• 전자공학회논문지CI
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• 제44권1호
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• pp.41-48
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• 2007

본 논문은 2.4GHz 무선 채널 특성을 가진 센서 노드의 손실 없는 데이터 전송을 위한 최적의 배치 방법을 제안한다. 제안한 방식은 무선 환경에서 log-normal path loss 모델을 구성하여 최적의 송수신 거리를 결정하고, 센서 노드의 밀도 계산을 통해서 최적의 센서 노드 개수를 구한다. 데이터 손실이 없는 전송을 위해 송수신 가능 거리와 센서 노드의 개수를 이용하여 공간에 최적으로 배치할 수 있는 위치를 SOM(Self-Organizing Feature Maps)으로 탐색한다. 논문에서 실험한 건물에서는 센서노드의 송수신 거리는 20m이고, 최적의 센서 노드 개수는 8개가 되었으며, 시뮬레이션을 통해서 센서 노드의 최적의 위치 탐색과 센서 노드의 연결 상태를 확인하였다.

• 대한조선학회논문집
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• 제51권6호
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• pp.489-494
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• 2014

Estimation of correct ice load under various operating conditions is important during the design and the operation stages of an icebreaker. Normal operating conditions are expected from the official field ice trials and also from general ice transit action. In this paper ice load for the Korean icebreaking research vessel, ARAON, under normal operating condition, is discussed. Published ice load data from full-scale sea trials of six icebreakers were analysed to derive an empirical ice load prediction formula. The IBRV ARAON had sea ice trials during 2010 and 2012 summer season. Strain gauge signal were recorded during her icebreaking voyage and the measured strain data were converted to the equivalent hull stress values. The effect of ARAON's speed in ice and the hull stresses are investigated. By comparing the empirical formula and ice load calculation based von measured data, it is recommended to use the empirical ice load estimation formula for the initial design stage.

• 한국대기환경학회지
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• 제31권5호
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• pp.461-471
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• 2015

Base on emission factors derived from National Institute of Environmental Research, Particulate matter from combined cycle power plants (CCPPs) has been estimated to be a important source of $PM_{10}$. Generally there is no serious emission of particulate matter in CCPPs. because the fuel of them is natural gas. But emission gas after long shut down season has very high dust content. Therefore $PM_{10}$ emission rate is dependent on its operation mode. In this study, particulate dispersion study for new city near CCPPs complex has performed using CALPUFF model for three case. $PM_{10}$ concentration has big difference between normal operation and 2 case start-up condition after long shutdown. In normal operating conditions, daily $0.32{\sim}0.50{\mu}g/m^3$ influence on of the surrounding area. But when 1~2 aerobic high concentration discharged conditions, average concentration is higher about $9.2{\sim}34.1{\mu}g/m^3$ than normal operating conditions.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.534-537
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• 2005

Free Vibration Analysis using Non-dimensional Dynamic Influence Function (NDIF) is extended to arbitrarily shaped plates including polygonal plates. Since the corners of polygonal plates have indefinite normal directions and additional boundary conditions related to a twisting moment at a corner along with moment and shear force zero conditions, it is not easy to apply the NDIF method to polygonal plates wi th the free boundary condition. Moreover, owing to the fact that the local polar coordinate system, which has been introduced for free plates with smoothly varying edges, cannot be employed for the straight edges of the polygonal plates, a new coordinate system is required for the polygonal plates. These problems are solved by developing the new method of modifying a corner into a circular arc and setting the normal direction at the corner to an average value of normal direct ions of two edges adjacent to the corner. Some case studies for plates with various shapes show that the proposed method gives credible natural frequencies and mode shapes for various polygons that agree well with those by an exact method or FEM (ANSYS).

• Journal of Acupuncture Research
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• 제20권4호
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• pp.1-10
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• 2003

Objective: The purpose of this study was to determine the effects of Puerariae radix(PR) herb-acupuncture on nitric oxide synthase(NOS) expression in hippocampus of alcohol-intoxicated Sprague-Dawley(SD) rats. Methods: SD rats were randomly assigned into 6 groups; normal group, control group, alcohol with herb-acupuncture group(0.3, 3, 30 and 300mg/kg PR). Normal groups were received with NaCl, while alcohol intoxication groups were injected intraperitoneally with alcohol(2g/kg) twice per day for 3 days. Herb-acupuncture groups were injected on Zhongwan(CV12) for 5 consecutive days. For the detection of NADPH-d-positive cells in hippocampus, immunohistochemistry was performed. Results: n control group, a significant decrease in NADPH-d-positive cells was observed compared to normal group. In alcohol with herb-acupuncture group, NADPH-d-positive cells increased significantly compared to control group. Conclusions: The present results revealed that NOS expression is enhanced in the hippocampus of SD rats through PR herb-acupuncture in an acute alcoholic intoxication condition.

• 음성과학
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• 제15권3호
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• pp.67-78
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• 2008

This study was intended to analyze how well people with right hemisphere damage can understand Korean proverbs. This study used a between-subject design and within-subjects design where all subjects participate in the three experiments for 10 hospitalized patients of whose average age is 66.1 years old and 10 normal adults in the same age range. Experiment 1 was to make up Korean proverb related stories and suggest it in written, Experiment II was to suggest a picture presenting a Korean proverb and the proverb itself directly, and Experiment III was to make up a story related to a Korean proverb and tell it auditory. Five Korea proverbs were used for each experiment; 15 in total. The results were as follows: First, there was a significant difference in understanding of Korean proverbs between normal adults and people with right hemisphere damage. Second, there was no significant difference of understanding between them by stimulating methods to suggest Korean proverbs. Third, people with right hemisphere damage had a tendency to interpret Korean proverbs literally as a total wrong reaction was composed of 55.36%. Considering the above the results, it can be said that people with right hemisphere damage have less understanding of Korean proverbs than normal adults, which is not affected by a way of or a condition of suggesting Korean proverbs in people with RHD, and they are inclined to make literal interpretation of Korean proverbs as they are.

• 대한기관식도과학회지
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• 제7권2호
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• pp.161-167
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• 2001

Background and Objectives： Total laryngectomy is often required for advanced cases. But this operation induced the many inconvenience of basic daily life. Early diagnosis of laryngeal cancer is very important to prevent from this disastrous condition. In this point of view, mass screening test for early detection of laryngeal cancer is necessary. Screening test using voice has many advantages such as simple, less interventional. Voice collection by Automatic Response System(ARS) is comfortable and easy to got acoustic sample. Thus author tried to got the acoustic parameters which can differentiate normal, benign. and malignant laryngeal diseases and also checked the availability of parameters on neural network system. Materials and Methods: Author has evaluated the voice from 17 laryngeal cancer patients and 45 benign laryngeal disease patients who visited at Department of Otolaryngology, Pusan National University Hospital from May 1998 to April 2001, and 15 normal control. Author chose the sir Parameters (Jitt. vFo, Shim, vAm, NHR, SPI) that was thought to be related with voice collected by ARS among thirty-three parameters analysed by a Multi-Dimensional Voice Program (MDVP). Two-step neural network was used for the availability of six parameters. Results: The detection rate of normal voice by ARS voice analysis is 78.5% and detection rate of abnormal voice was 97.1 o/o. Among abnormal voice, the detection rate of benign laryngeal diseases and laryngeal cancers were 82.4 o/o, 70.6% respectively. Conclusion: Author concluded that six parameters and Matlab based neural network software may be effective in development of acoustic screening system for laryngeal cancer and further study should be necessary for development of new acoustic parameters.

• 말소리와 음성과학
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• 제6권3호
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• pp.91-99
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• 2014

Although it is well documented that patients with cochlear implant experience hearing difficulties when processing their first language, very little is known whether or not and to what extent cochlear implant patients recognize segments in a second language. This preliminary study examines how Korean learners of English identify English segments in a normal hearing and cochlear implant simulation conditions. Participants heard English vowels and consonants in the following three conditions: normal hearing condition, 12-channel noise vocoding with 0mm spectral shift, and 12-channel noise vocoding with 3mm spectral shift. Results confirmed that nonnative listeners could also retrieve spectral information from vocoded speech signal, as they recognized vowel features fairly accurately despite the vocoding. In contrast, the intelligibility of manner and place features of consonants was significantly decreased by vocoding. In addition, we found that spectral shift affected listeners' vowel recognition, probably because information regarding F1 is diminished by spectral shifting. Results suggest that patients with cochlear implant and normal hearing second language learners would experience different patterns of listening errors when processing their second language(s).

• 대한치과교정학회지
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• 제20권2호
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• pp.409-417
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• 1990

Tooth movement would be impeded by frictional force arised between archwire and tube, bracket or elastics in the fixed orthodontic appliances, which could be changed variably by such several factors as the contact area, normal (perpendicular) force and the condition of contact surface. There were many literatures about frictional force in the orthodontic region, but different results were obtained from little controlled research so that was very difficult in clinical application. Therefore we have reviewed comprehensively previous literatures about frictional force and thus several results were obtained as follows: 1. For use species of the orthodontic wire, frictional force was influenced mainly by surface roughness of wire in the absence of binding, while that was influenced mainly by normal force in high binding angulation. 2. For the cross-section and diameter of the wire, the contact area influenced mainly on frictional force in the absence of binding, while wire stiffness influenced mainly on frictional force in high binding angulation. 3. The greater the bracket width, the greater frictional force, and frictional force of the plastic bracket was larger than that of the metal bracket. 4. For ligation type, frictional force of the stainless steel ligation was larger than that of the elastic ligation, and frictional force was directly proportional to ligation force. 5. Variable frictional force were occured from the saliva combined with such another factors as normal force and mode of surface oxide et al.

• 한국자원식물학회지
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• 제11권2호
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• pp.188-194
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• 1998

This experiment was conducted to introduce phosphinothricin acetyl -transferase(PAT) gene, resistant to basta and non-selective herbidide, into tobacco(Nicotiana tabacum cv.BY4). For shoot formation,tobacco leaf disks were placed on the MS medium supplemented with 2.0mg/L BA and 0.1mg/L NAA. In this medium condition, tobacco leaf disces were cocultivated with A. tumefaciens MP90 containing NPT IIand PAT resistant to kanamycin and Basta, respectively. Shoots were obtained in the medium containing antibiotics, and those were transferred to rooting medium supplemented with 0.1mg/L NAA and antibiotics. The plants obtaining roots were transplanted into soil. Phenotype of transgenic tobacco plant was mostly as normal plant. However, about 5% was abnormal plant, which did not set seeds. PCR analysis and southern blot were performed to determine transformation. As the results, it was confirmed that PAT gene was stably integrated into tobacco genome.When herbicide, basta, was sprayed to the plants confirmed by PCR, the transgenic plants showed normal growth, whereas normal plants died. Therefore, the result of this experiment show that tobacco transformation for the resistance to basta, non-selective herbicide, was successful because PAT gene was stably integrated into tobacco.