• Title/Summary/Keyword: 정지운(鄭之雲)

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Preliminary Estimation of Activation Products Inventory in Reactor Components for Kori unit 1 decommissioning (고리1호기 해체시의 원자로 구조물에서의 방사회 생성물 재고량 예비평가)

  • Lee, Kyung-Jin;Kim, Hak-Soo;Sin, Sang-Woon;Song, Myung-Jae;Lee, Youn-Keun
    • Journal of Radiation Protection and Research
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    • v.28 no.2
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    • pp.109-116
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    • 2003
  • Based on the necessity to evaluate the activation products inventory during decommissioning lot domestic nuclear power plants, a preliminary estimation of the activation products inventory for Kori unit 1, which is getting close to the end of lifetime, was carried out with ANISN and ORIGEN2 code. In order to calculate neutron nux using ANISN code, the reactor was divided into 9 zones from core to bioshield concrete for radial direction. Also :he cross-section of main nuclides were calibrated with neutron flux in the reactor pressure vessel(RPV) region. The results showed that 95 % of tile total radioactivity in RPV from reactor shutdown to 10 years came from the nuclides of $^{55}Fe,\;^{59}Ni,\;^{63}Ni\;and\;^{60}Co$. And the total radioactivity with cooling of more than 50 years after decommissioning was no more than 0.2 % of at the time of shutdown. Considering the weight of RPV is 210 tons, the total radioactivity of RPV reached to $5.25{\times}10^{6}GBq$ at shutdown time. As compared with the total radioactivity of bioshield concrete at reactor shutdown time, the radioactivity after tooling more than 10 years was below 1 %.

A Study on the Safety Code Development of Gas Engine Micro Combined Heat and Power System (소형 가스엔진 열병합 발전시스템 안전기준 개발)

  • Kwon, Jun-Yeop;Kim, Min-Woo;Lee, Jung-Woon
    • Journal of the Korean Institute of Gas
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    • v.25 no.4
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    • pp.27-35
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    • 2021
  • Recently, as a solution to the sharp drop in "power reserve ratio", it is being converted to a microgrid that enables bi-directional transmission and distribution. A microgrid is composed of a small-scale distributed power supply and a load. As a representative technology of distributed power generation, there is a Micro Combined Heat and Power system applied to homes and buildings. In this study, a safety standard was developed by dividing the power generation system, cooling system, lubrication system, and exhaust system to derive safety standards for a small gas engine power generation system with a gas consumption less than 232.6kW (200,000 kcal/h). In the case of the power generation system, a filter was installed and the system was stopped by detecting gas leakage and abnormalities in engine speed or output and the cooling system is stipulated to stop the system in case of insufficient cooling water or overheating. The lubrication system monitors the pressure and temperature of the lubricating oil and stops the system when an abnormality occurs, and the exhaust gas emission concentration regulation value was specified in accordance with domestic and foreign standards. Through the results of this study, it is judged that the safety of the gas engine power generation system can be improved and it can contribute to the commercialization of products.

Retrieval and Validation of Aerosol Optical Properties Using Japanese Next Generation Meteorological Satellite, Himawari-8 (일본 정지궤도 기상위성 Himawari-8을 이용한 에어로졸 광학정보 산출 및 검증)

  • Lim, Hyunkwang;Choi, Myungje;Kim, Mijin;Kim, Jhoon;Chan, P.W.
    • Korean Journal of Remote Sensing
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    • v.32 no.6
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    • pp.681-691
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    • 2016
  • Using various satellite measurements in UV, visible and IR, diverse algorithms to retrieve aerosol information have been developed and operated to date. Advanced Himawari Imager (AHI) onboard the Himawari 8 weather satellite was launched in 2014 and has 16 channels from visible to Thermal InfRared (TIR) in high temporal and spatial resolution. Using AHI, it is very valuable to retrieve aerosol optical properties over dark surface to demonstrate its capability. To retrieve aerosol optical properties using visible and Near InfRared (NIR) region, surface signal is very important to be removed which can be estimated using minimum reflectivity method. The estimated surface reflectance is then used to retrieve the aerosol optical properties through the inversion process. In this study, we retrieve the aerosol optical properties over dark surface, but not over bright surface such as clouds, desert and so on. Therefore, the bright surface was detected and masked using various infrared channels of AHI and spatial heterogeneity, Brightness Temperature Difference (BTD), etc. The retrieval result shows the correlation coefficient of 0.7 against AERONET, and the within the Expected Error (EE) of 49%. It is accurately retrieved even for low Aerosol Optical Depth (AOD). However, AOD tends to be underestimated over the Beijing Hefei area, where the surface reflectance using the minimum reflectance method is overestimated than the actual surface reflectance.

Comparative Analysis of the Kinematics of Types of Step during Blocking in Volleyball (배구 블로킹 시 스텝 방법에 대한 운동학적 비교 분석)

  • Jung, Ji-Un;Youm, Chang-Hong;Park, Young-Hoon;Park, Tae-Jin;Seo, Kook-Woong;Seo, Kook-Eun
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.73-83
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    • 2008
  • The purpose of this study was to investigate kinematic variables of three types of volleyball jump blocking motions through 3D video analysis. The subjects participated in this study were 7 male university volleyball players and 7 male physical education majors. 1. Regardless of blocking types, peak vertical velocity and jump height in the skilled group were faster and higher than the unskilled group. 2. The skilled group was flexed lower than the unskilled group at E2 of the hip, knee, and ankle joint during the cross over step blocking. 3. In all types of step, the peak angular velocity of the hip, knee, and ankle joint was showed at E2. 4. The skilled group was slower than the unskilled group at E2 of the angular velocity of the hip, knee, and ankle joint during cross over step blocking. In conclusion, the cross over step blocking in which the use of the upper extremities was relatively more available was effective to improve a defence skill for the jump height.

A Study on the Meaning and Prospect of the Certificate of Qualification in Private Security in Korea - Concerning the Enforcement of 2006' Examination - (민간자격증의 의의와 전망 -2006년 시험시행과 관련하여-)

  • Jeong, Ji-Woon
    • Korean Security Journal
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    • no.13
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    • pp.451-470
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    • 2007
  • This study is concerned Meaning of the certificate of qualification and Prospect of the certificate of qualification in private security in korea. Now, private security area is need the certificate of qualification, and the first examination in 2006' in Korea has meaning that open the period of the certificate of qualification. The 40 university(include colleges) applied the first examination. This exam is enforced 11. 25. 2006. in six part area in Korea. The 822 students are applied and 763 students(the ratio of successful applicants 92.8%) passed this exam. This apply exam is meaning the start of new development and specialization in private security area. I hope that this exam is a opportunity of cooperation between industry and the academic world. Also, this exam is a opportunity of student in private security are more hard training before take a job. As my understanding this exam is the confirmation by an authority, this exam is only neutral evidence to get the confidence and credit from the clients.

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Clinical Characteristics of Haenyeo with Depressive Disorders (해녀 우울장애 환자의 임상적 특징)

  • Park, Joon Hyuk;Jun, Byoung Sun;Lee, Chang In;Kim, Moon-Doo;Jeong, Ji Woon;Jung, Young-Eun
    • Korean Journal of Biological Psychiatry
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    • v.23 no.2
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    • pp.63-68
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    • 2016
  • Objectives Haenyeo are Korean professional women breath-hold divers in Jeju island. The aim of this study was to investigate the clinical characteristics of depressed Haenyeo group, compared to non-Haenyeo depressed group. Methods This study included 75 Haenyeo and 340 non-Haenyeo with depressive disorders recruited from the Dementia Early Detection Program in Jeju island. Structural diagnostic interviews were performed using the Korean version of Mini International Neuropsychiatric Interview. All patients completed the questionnaires, including the Subjective Memory Complaints Questionnaire (SMCQ), the Patient Health Questionnaire-15 (PHQ-15), and the Blessed dementia scale. Depression was evaluated by the Korean version of short form the Geriatric Depression Scale (K-SGDS) and cognition was assessed by the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) assessment packet. Results Although the mean scores of the K-SGDS were similar between Haenyeo and non-Haenyeo depressed groups, the Haenyeo group showed a higher mean score on the PSQ-15 (p < 0.001, ANCOVA adjusting for age, the K-SGDS and education). The Haenyeo group showed poorer performance on the Korean Version of Frontal Assessment Batter (p < 0.001), the Mini-Mental State Examination in the Korean version of the CERAD Assessment Packet (p < 0.018), the word fluency test (p < 0.001), and the word list memory test (p = 0.012) in ANCOVA adjusting for age and education. The mean SMCQ score was higher in the Haenyeo depressed group than in the non-Haenyeo depressed group. Conclusions The Haenyeo depressed group shows cognitive dysfunction, especially frontal lobe dysfunction, compared to the non-Haenyeo depressed group, indicating the Haenyeo depressed group may have more severe frontolimbic dysfunction due to chronic exposure to hypoxia. The Haenyeo depressed group suffers more somatic symptoms than the non-Haenyeo depressed group.

Antibacterial Effect of Bacteria Isolated from the Plant Rhizosphere against Pathogenic Bacteria of Fish (식물근권에서 분리한 세균의 어류질병세균에 대한 항균활성 효과)

  • Jeong, Ji-Woon;Park, So-Hyun;Kim, Dong-Hwi;Jeun, Yong-Chull;Heo, Moon-Soo
    • Journal of Life Science
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    • v.24 no.7
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    • pp.757-761
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    • 2014
  • Olive flounder (Paralichthys olivaceus) is an important aquaculture fish species in Jeju Island, South Korea. Due to the intensification of flounder fish farming, huge amounts of chemical antibiotics are used against several fish diseases. This has many harmful side effects on fish, as well as human consumers. Hence, an alternative to chemical antibiotic agents is needed for disease control. In this study, three strains of rhizobacteria (BRH433-2, TRH415-2, and THJ609-3) were isolated from the rhizosphere of plants. Assays of their antibacterial activity against fish pathogens, such as S. iniae, S. parauberis, V. anguillarum, and E. tarda, were performed with untreated broth culture (without cell separation), supernatant, and precipitated pellets separated by centrifugation. Among these, the cell suspension prepared from the precipitated pellet showed significant antimicrobial activity when compared with that of the untreated broth culture and centrifugal supernatant. These results indicate that the three isolated rhizobacterial strains exhibit antibacterial activity. Analysis of the 16S rDNA sequences of the BRH-433-2, THJ609-3, and TRH415-2 strains showed the highest similarity to Burkholderia gladioli (99.5%), Pseudomonas baetica (97.7%), and P. koreensis and P. baetica (98.4%), respectively. We suggest that the strains hold promise in disease management of fish.

Effects of Dementia Experience using Virtual Reality on Public Awareness and Attitude toward Dementia Patients (3D 가상치매체험 프로그램이 치매에 대한 태도와 인식변화에 미치는 효과)

  • Jeong, Ji Woon;Kim, Hyun Taek;Park, June Hyuk
    • Journal of the HCI Society of Korea
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    • v.13 no.4
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    • pp.5-14
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    • 2018
  • The Empathy for Dementia using Virtual Reality (EDuVR) system, developed by the Jeju Provincial Dementia Center, is a 3D video system capturing the experience of dementia in a first-person perspective using 360 degree vritual reality (VR) technology. It was developed to create a greater understanding of dementia and to help people empathize with individuals with dementia through an immersive VR experience. The EDuVR shows how a dementia patient has impairments in memory, orientation, language, judgment and problem solving, as well as problems with activities of daily living. The present study reported the effectiveness of the EDuVR experience in changing public awareness of, and attitude toward, dementia. Sixty-six participants were assigned to the EDuVR (n = 34) or the conventional education (n = 32) groups, and two types of questionnaires - attitude and awareness questionnaires - were administered to the subjects before and after the EDuVR experience or education. The simulator sickness and presence questionnaires were administered to the EDuVR group to assess cybersickness and presence of the VR experience. As a results, the attitude and awareness toward dementia patients changed positively in both the EDuVR and the conventional education groups, and these changes did not differ between two groups. Only one person reported a significant level of cybersicness after experiencing the EDuVR system. These results suggest that the EDuVR enhances the level of understanding and empathy for dementia and would be a useful tool for improving awareness in the general public.

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Comparison Study on the Blood Acetaldehyde Concentration According to ALDH2 Genotype, Age, Gender (ALDH2 유전자형에 따라 나이, 성별로 나누어 비교한 혈중 아세트알데히드 농도에 관한 연구)

  • Byung-Uk Joo;Ji-Woon Jeong;Se Ra Choi;Jung Seok Lee;Sung Young Huh;Hyeon-Kyeong Kim;Sung-Gon Kim
    • Korean Journal of Biological Psychiatry
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    • v.31 no.1
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    • pp.1-6
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    • 2024
  • Objectives Alcohol is metabolized to acetaldehyde by alcohol dehydrogenase enzyme in the liver and then acetaldehyde is metabolized to acetone by aldehyde dehydrogenase (ALDH) in the liver. There are two main ALDH enzymes which metabolize the acetaldehyde produced during ethanol oxidation. In particular, in the presence of the ALDH2 1*2 allele, the activity of the ALDH 2 enzyme is lowered. As a result, acetaldehyde metabolism is slowed down and acetaldehyde accumulates in the body compared to the ALDH2 1*1 allele. There are many studies that have investigated the blood acetaldehyde concentration according to the ALDH2 genotype, but there are few studies to compare this with age. So we investigated the blood acetaldehyde concentration according to ALDH2 genotype, age and gender. Methods According to the ALDH2 genotype, we divided the group by gender and age. We divided the age group in to three groups which ranged from 20 to 34 years old, from 35 to 49 years old, and lastly from 50 to 64 years old. And then we collected blood samples after 15 min, 30 min, 1 hr, 2 hr, 3 hr, 4 hr, 5 hr and 15 hr of after drinking to measure the blood acetaldehyde concentration. Results In ALDH2 1*2 allele group, there are significant differences of the blood acetaldehyde concentration between the age groups. In ALDH2 1*2 allele and male group, there are significant differences of the blood acetaldehyde concentration between the age groups. Conclusions There are significant differences of the blood acetaldehyde concentration between the age groups according to ALDH2 genotype. Also, there are significant differences of the blood acetaldehyde concentration between the age groups with male gender and ALDH2 1*2 allele. Studies about other factors that may influence the blood acetaldehyde concentration are needed.

Implementation of Behavior Notification System for Guide Dog Harness Using IMU and Accelerometer Sensor (IMU 및 가속도 센서를 이용한 안내견 하네스 행동 알림 시스템 구현)

  • Ahn, Byeong-Gu;Noh, Yun-Hong;Jeong, Do-Un
    • Journal of the Institute of Convergence Signal Processing
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    • v.16 no.1
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    • pp.15-21
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    • 2015
  • In this paper, a behavior notification system of the harness of a guide dog is implemented for a blind person to get helps for environmental and situational awareness while walking with the guide dog. IMU modules is attached on the guide dog's harness saddle and the acceleration sensor belt is mounted on its thigh. Gait estimation and behavior judgement are performed by recording and analyzing the outputs of the sensors. Performance analysis for seven different kinds of behaviors has been done. The seven different behaviors, which the guide dog recognizes, are descending stairs, climbing stairs, uphill, downhill, stop, flat road, and selective disobedience. Results for the performance analysis show that the average success rate of the behavior rule estimation of harness of the guide dog is 92.78% and the behavior notification system can be effectively used in real situations.