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

서울시 사회복지시설 근무 사회복지사들의 직무스트레스 수준

최수찬,김상아,이정은,박웅섭 大韓産業醫學會 2007 대한직업환경의학회지 Vol.19 No.4

목적: 사회복지사의 직무스트레스 실태를 알아보고,복지시설 유형과 직업조건에 따른 직무스트레스의 차이를 조사하고자 하였다. 방법: 서울시 소재 681개 사회복지시설에 근무 중인 사회복지사를 대상으로 우편설문을 시행하였으며 ,최종 분석 사용된 설문지는 총 432부였다. 한국인 직무스트레스 측정도구(KOSS)의 단축형을 사용하여 직무스트레스를 측정하였고,빈도분석,t-test,ANOVA 분석을 실시하였다. 결과: 노인복지시설의 경우 타 기관에 비해 직무요구,직무자율성결여,보상부적절로 인한 스트레스 수준이 모두 높게 나타났다. 작업조건별로는 업무형태,근무시간, 정규휴식시간,직위에 따라 직무스트레스 수준에 차이가 있었다. 서비스와 행정을 둘 다 수행하는 경우에 직무스트레스총점,직무요구,관계갈등,직무불안정,조직체계,보상부적절, 직장문화 영역의 직무스트레스 수준이 높았고,근무시간이 10시간 이상인 경우에 직무요구 영역에서 ,일선 및 선엄사회복지사가 직무자율성결여 및 보상부 적절로 인한 직무스트레스 수준이 높게 나타났다,또한 정규휴식시간 유무에 따라서는 직무스트레스 총점 및 직무스트레스의 7개 하위 영역 모두에서 유의한 차이가 있었다. 결론: 사회복지사의 직무스트레스를 적절한 관리하기 위해서는 서비스와 행정업무 병행에 대한 조치 및 정규휴식시간 확보가 필요하고,특히 노인복지시설 사회복지사의 직무스트레스에 대한 적절한 관리가 필요하다. Objectives: To investigate the level and variation of job stress according to social welfare organizations and work conditions among social workers in Seoul. Methods: For this survey, a self-reported questionnaire was administrated to 1,000 social workers working in organizations for social welfare practice in Seoul. A total of 432 completed questionnaires were received (43.2% response rate). Results: Social workers working in welfare organizations for the aged had higher job stress in the areas of job demand, insufficient job control and lack of reward than those in other welfare organizations. In addition, higher job stress was found in those in charge of both service and administrational work, without regular time for rest, working over 10 hours, in the frontline and senior grade. Conclusions: This study confirms the importance of guaranteeing regular time for breaks in the work schedule and of considering the service and administrational work ratio in job arrangement in order to alleviate stress of social workers.

京畿道의 植物相 : 태화산, 화야산, 대부도, 칠현산, 철마산, 검단산

崔道烈,張珍成,金正猷,全正壹,金輝,閔雄基,姜佑昌 서울대학교 수목원 2001 서울大學校 樹木園 硏究報告 Vol.- No.21

This study was conducted in order to explore general flora of the Gyounggi-do Province and to clarify the distribution of some specificated taxa of the Korea. Daebu-do Island, Mt. Taewha, Mt. Hwaya, Mt. Gumdan, Mt. Chilhyun and Mt. Chulma among eighth grade-area of the Degree of Green Naturality (DGN) within the boundary of the Gyounggi-do Province were visited to investigate local flora. The number of identified vascular plant species were as follow; Mt. Hwaya: 120 species (99 genera of 67 families), Mt. Teawha: 132 species (103 genera of 56 families), Daebu-do Island: 124 species (103 genera of 50 families), Mt. Chulma: 129 species (99 genera of 67 families), Mt. Gumdan: 121 species (96 genera of 52 families), Mt. Chilyun: 90 species (74 genera of 42 families). The endemic Clematis brachyura Maxim. was found to distribute Daeby-do. It seemed that plantation was occupying large area in forest of the Gyounggi-do Province. Forty two specificated taxa were identified and 3 taxa, 10 taxa, 5 taxa, and 24 taxa were sorted into forth grade, third grade, second grade, and first grade respectively. Mt. Taewha showed the highest record (16 taxa) in the number of specificated taxa, Mt. Hwaya was the next with 13 taxa. Mt, Chulma (12 taxa), Mt. Gumdan (11 taxa), Daebu-do Island (7 taxi), and Mt, Chylma (4 taxi) followed. Mt. Taewa and Mt. Whaya were found to be relatively higher in the score calculated front the specificated taxa distribution, while Daebu-do Island and Mt. Chilyun were lower, that difference was probably due in part to consequences of severe disturbance of human activities. With respect to the consequences of severe disturbance of human activities. With respect to the geographical proximity to the Gangwon Province, Mt. Hwaya showed higher similarity of the species composition to that of the Mt. Jumbong.

陶淵明 田園時의 形成背景 : 陶淵明의 田園時 硏究(Ⅲ)

崔雄赫 대구효성가톨릭대학교 외국어문학연구소 1990 語文學硏究 Vol.3 No.-

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

합기도 참여와 스포츠 태도의 관계

최웅재 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

This paper studied the relationship between The Relationship Between Participated in Hapgido And Sport Attitudes of Children. To attain the goal of the study described above paragraphs, Children's Hapgido participants in Daejeon 2004. Then, using the stratified random Sampling methods, finally drew out 292 participants. The material collection device was the brochure named <The relationship between The Relationship Between Participated in Hapgido And Sport Attitudes of Children>, To analyze materials, the one-way "ANOVA" was used as statistic analysis techniques. The conclusion based on above study method and the result of material analysis are here blew. First, Children's Hapgido participation frequency is positive Sport Attitudes of Children. Second, Children's Hapgido participation density is positive Sport Attitudes of Children. Third, Children's Hapgido participation interval is positive Sport Attitudes of Children.

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.

참당귀(Angelica fifas Nakai)의 캘러스로부터 체세포배 발생에 미치는 계대배양 주기의 영향

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

Embryogenic callus was produced form leaf segments cultured on medium containing 1.0 mg/L 2,4-D. The callus gave rise to somatic embryos after transfer the embryogenic callus to medium without 2,4-D. Also, somatic embryogenesis occured from aged callus on medium containing 2,4-D. To investigate the effects of culture periods on somatic embryogenesis the embryogenic calli were cultured for 2, 4, 6 and 8 weeks on medium containing 1.0 mg/l 2,4-D and then transferred to medium with or without 2,4-D. In prolonged preincubation, somatic embryos were formed early and at high frequency and their development normally occured. When subcultured on medium containing 2,4-D, the callus preincubated for 6 to 8 weeks was capable of producing somatic embryos. Histological observation revealed that 4 weeks-old embryogenic callus on medium containing 2,4-D was composed of mainly typical embryogenic cells, whereas the 8-weeks-old callus was composed of nonembryogeinc cells and that. In the developing state of somatic embryo on medium without 2,4-D, all the cells of callus were in vacuolated and elongated except developing somatic embryos.

태권도선수의 운동 상해요인과 대처방안에 관한 연구

최춘길,하웅의 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The purpose of this study was to investigate the variables relating to the incidence and copying strategies of taekwondo athletic injury. The subjects were taekwnondo athletic(n=40) from K university. In The method of this study, athletic injury questionnaire was designed for the purpose of this study researcher. The selected variables relating to the incidence of athletic injury of this study were training game process variable, game boundary. The conclusions and implications of this study were as follows : The variables relating to the injure incidence of taekwondo player were lack of skill and strategy(47.5%), training too hard(42.5%), lack of basis physical ability(35%) in training, game process variables, physical fatigue(77.5%), indifference of warm-up, cooling down (62.5%), individual mistake(30%). In boundary variables were exceed tention(32.5%), lack of self-confidence(30%), high anxiety(25%).