Pekeris 도파관에서 음선 접근법을 이용한 지면파 해석

최지웅,Choi, Jee-Woong 한국음향학회 2009 韓國音響學會誌 Vol.28 No.3

지면파는 해저면 음속이 깊이에 따라 일정할 경우 해저면 음속으로 진행하는 음파로 일반적으로 모드분산으로부터 설명된다. 모드분산은 도파관의 기하학적 구조에 의한 음파의 반사 및 굴절에 의해 발생되므로 본 논문에서는 지면파를 음선이론에 기초하여 모의하였다. 지면파는 일련의 선두파들의 조합으로써 해석될 수 있으므로 [Choi와 Dahl, J. Acoust. Soc. Am. 119, 3660-3668 (2006)], 음선 접근법을 이용하여 시간영역에서 여러 경로로 전파되는 선두파들의 채널 임펄스 응답과 선두파 신호의 컨볼루션을 취하여 지면파를 모의한다. 모의된 지면파는 광대역 시간영역 포물선 방정식 기법을 이용하여 모의된 지면파와 비교, 검증된다. Ground wave is an acoustic wave propagating at a sediment sound speed in the case that sediment sound speed is constant with depth, which is explained by modal dispersion effects. In this paper, the ground wave in time domain is simulated using the ray-based approach, which is possible because the modal dispersion can be explained by the guiding of energy caused by reflection and refraction in the waveguide geometry. For a Pekeris waveguide, the ground wave can be interpreted as a sequence of head waves, called a head wave sequence [Choi and Dahl, J. Acoust. Soc. Am. 119, 3660-3668 (2006)]. The ground wave is simulated by convolution of the source signal with a channel impulse response of the head wave sequence, which is compared with simulated signals obtained via a Fourier synthesis of a complex parabolic equation (PE) field.

1910년대 조선에서 자유주의의 두 가지 유형과 성격

최선웅(Choi, Sun?woong) 호서사학회 2015 역사와 담론 Vol.0 No.75

응급실내에서 발생한 폭력의 실태

최웅지,조남수,조수형,김성중,박광철,박진실 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Background and Objectives: The objective of this study was to obtain circumstances about violence providers and cause of the violence in emergency room. Materials and Methods: Reports were provided to emergency department doctors, nurses and emergency medical technicians working in Chosun University Hospital Emergency Center during the sixty days from 26 May 2003 to 24 July 2003. Report form consisted of the degree of violence, the reason for the violence, dermographic information about violence providers, outbreak time of violence and response of emergency personnels. Results: SixtyUeight case of violence in the emergency department were reported. Almost all of the violence was due to the male gender and high incidence in third and fourth decade. The violence occured mostly in the night shift. 55.9% of violence was done by patient and 41.2% was done by patient's guardians. The leading cause of violence were alcohol drunken and delay of laboratory test and treatment. Verbal abuse and threats were the most concern form of violence, Conclusion: It is necessary to solve the problems faced in the emergency department not only administrative and financial aid but also regular preventive education and further study.

맞벌이 여부에 따른 직장-가정간 갈등과 직무만족도

최수찬,우종민,박웅섭,김상아 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.1

목적 본 연구에서는 기혼의 직장인들을 대상으로 직장 역할에 참여함으로서 가정역할 수행이 어려운 경우와 반대로 가정역할에 참여함으로서 직장 역할 수행이 어려운 경우에 발생하는 직장-가정 간 갈등과 같은 스트레스가 직무태도에 미치는 영향에 있어 맞벌이 여부에 따른 차별적 영향의 가능성을 고찰해보고자 하였다 방법 서울과 수도권에 거주하고 있는 직장인 1,000명을 대상으로 우편설문을 실시하여 44.0%의 회수율을 보였으며 본 연구의 주제인 맞벌이 여부에 맞도록 기혼상태로 보고한 236부의 설문지만을 최종 자료로 사용하였다 수집된 자료는 전산입력 후 SAS 10.0 프로그램을 사용하여 통계처리 하였다 결과 직무만족도를 종속변수로 이변량분석에서 유의한 변수들을 독립변수로 한 다중희귀분석수행결과 홑벌이에 있어서는 직장이 가정에 끼치는 갈등이 감소할수록 직무만족도가 유의하게 높았고(p<0.05) 맞벌이에서는 가정이 직장에 끼치는 갈등이 감소할수록 직무만족도가 유의하게 높았다(p<0.05) 결론 맞벌이 여부에 따라 경험하는 직장-가정과 관련된 스트레스의 내용에 차이가 있으므로 추후 기업 내에서 근로자들의 직무만족도를 향상시키기 위해서는 홑벌이와 맞벌이와 같은 가족형태에 따른 차별적 서비스를 제공할 필요가 있다 Objectives Work family conflict can arise from two opposite directions the experiences at work interfere with family life and the experiences in the family interfere with work life This study explored the effects of the presence of two income sources on the association between work-family conflict and Job attitude Methods Responses to structured survey questionnaires were received from 236 two-income families living in the Seoul Metropolitan Area Results A differential effect was observed between single income families and two-income families Higher job satisfaction was related with lower work interference with family (WIF) among single-income families and with lower family interference with work (FIW) among two-income families Conclusions Employee welfare programs need to be expanded to enhance job satisfaction for the increasing number of two-income families

陶淵明 田園詩의 美的體驗에 대하여

崔雄赫 대구효성 가톨릭대학교 1994 연구논문집 Vol.48 No.1

골프스윙에서의 운동역학적 변인비교 분석

최웅재 한국학교체육학회 2001 한국학교 체육학회지 Vol.11 No.1

The purpose of this study was to analyze and compare kinematic variables between the pc golfer and amateur golfer and suggest kinematic principle of golf swing. The next followings are the conclusion of this research. 1) You can tell pc golfer angles are opened than the amateur golfer at the impact. 2) The speed of pc golfer's swing, right before the impact was 45.84±3.3m/s, and for amateur golfer was 36.54±1.9m/s. You could tell that pro golfer's right before the impact was faster. 3) You could tell that pro golfer's hitting point are more center than the amateur golfer from the impact. 4) The back spin of the ball was more higher than amateur golfer, and the side spin was not happened. 5) Looking at out side target after impact, pro golfer was more accurate than golfer.

키토산을 첨가한 콤포짓트 레진의 기계적 성질과 항균성에 관한 연구

최낙찬,모웅남,이용준 조선대학교 구강생물학연구소 2003 口腔生物學硏究 Vol.27 No.1

The purpose of this study was to evaluate the mechanical and anti-microbial properties of newly prepared chitosan G for human gingival fibroblast. Compressive strength, diametral tensile strength and tensile strength of specimens of resin composite, with or without chitosan G incorporated, were measured. Using a SEM (S-4700, Hitach, Japan), pictures of microbes were taken and adherent capability of microbes to the surface of resin composite was investigated. The results were as follows; 1. The values of compressive strength, diametral tensile strength and tensile strength, composite resin containing 7㎎/㎖ chitosan G were higher than the control group(p>0.05) but composite resin containing 40 ㎎/㎖ chitosan G were either the same or lower than the control group(P<0.05) 2. The MIC of newly prepared chitosan G for S mutans KCTC 3065 and C albicans KCTC 7965 were more than 2 ㎎/㎖. 3. The adherent capability of microbes significantly decreased as the amount of chitosan G increased in the test specimens compared to the control group for C aibicans KCTC 7965 (P<0.05) but there was no statistical significance for S mutans KCTC 3065(p>0.05) . 4. The cytotoxicity of newly prepared chitosan G for human gingival fibroblast was not showed. In conclusion, resin composite with chitosan G incorporated did not show any statistically significant difference for mechanical properties (p>0.05) but it showed a significant antimicrobial effect against C albicans (P<0.05).

가시오갈피 접합자배로부터 체세포배 발생 과정의 구조적 특성

최용의,소웅영 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

가시오갈피 접합자배를 1.0 mg/L 2,4-D가 첨가된 MS 배지에 배양하였을 때, 배양재료 표면에서 직접 체세포배가 발생되었다. 접합자배를 온전한 상태로 배양하였을 때에 비하여 상처를 주어 배양하였을 때 배발생률이 증가되었으며, 부위별로 절단하여 배양하였을 경우 하배축에서 발생률이 높았다. 체세포배발생에 대한 조직학적 관찰 결과, 유근부위가 잘록한 단일배와 여러개의 배가 서로 융합된 다배가 관찰되었다. 이들 두가지 모양의 체세포배는 접합자배의 부위마다 발생빈도가 달랐는데, 자엽이나 하백축하부에서는 단일배가 주로 관찰되었고, 배형성능이 높은 부위인 자엽절이나 하배축상부에서는 다배의 발생률이 높았다. 단일배는 표피의 단세포 기원되었으나 다배는 모두 표피 및 하표피의 다수세포에서 기원되었음이 조직학적 관찰로 확인되었다. When the zygotic embryos of Acanthopanax senticosus were cultured on MS medium containing 1.0 mg/L 2,4-D, somatic embryos were produced directly from the surface without forming an intervening callus. The frequency of embryo formation was higher in the wounded zygotic embryos than in the intact ones. Hypocotyl explants showed a higher frequency of somatic embryo formation that cotyledon or radicle explants. Two typeds of somatic embryos were observed : one was single embryos with closed radicle which were mainly formed on cotyledon or radicle part; and the other was polyembryos of which hypocotyls were fused one another showing multicotyledons with a single hypocotyl. Histological observation revealed that single embryos originated from the single epidermal cells while polyembryos were derived from massive cells of epidermis of subepidermis.

한국인 임신부에 있어서 영양소의 역가측정

최기영,김웅철,박기현,배도환 중앙대학교 의과대학 의과학연구소 1982 中央醫大誌 Vol.7 No.2

Animal and human studies indicated that inadequate diet for a prolonged period during pregnancy could injure mother, child, or both. In order to prevent this problem, maternal nutyitional status during pregnancy is very important and the evaluation of nutrition during pregnancy have been preceded by many authors in another countries. In Korea, nutrient intake studies of the pregnant women and nutrition surveys in adult by biochemical method have been performed, but there are no data nutrition surveys of Korean pregnant women have been made by biochemical method. In this regard, an exact biochemical titer of the nutrients and the degree of nutrient deficits in Korean pregnant women are needed. In this study, the mean titer of some nutrients and the degree of nutrient deficits by biochemical method in Korean pregnant women were assessed. The objected materials were consisted of 30 cases which had visited the departmant of Obstetrics & Gynecology, Chung Ang University Hospital for antenatal care(32wk-40wk) from March, 1981 to June, 1981. The cases with twin pregnancy, and the cases complicated with materal chronic wasting disease, diabetes, hydroamniosis, hypertensive disorder in pregnancy were excluded in this study. The results were as follows: 1. Mean titer of 6 hours urine execretion of thiamine, riboflavin and N'-methylniacinamide in Korean pregnant women was 44㎍, 466㎍, and 2.33㎎. 2. Mean titer of serum vitamin A, carotene, vitamin C, total protein, calcium, phosphorus, iron and total lipid was 48.1㎍, 154.7㎍, 0.8㎎, 7.0g, 9.8㎎ 3.5㎎, 93㎍, and 578㎎. 3. Percentage of nutrient deficits in Korean pregnant women based on the mean titer of Korean adults was as follow; thiamine-20%, N'-methylniacinamide-7%, total protein-5%, calcuim13%, iron-19%. 4. No cases were deficient in riboflavin, carotene, phosphorus, total lipid and the mean titer of riboflavin and carotene in Korean pregnant women were high compared with thw mean titer of Korean adults.

접착강화제가 치아경조직과의 접척강도 변화에 미치는 영향에 관한 연구

최웅대,박상진 大韓齒科保存學會 1995 Restorative Dentistry & Endodontics Vol.20 No.1

AbstractThe purpose of this study was to investigate the effect of dentin bonding agents on the bond strength of composite resin restorations in case of applying the dentin bonding agents to acid etched enamel surfaces. Freshly extracted 364 bovine anterior teeth were selected as a adherents. 320 enamel specimens were divided into two groups(unetched group (D and etched group ?for testing the shear bond strength, 40 specimens were used for the hardness testing, and 4 specimens of rest were to observe the resin-tag forma- tion into etched enamel surfaces.All surfaces of enamel specimens were polished with 320~1500 SiC paper under conti- nuous running water. In Group (D, 100 enamel specimens were polished and unetched. 220 polished enamel specimens in Group ?were etched with 37% phosphoric acid solution for 60 seconds, washed with water for 20 seconds, and dried with a light air pressure for 60 seconds.Three kinds of dentin bonding agents( Gluma, Prisma, Scotchbond 2) were evaluated the effect on the bond strength to conditioned enamel surfaces. Shear bond strengths were measured on the three cases such as a coating of primer only, a coating of sealer only, and a sequential coating of primer and sealer to acid etched enamel surfaces were compared with the bond strengths measured by the coating of enamel bonding agent followed by the bonding of composite resin (Photo clearfil bright, Kuraray, Japan) to unetched and acid etched enamel surfaces.In addition, the hardness tested on the adhesive fractured surface between composite resin enamel as a mean of evaluation of a factor whether the mechanical bond strengths were affected and the penetration of dentin bonding agents into etched enamel surfaces was also observed. Bond strengths were measured using the method of shear bond strength by a universal testing machine (Instron-4467, USA), statistical test were applied to the results using a one way analysis variance (ANOVA), and hardness was measured by the Vicker's Hardness Tester(MHT-i, Matsuzawa, Japan) and the penetration of the resins were observed by the SEM (Hitachi, S-2300, Japan).The following conclusions were drawn ; 1. Enamel bonding agent showed to affect the improvement of bond strength of composite resin to enamel surface both unetched and etched. 2. Dentin bonding agents could be resulted in increase of bond strength to unetched enamel surface, but there were no statistical significances. 3. Bond strengths to etched enamel surface were significantly decreased with a coating of dentin primer only. 4. Coating of sealer only and coating of primer and sealer noticed the similar bond strengths of composite resin to etched enamel using the enamel bonding agents. 5. The applying method proved to be more effective than the kinds of dentin bonding agents on the bond strength of composite resin to etched enamel than the kind of dentin. 6. Vicker's hardness numbers of dentin bonding agents were lower than that of composite resin, but the degree of penetration of dentin bonding agents into etched enamel surfaces was excellent.