• 제목/요약/키워드: IT839

검색결과 310건 처리시간 0.038초

한강하구 퇴적물의 생지화학적 반응에 관한 연구 (A Study on the Biogeochemistry of the Sediments in the Han River Estuary)

  • 임보미;기보민;최정현
    • 대한환경공학회지
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    • 제31권10호
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    • pp.839-844
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    • 2009
  • 이 연구는 담수 퇴적물에서 주되게 일어나는 탈질(denitrification), 철 환원(iron reduction), 메탄 환원(methanogenesis) 반응이 퇴적물 유기물 분해에서 차지하는 중요도를 파악하였다. 탈질률, 철환원률, 메탄환원률 모두 식물이 존재하지 않는 Site A, 새섬매자기 군락이 서식하는 Site B, 갈대 군락이 서식하는 Site C에서 통계적으로 유의한 차이를 보였고(P < 0.05), 퇴적물 깊이에 따라서는 메탄환원률만이 유의한 차이를 보였다. 유기물 함량은 Site A, Site B, Site C 순으로 식물의 존재와 밀도 증가에 따라 증가하였다. Site A가 가장 낮은 유기물 함량을 나타냄에도 불구하고 가장 높은 탈질률과 철환원률을 나타내었고, 메탄환원률의 경우 Site C에서 가장 큰 값을 나타내었다. 유기물의 혐기성 분해가 주로 탈질, 철 환원, 메탄 환원에 의해 일어난다고 가정한다면, 한강하구의 경우 탈질이 유기물을 분해하는 가장 주된 반응임을 알 수 있었다.

시범영양사업지역 주민들의 영양실태조사 보고 (The Nutritional Status of Various Populations Living in Selected Areas for Model Nutritional Work in Korea)

  • 신애자;계승희;김동연;이행신
    • 대한지역사회영양학회지
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    • 제4권4호
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    • pp.529-538
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    • 1999
  • It is very important to collect information on the nutritional status of the Korean population for the development of health promotion programs including nutrition. The purpose of this study was to assess the nutritional status of various population living in selected areas for model nutritional work. Seven hundred eighty households(30 households per each area)from 26 areas participated in this study from November 1 to November 20, 1996. Dietary intake data for two consecutive days were collected at household level by a weighting method. The mean energy intake of the subjects(1,934kcal) was higher than that resulted from the ‘95 Korean National Nutrition Survey(1,839kcal). The proportion of energy derived from cereals was 60.1%. The proportion of total protein intake from animal sources was 49.4%. These results were similar to those found in the ‘95 Korean National Nutrition Survey. Most nutrients(except iron, thiamin, riboflavin, vitamin C, and crude fiber) were higher than the result of the ‘95 Korean National Nutrition Survey. However, the average iron intake was about 68% of the result of ‘95 Korean National Nutrition Survey. This may be due to the adjustment of iron content in rice(3.7mg/100glongrightarrow0.5mg/100g) included in nutrient database for calculating nutrient intakes. The mean energy contribution from carbohydrate, protein, and fat were 64.2%, 16.4% and 19.4%, respectively. Significant differences of nutrient intakes were noted among some areas, which may be due to different food intake patterns according to the needs of the particular area. Therefore, the result of this study indicates that there are significant differences in food and nutrient intakes among the areas, suggesting that nutritional improvement programs may need to be developed differently by areas.

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초등학교 비만아동 및 정상체중아동의 식행동과 어머니의 식행동 지도 (The Dietary Behavior of Obese and Normal Weight Elementary School Children with Maternal Guidance for Their Dietary Behavior)

  • 이혜상;정운선;박응임
    • 대한지역사회영양학회지
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    • 제8권6호
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    • pp.831-839
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    • 2003
  • This study was conducted to investigate whether there were any differences in the body image perception, dietary behavior and maternal dietary guidance between an obese group (“OG”) and a normal weight group (“NWG”), and furthermore, to provide basic informations for comprehensive educational programs for obese children. For this purpose, the questionnaire method was used. The subjects were 1,501 elementary school children, in the 4th to the 6th grades in Seoul, Busan, Daegu, Gwangju, and Andong, and their mothers (1,459). The percentage of the children who misperceive their body image was higher among the girls (30.4%) than the boys (22.6%) The average scores for balanced dietary behavior as assessed by the children was higher in the OG than in NWG; the average scores for dietary control as assessed by their mothers was higher in the NWG than in the OG. The scores for dietary behavior as assessed by the children was different from those as assessed by their mothers. Assuming that the mothers would give more correct and balanced answers, the development of a reliable questionnaire for dietary behavior that could be more accurately answered by the children is necessary. Maternal dietary guidance for dietary control was more frequently given in the OG as compared with the NWG and more frequently in girls as compared with boys ; while that for balanced diet was more in the NWG as compared with the OG. The worse the mothers estimate of the dietary behavior for their children, the more they tried to guide their children in dietary behavior. It is recommended that the children should be taught to correctly recognize the degree of their obesity, and receive the appropriate educational program accordingly, including the maternal dietary guidance.

프랙탈을 이용한 ZnO 바리스터 표면 구조 및 전기적 특성 (The Structure and Electrical Characteristics of ZnO Varistors Surface using-Fractal)

  • 오수홍;홍경진;이진;이준웅;김태성
    • 한국전기전자재료학회논문지
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    • 제13권10호
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    • pp.834-839
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    • 2000
  • The structural properties that SEM photograph of ZnO varistors surface studied by fractal mathematics program were investigated to verify the relations of electrical characteristics. The SEM photograph of ZnO varistors surface were changed by binary code and the grain shape of that were analyzed by fractal dimension. The void of ZnO varistors surface was found by fractal program. The relation between grain density and electrical properties depend on fractal dimension. The grain size in ZnO varistors surface was decreased by increasing of Sb$_2$O$_3$ addition. The spinel structure was formed by Sb$_2$O$_3$addition and it was depressed the ZnO grain formation. The grain size of ZnO by Sb$_2$O$_3$addition were from 5 to 10[${\mu}{\textrm}{m}$]. Among of ZnO varistors, fractal dimension of ZnO4 was very high as a 1.764. The density of grain boundary in ZnO2 and ZnO3 varistors surface was 15[%] by formed spinal structure. The breakdown electric field of ZnO2 that fractal dimension has 1.752 was very high to be 8.5[kV/cm]. When the fractal dimensin was high, the grain shape of ZnO varistors was complex and the serial layers of ZnO grain was increased.

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μ-PD법을 이용하여 성장시킨 Er2O3와 MgO를 첨가한 화학양론조성 LiNbO3 단결정의 Up-conversion 특성 (Up-conversion Property of Er2O3 and MgO Co-doped Stoichiometric LiNbO3 Single Crystal by Using the μ-PD Method)

  • 서중원;전원남;이성문;양우석;이한영;윤대호
    • 한국세라믹학회지
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    • 제39권9호
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    • pp.835-839
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    • 2002
  • Micro-Pulling Down(${\mu}$-PD)법을 이용하여 직경 1 mm, 길이 30∼35 mm의 $Er_2O_3$와 MgO가 첨가된 화학양론조성 $LiNbO_3$단결정을 성장하였다. 성장된 결정의 $Er_2O_3$와 MgO 첨가에 따른 up-conversion 특성의 변화 및 MgO 첨가량이 광손상에 미치는 영향을 관찰하기 위해 투과율을 측정하였다. 또한 $LiNbO_3$ 단결정 내의 결함유무를 광학현미경을 이용하여 관찰하였고, Electron Probe Micro Analysis(EPMA)를 이용하여 결정 내에 $Er_2O_3$와 MgO가 균일하게 분포되어있음을 확인하였다.

무선 센서 네트워크에서 효율적인 에너지 관리를 위한 분산형 클러스터링 알고리즘 설계 (Design of Dispersed Clustering Algorithm for Efficient Energy Management in Wireless Sensor Network)

  • 전민호;강철규;오창헌
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2011년도 추계학술대회
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    • pp.839-842
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    • 2011
  • 최근 무선 센서노드의 에너지 제약을 해결하기 위해 에너지 하비스팅 기반 무선 센서 네트워크에 대한 연구가 활발히 진행되고 있다. 에너지 하비스팅 기반 무선 센서 네트워크는 태양열, 풍력, 지력 에너지 등의 환경 에너지를 센서 노드의 전력으로 사용하여 노드의 생존 시간을 향상시키는 기술이다. 이러한 에너지 하비스팅 환경에서 기존의 에너지가 제약된 환경을 배경으로 개발된 라우팅 프로토콜을 사용할 경우, 하비스팅 장치로부터 축적되는 에너지가 경로 설정 시 반영되지 않는 문제점이 발생한다. 또한 분산되지 않은 경로들은 네트워크의 수명을 단축하게 된다. 따라서 본 논문에서는 각 노드간의 경로를 분산시키는 알고리즘을 제안한다. 시뮬레이터를 통해 제안하는 알고리즘을 사용했을 경우 노드의 경로가 다양하게 반영되는 것을 보여주었다.

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슬림형 광 디스크 드라이브의 축방향 진동에 대한 실험적 해석 (Experimental Analysis of Axial Vibration in Slim-type Optical Disc Drive)

  • 박대경;전규찬;이성진;장동섭
    • 한국소음진동공학회논문집
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    • 제12권11호
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    • pp.833-839
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    • 2002
  • As the demand for slim laptops requires low-height optical disc drives, vibration problems of optical disc drives are of great concern. Additionally, with the decrease of a track width and a depth of focus in high density drives, studies on vibration resonance between mechanical parts become more important. From the vibration point of view, the performance of optical disc drives is closely related with the relative displacement between a disc and an objective lens which is controlled by servo mechanism. In other words, to read and write data properly, the relative displacement between an optical disc and an objective lens should be within a certain limit. The relative displacement is dependent on not only an anti-vibration mechanism design but also servo control capability. Good servo controls can make compensation for poor mechanisms, and vice versa. In a usual development process, robustness of the anti-vibration mechanism is always verified with the servo control of an objective lens. Engineers partially modify servo gain margin in case of a data reading error. This modification cannot correct the data reading error occasionally and the mechanism should be redesigned more robustly. Therefore it is necessary to verify a mechanism with respect to the possible servo gain plot. In this study we propose the experimental verification method for anti-vibration mechanism with respect to the existing servo gain plot. Thismethod verifies axial vibration characteristics of optical disc drives on the basis of transmissibility. Using this method, we verified our mechanism and modified the mechanism for better anti-vibration characteristics.

The reliability test of a smart insole for gait analysis in stroke patients

  • Seo, Tae-Won;Lee, Jun-Young;Lee, Byoung-Hee
    • 대한물리치료과학회지
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    • 제29권1호
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    • pp.30-40
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    • 2022
  • Background: This study analyzed the reliability of smart guides for gait analysis in patients with stroke. Design: Cross-sectional study. Methods: The participants of the study were 30 patients with stroke who could walk more than 10 m and had an MMSE-K test score of ≥24. Prior to the experiment, the subjects or their guardians entered their demographic characteristics including gender, age, height, weight into the prepared computer. The experiment was conducted in a quiet, comfortable, and independent location, and the patient was reminded of the equipment description, precautions, and safety rules for walking. A smart insole was inserted into the shoes of the patients and the shoes were put on before the patients walked three times on the 5-m gait analysis system mat installed in the laboratory. Results: The reliability of the equipment was compared with that of the gait analysis system, and the results of this study are as follows: among the gait analysis items, velocity had an ICC=0.982, the cadence had an ICC=0.905, the swing phase on the side of the gait cycle had an ICC=0.893, the swing phase on the side of the gait had an ICC=0.839, that on the non-affected side had an ICC=0.939, single support on the affected side had an ICC=0.812, and support on the non-affected side had an ICC=0.767. Conclusion: The results of this study indicate no statistical difference between the smart insole and the gait analysis system. Therefore, it is believed that real-time gait analysis through smart insole measurement could help patients in rehabilitation.

컴퓨터기반시험에 대한 한의과대학 학생들의 인식 및 만족도 조사 (A Survey on the Perception and Satisfaction of Korean Traditional Medical Students on Computer-Based Test)

  • 김미경;한창호
    • 대한예방한의학회지
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    • 제25권3호
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    • pp.57-71
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    • 2021
  • Objectives : Computer-based test (CBT) will be introduced in the national examination of Korean medicine doctors from 2023. This study was aimed to provide some information, including prior considerations, to those preparing for CBT, by presenting a summary of the survey results from participants in a CBT simulation test. Methods : In December 2020, applicants from the graduating class of the college of Korean medicine from four universities participated in the simulation test for CBT. An online anonymous survey on the applicants' preference for CBT versus paper-based tests (PBT) was conducted. The questionnaire consisted of multiple-choice questions on a 5-point Likert scale and free-form questions. Results : A total of 176 students responded to the survey. Their response to CBT was generally positive. The item with the highest agreement was that it should provide a sufficient opportunity to experience CBT in the undergraduate exam (4.38±0.839). Concerns about the possibility of cheating or poor concentration were also detected. In addition to guaranteeing the stability of the CBT system, there were many comments expressing the need to supplement functions within the CBT system, including the memo or highlighter function. Conclusions : This study confirmed the feasibility of CBT including multimedia questions in the field of Korean medicine education and identified overall positive responses from those who experienced the CBT simulation test. Although time is short and there is so much to prepare, we hope this will be a leap forward for effective educational innovation in line with the changing environment of the health care education field.

Assessing the Formation of Polycyclic Aromatic Hydrocarbons in Grilled Beef Steak and Beef Patty with Different Charcoals by the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) Method with Gas Chromatography-Mass Spectrometry

  • Ali Samet Babaoglu
    • 한국축산식품학회지
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    • 제43권5호
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    • pp.826-839
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    • 2023
  • This study investigated the effects of different charcoals on the occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in grilled beef steaks and beef patties. Seven different charcoals were used as follows: from oak wood (C1), from orange wood (C2), from Valonia oak wood (C3), from Marabu wood (C4), extruded charcoal from beech wood (C5), from coconut shells (C6), and from hazelnut shells (C7). The grilling times for each charcoal type were 6 min for the beef patties and 7 min for the beef steaks, until the internal temperature reached at least 74℃. The total concentration of 16 PAHs (PAH16) in beef steaks grilled with C1 (35.75 ㎍/kg) and C7 (36.39 ㎍/kg) was higher than that of C3 (23.80 ㎍/kg) and C6 (24.48 ㎍/kg; p<0.05). The highest amounts of PAH16 (216.40 ㎍/kg) were determined in the beef patty samples grilled using C5 (p<0.05). The summation of benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene, referred to as PAH4, was not detected in any of the beef steaks, whereas it was determined in the beef patties grilled with C2 (7.72 ㎍/kg) and C5 (22.95 ㎍/kg; p<0.05). The PAH16 concentrations of the beef patty samples in each charcoal group were significantly higher compared to the beef steaks (p<0.05). To avoid the formation of high PAH levels, the use of extruded charcoal and hazelnut shell charcoal should therefore be avoided when charcoal grilling beef steaks and beef patties, and low-fat meat products should be preferred.