관광변수의 계절변동 분석 : 국립공원탐방객을 중심으로

원융희,이돈재 龍仁大學校 1997 용인대학교 논문집 Vol.14 No.-

The purpose of this study is to analyze seasonalities with regard to 18 National Parks. To effectively analyze the seasonalities, national parks were divided into six groups: Jungbu, Chungcheng, Seonam, Dongnam, Mts and Shores. Analysis of Variance tables, Arima Model and Log Difference were used to analyze the seasonalities of national park. The paper is intended to examine the difference between mean and variance of visitors and investigate the stages which are converging or enlarging between inter-season and intra-season in each cases. To verifiy the study, we converted original data into seasonal dummy variables and deseasonally adjusted data to eliminate the secular trend, cyclical variation and irregular variation. This analysis results in several categories. The stationary stage was not shown in most of the national parks. As to the seasonality between inter-season and intra-season, it was difficult to fond the stylized facts uniformed characters converging or enlarging trends. The fluctuation of variation was also not found in the parks near metroplitans. It means that the parks without accessibility and demand threshhold show high variance of visitors between seasons. The least interval variation in the log difference was found in Jungbu Group including Seolak, Gaeyong, and Bukhan. But the most interval variation due to the high demand in summer was revealed in the Shores Group including Dadohae, Taean, and Hanryo. Each Mts. group has its own distinctive features. For example, in case of Naejang, the most variation was shown due to the highest demand in fall. Finally, the seasonal variance of visitors are still considerably exist across the national parks, but this difference is closer to the mean as time goes.

인버터 구동용 유도전동기 고정자 권선의 절연특성 연구

황돈하,김동희,이광식,정원영,김영훈,오승훈 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

Inverters with high speed switching and advanced PWM techniques are widely used for variable speed applications. But some adverse effects on the stator winding insulation are reported due to excessive voltage stress, which results in the premature insulation breakdown. This is aggravated by the high switching speed of modem switching devices such as IGBT (Insulated Gate Bi-polar Transistor) with which the rate of rise in voltage (dv/dt) increases considerably. In this paper, the test results for evaluation on the stator winding insulation of 310V induction motors are presented. Also, the insulation characteristics are presented in order to analyze the insulation strength under high voltage due to high switching speed of IGBT PWM inverter. 26 induction motors of 6 types with different wires and insulation techniques are built and thoroughly tested. The maximum partial discharge (PD) magnitude (Qm) and the discharge inception voltage (DIV) are obtained by PD test. Under AC current test, the rate of change in AC current (ΔI) and the change in dissipation factor (Δtanδ) are measured. From the above test data, the effects due to different wires and insulation techniques on the insulation characteristics of low-voltage induction motors are compared and analyzed. The insulation technique to enhance the insulation strength is suggested from the test results.

신경조직망의 배경 및 응용

이원돈 충남대학교 자연과학연구소 1988 忠南科學硏究誌 Vol.15 No.2

Various models in neural networks are introduced in this paper, with their advantages including parallelism, completion, fault tolerance, cooperative information processing, and optimization.

저금리시대의 생명보험산업

이원돈 한국보험학회 2003 保險學會誌 Vol.65 No.-

1997년 말 금융위기 직후 폭등하였던 시장금리는 하향안정세를 거쳐 현재의 저금리 상황으로 이어졌다. 선진 외국의 예처럼 저금리 상황은 계속 지속될 것이며 반등의 경우에도 과거의 두 자리 수 금리시대는 없을 것이라는 것이 중론이다. 약속한 이율(예정이율)을 기준으로 보험료를 받아 장기적으로 운용해야 하는 생명보험회사로서는 시장금리의 변동이 경영에 미치는 영향이 지대하다고 볼 수 있다. 특히 고금리보다는 저금리 상황의 지속이 생명보험회사의 경영에 치명적이다. 본고에서는 현재의 저금리 상황에서 지속적인 이자율차손을 보고 있는 우리나라 생명보험회사의 현황과 그 원인을 분석하고, 같은 상황을 겪은 미국과 현재 겪고 있는 일본의 생명보험업계가 어떻게 대응하였고 어떻게 대응하고 있는가를 살펴보고, 우리의 대응방안을 생명보험업계 차원과 제도적인 차원에서 제시하고자 한다. Low market interest rates have been stabilized since the rates sharply rose right after the 1997 Financial Crisis. The trend of low market interest rates is expected to continue like the cases of developed countries. Volatility of market interest rates heavily affects the profitability of life insurers who have long term liabilities with fixed(assumed) interest rates during the period of insurance. Especially, a low interest rate trend become more critical to life insurers than a high trend. This study analyses the current status of Korean life insurers who have experienced heavy losses from negative spreads under the recent trend of low market interest rates, examines the same cases of U.S.A. and Japan, and finally proposes possible ways to cope with the situation from the standpoints of life insurers and supervising authority.

고속전철 추진 시스템의 미끄럼 방지 제어기법에 관한 연구

황돈하,김동희,노채균,심광열,조규판,정원영 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

Induction motor drive with PWM inverter control has been developed for Korean High Speed Railways. To improve traction performance, the anti-slip control(ASC) to recover adhesion must be considered. This paper describes a novel hybrid anti-slip control method for the induction motor drive. By introducing the vector control for drive system, quick response of the motor torque can be achieved when wheels are going to slip. A hybrid control scheme by mixing two conventional control methods (slip velocity feedback control and slip detection pattern control) for wheel slip and re-adhesion is proposed. This control method is simulated by motor drive, train load, and friction-creep models. The train running simulation results based on induction motor vector control with PWM inverter show that good re-adhesion characteristics are obtained.

Application and Inspection Potential of Ultrasonic Guided Waves in NDT

송원준,Rose, Joseph L.,정희돈,임종수 한국비파괴검사학회 2003 최신 비파괴검사기술의 국내연구 동향에 관한 워크샵 Vol.2003 No.1

유도초음파를 이용한 비파괴 검사 및 평가기법은 산업설비의 안전성 진단, 제품의 품질검사 그리고 의료분야 등 여러 분야에서 널리 적용되고 있다. 본 논문에서는 유도초음파에 대한 간략한 개요와 파이프 내에서의 유도초음파 발생 및 Focusing, Hybrid BEM을 이용한 wave scattering 해석, 그리고 유도초음파 검사기법의 적용 사례를 기술하였다.

저금리와 생명보험산업

이원돈 대구대학교 경제경영연구소 2003 경제경영연구 Vol.1 No.3

1997년 말 IMF 외환위기 직후 폭등하였던 시장금리는 하향안정세를 거쳐 현재의 저금리 상황으로 이어졌다. 선진 외국의 예처럼 저금리 상황은 계속 지속될 것이며 반등의 경우에도 과거의 두 자리 수 금리시대는 없을 것이라는 것이 중론이다. 약속한 이율(예정이율)을 기준으로 보험료를 받아 장기적으로 운용해야 하는 생명보험회사로서는 시장금리의 변동이 경영에 미치는 영향이 지대하다고 볼 수 있다. 특히 고금리보다는 저금리 상황의 지속이 생명보험회사의 경영에 치명적이다. 본고에서는 현재의 저금리 상황에서 지속적인 이차손을 보고 있는 우리나라 생명보험회사의 현황과 그 원인을 분석하고, 같은 상황을 겪은 미국과 현재 겪고 있는 일본의 생명보험업계가 어떻게 대응하였고 어떻게 대응하고 있는가를 살펴보고, 우리의 대응방안을 생명보험업계 차원과 제도적인 차원에서 제시하고자 한다.

유기용제 취급근로자들의 요중대사물질과 말초임파구 자매염색분체교환 발현빈도에 관한 조사연구

김돈균,황인경,류철인,이수일,정갑열,이용환,이충렬,현원일,김석봉,전용덕 大韓産業醫學會 1990 대한직업환경의학회지 Vol.2 No.1

저자들은 유기용제 취급여성근로자 90명을 대상으로 1988년 7월부터 1989년 8월까지 말초혈액임파구에서의 자매염색분체교환의 발현빈도를 조사하고 이들의 업종, 근속연수, 요중마뇨산 농도등이 자매염색분체교환의 발현빈도에 미치는 영향을 조사하였으며 그 결과를 요약하면 다음과 같다. 1. 유기용제 취급근로자들의 말초혈액임파구에서의 자매염색분체교환의 발현빈도는 대조군에 비하여 유의하게 증가되었다. 2. 말초혈액임파구에서의 자매염색분체교환의 발현빈도가 가장 높은 업종은 프라스틱제품 제조업이었다. 3. 근속연수가 말초혈액임파구에서의 자매염색분체교환의 발현빈도에 미치는 영향은 현저하지 않았다. 4. 요중마뇨산농도와 말초혈액임파구에서의 자매염색분체교환의 발현빈도간에는 유의한 상관관계가 있었다. In order to know the possibility of utilizing the sister chromatid exchanges as an index which could evaluate the effect of organic solvents on the health in industrial workers, the authors studied the effects of the inductivity of sister chromatid exchanges in peripheral lymphocytes from 90 female workers expoxed to organic solvents and 20 non-exposed female workers. The results obtained were as follows : 1. The frequency of sister chromatid exchanges in peripheral lymphocytes from 90 female workers exposed to organic solvents was significantly increased in comparison with 20 control subject. 2. The frequency of sister chromatid exchanges was significantly increased in the workers who were employed in the manufacture of plastic materials than the other manufactures. 3. There were no significant differences in the frequency of sister chromatid exchanges by carriers of the exposed workers.

농업부문 웹캐스팅의 이용 실태와 활성화 방안

최돈우,김두한,박원흠 한국식품유통학회 2004 食品流通硏究 Vol.21 No.2

Webcasting is a new trend of fusion media, which multimedia, musics and images are captured and stored in real time and broadcasted through internet. This study was attempted to observe the current status of webcasting in agriculture which are used by the farmer of fruit products, and identified the problems and issues which are currently confronted with the webcasting in agriculture and sought some feasible strategies for improving and activating the webcasting. In the near future. it is very important that decision-making of the farmers on production and marketing through webcasting information are to increase its market competitiveness under the current situation which is ever-changing domestic and international production and marketing environments. In order to activate the webcasting in agriculture, it is necessary to supply personal computers across farm level, to strengthen educational training programs of computer on farmers, and to found public webcasting center which is collected, developed and provided diversified and specialized contents of webcasting.

家蠶育種을 위한 繭形質의 遺傳分析

鄭元福,朴東洵,姜弼敦 東亞大學校 1986 東亞論叢 Vol.23 No.1

蠶作安定多收性 育成의 重要性에 비추어 有用한 形質의 遺傳關係를 初期에 推定하고 效率的인 選拔을 爲한 基礎資料를 얻고자 形質相互間의 特性을 고려한 2個品種을 二面交雜하여 F??의 主要 形質에 대한 優性程度 및 組合能力 등을 檢定한 結果는 다음과 같다. 1. Vr-Wr graph에서 雌單繭重과 雄單繭重은 超優性으로, 雌繭層重, 雄繭層重, 雌繭層比率 및 雄繭層比率은 各各 不完全優性으로 推定되었다. 2. 各 形質에 대한 分散成分의 推定에서 雌繭層重, 雄繭層重, 雌繭層比率 및 雄繭層比率은 遺傳子의 相加的 效果가 優性效果보다 더 컸고, 雌單繭重과 雄單繭重은 反對의 樣相이었다. 優性程度와 平均優性程度에서도 雌雄單繭重에서 超優性이고, 雌雄繭層重과 繭層比率은 各各 不完全優性이었다. 3. 一般組合能力과 特定組合能力을 檢定한 바, 6個形質 모두 一般組合能力(GCA)이 特定組合能力(SCA)보다 높게 評價되었다. 4. GCA 效果의 경우, 蠶114가 雌單繭重이 6個形質中에서 가장 높았고, 蠶108이 雄單繭重, 雌繭層重, 雄繭層重, 雌繭層比率 및 雄繭層比率에서 各各 높게 評價되었다. SCA 效果는 蠶107×蠶113은 雌繭層比率에서, 蠶107×蠶114는 雄繭層重과 雄繭層比率에서, 蠶108×複形蠶은 雌繭層重에서, 蠶108×中14는 雄單繭重에서, 蠶113×綠東亞는 雌單繭重에서, 蠶114×複形蠶은 雌單繭重, 雄單繭重 및 雄繭層重에서, 中14×綠東亞는 雌繭層重, 雌繭層比率 및 雄繭層比率에서 各各 높게 評價되어 주로 奬勵蠶品種인 蠶108, 蠶114가 關與하는 組合에서 SCA 效果가 큰 傾向이었다. Since the estimates of the genetic relations between characters gave us effective basic informations about the selection of good strains of the silkworm, this experiment was carried out to estimate the degree of dominance and the combining ability for the some main characters of the silkworm such as cocoon weight and cocoon layer ratio and weight, using the 21 combinations of F??'s by diallel corsses of seven strains of the silkworm. As the result of this experiments, some conclusions obtained were as follows. 1. The male and female cocoon weights are inferred over dominance and their cocoon layer weights and ratio partial dominance from Vr-Wr graph. 2. The additive effect of gene on the male and female cocoon layer weights and ratio is higher than the dominance effect, on the contrary, the latter on both the cocoon weights is higher than the former. Also, in the average degree of dominance, both the cocoon weights are over dominance and the male and female cocoon layer ratio and weights are partial dominance. 3. The effect of general combing ability(GCA) on the 6 characters analysed in this experiments is higher than that of specific combining ability(SCA). 4. In the effect of GCA, the male cocoon weight of Jam 114 is the highest of 6 characters, the male and female cocoon layer ratio and weights of Jam 108 and the male cocoon weight of Jam 108 are relatively high. The effect of SCA on the female cocoon layer ratio of Jam 107×Jam 113, the female cocoon layer weight of Jam 108×Bokhyeong Jam, the male cocoon weight of Jam 108×Jung 14, the female cocoon weight of Jam 113×Nog Dong-A, the male and female cocoon weights and male cocoon layer weight of Jam 114×Bokhyeong Jam, and the female cocoon layer weight and the male and female cocoon layer ratio fo Jung 14×Nog Dong-A is estimated high. Generally, the combinations including the recommended strains of the siklworm such as Jam 108 and Jam 114 tend to be high in the effect of SCA.