for the eating habit,'quantity of meal, snack, meal between meals, fat reduction, and supplementary food'were shown to be related to the BMI(p<0.05). The instant food, meat and sweet food were shown to be also related to the BMI. In terms of knowledge about overweight and diet, only 8 students(2% of the total) answered all 10 questions correct. On average, 7-8 questions were correctly answered(53.9 %). When the scores were analyzed against the BMI by classifying the scores to high, middle and low categories, it showed a relationship by different weight group(p<0.02), and the overweight students had higher score by 0.82 compared to the underweight students. When thoughts and attitude on fitness and diet were analyzed in relationship to the BMI, the result was only - "I try to eat fruits more often"(fruits)(p<0.00).

Real-time Monitoring of Environmental Properties at Seaweed Farm and a Simple Model for CO2 Budget (해조양식장 수질환경 모니터링을 통한 이산화탄소 단순 수지모델)

  • Shim, Jeong Hee;Kang, Dong-Jin;Han, In Sung;Kwon, Jung No;Lee, Yong-Hwa
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.4
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    • pp.243-251
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    • 2012
  • Real-time monitoring for environmental factors(temperature, salinity, chlorophyll, etc.) and carbonate components( pH and $fCO_2$) was conducted during 5-6th of July, 2012 at a seaweeds farm in Gijang, Busan. Surface temperature and salinity were ranged from $12.5{\sim}17.6^{\circ}C$ and 33.7~34.0, respectively, with highly daily and inter-daily variations due to tide, light frequency(day and night) and currents. Surface $fCO_2$ and pH showed a range of $381{\sim}402{\mu}atm$ and 8.03~8.15, and chlorophyll-a concentration in surface seawater ranged 0.8~5.8 ${\mu}g\;L^{-1}$. Environmental and carbonate factors showed the highest/lowest values around 5 pm of 5th July when the lowest tidal height and strongest thermocline in the water column, suggesting that biological production resulted in decrease of $CO_2$ and increase of pH in the seaweed farm. Processes affecting the surface $fCO_2$ distribution were evaluated using a simple budget model. In day time, biological productions by phytoplankton and macro algae are the main factors for $CO_2$ drawdown and counteracted the amount of $CO_2$ increase by temperature and air-sea exchange. The model values were a little higher than observed values in night time due to the over-estimation of physical mixing. The model suggested that algal production accounted about 14-40% of total $CO_2$ variation in seaweed farm.

In-Vivo Heat Transfer Measurement using Proton Resonance Frequency Method of Magnetic Resonance Imaging (자기 공명영상 시스템의 수소원자 공명 주파수법을 이용한 생체 내 열 전달 관찰)

  • 조지연;조종운;이현용;신운재;은충기;문치웅
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.3
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    • pp.172-180
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    • 2003
  • The purpose of this study is to observe the heat transfer process in in-vivo human muscle based on Proton Resonance Frequency(PRF) method in Magnetic Resonance Imaging(MRI). MRI was obtained to measure the temperature variation according to the heat transfer in phantom and in-vivo human calf muscle. A phantom(2% agarose gel) was used in this experiment. MR temperature measurement was compared with the direct temperature measurement using a T-type thermocouple. After heating agarose gel to more than 5$0^{\circ}C$ in boiling hot water, raw data were acquired every 3 minutes during one hour cooling period for a phantom case. For human study heat was forced to deliver into volunteer's calf muscle using hot pack. Reference data were once acquired before a hot pack emits heat and raw data were acquired every 2 minutes during 30minutes. Acquired raw data were reconstructed to phase-difference images with reference image to observe the temperature change. Phase-difference of the phantom was linearly proportional to the temperature change in the range of 34.2$^{\circ}C$ and 50.2$^{\circ}C$. Temperature resolution was 0.0457 radian /$^{\circ}C$(0.0038 ppm/$^{\circ}C$) in phantom case. In vivo-case, mean phase-difference in near region from the hot pack is smaller than that in far region. Different temperature distribution was observed in proportion to a distance from heat source.

Characteristics of Water Temperature and Salinity in the Bottol Bada, Yeosu during Summer in 2010 (2010년 하계 보돌바다의 수온과 염분 특성)

  • Cho, Eun-Seob
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.4
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    • pp.301-306
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    • 2011
  • This study was determined to analysis the characteristics of water mass in the Bottol Bada, Yeosu in August, 2010 based on the data from the distribution of water temperature and salinity. Sampling was carried out a total of three times (i.e. July 29, August 13, and August 30, 2010) and performed at three stations. Observation was done during the period of time 10:00-15:00, indicating the decreasing tidal height and turn of tide. In July 29, thermocline was found at 4 m in St. 1, but the stratification did not observe in August 13 and August 30. The remarkable water temperature between surface and bottom was found in St. 2 and St. 3, whereas St. 1 did not find. A particular finding during this study showed a cold water mass at bottom layer from St. 2 and St. 3, which was first occurred in July 29 and persisted in August 30 without any of destruction. Water temperature had a remarkable fluctuation between surface and bottom, whereas salinity had a unique in St. 1. St. 2 and St. 3 showed the increasing salinity according to water depth in August 13 and August 30. Transparency had considerable fluctuations in St. 1 and St. 3 depending to sampling date, but St. 2 did not fluctuate. Consequently, the Bottol Bada had a significantly different water mass between inner and outer waters. Furthermore, strong irradiance and weak wind play an important role in developing the stratification between surface and bottom, in particular the introduction of offshore waters contribute to highly developing the stratification in the Bottol Bada during the period of August in 2010.

Molecular Cloning, Tissue Distribution and Segmental Ontogenetic Regulation of b0,+ Amino Acid Transporter in Lantang Pigs

  • Zhi, Ai-Min;Feng, Ding-Yuan;Zhou, Xiang-Yan;Zou, Shi-Geng;Huang, Zhi-Yi;Zuo, Jian-Jun;Ye, Hui;Zhang, Chang-Ming;Dong, Ze-Min;Liu, Zhun
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.8
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    • pp.1134-1142
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    • 2008
  • Cationic amino acid transporter $b^{0,+}AT$ (HGMW-approved gene symbol SLC7A9, solute carrier family 7, member 9) plays a crucial role in amino acid nutrition. In the present study, we describe the cloning and sequencing of porcine $b^{0,+}AT$. Based on the sequence of porcine $b^{0,+}AT$ deposited in the NCBI (National Center for Biotechnological Information), we identified a putative porcine homologue. Using rapid amplification of cDNA ends (RACE), the full-length cDNA encoding porcine $b^{0,+}AT$ was isolated. The porcine $b^{0,+}AT$ cDNA was 1,680 bp long, encoding a 487 amino acid trans-membrane protein. The predicted amino acid sequence was found to have 88.9% and 87.1% identity with human and mouse $b^{0,+}AT$, respectively. Real-time RT-PCR indicated porcine $b^{0,+}AT$ transcripts expressed in heart, kidney, muscle and small intestine. The small intestine had the highest $b^{0,+}AT$ mRNA abundance while the muscle had the lowest (p<0.05). Along the longitudinal axis, the ileum had the highest $b^{0,+}AT$ mRNA abundance while the colon had the lowest (p<0.05). The $b^{0,+}AT$ mRNA level was highest on day 7 and 90 in the duodenum (p<0.05). It increased from day 1 to day 26 in the jejunum (p>0.05) and had the highest abundance on day 60 (p<0.05). There was, however, no difference between day 1, 7, 26, 30, 90 and 150 (p>0.05). The strongest $b^{0,+}AT$ expression appeared on day 7 in the ileum before weaning, and then decreased till day 30 but rose gradually again from day 60 to 150 (p<0.05).