• 수면정신생리
• /
• 제2권2호
• /
• pp.146-155
• /
• 1995

Jet lag can be defined as the cumulative physiological and psychological effects of rapid air travel across multiple time zone. The consequences of jet lag include fatigue, general malaise, sleep disturbances, and reductions of cognitive and psychomotor performance, all of which have been documented in experimental biological and air crew personnel studies. Thus authors tried to study the jet lag of natural travellers by modified self reporting sleep log. Total 61 healthy travellers was studied for 3 days before and 7 days after jet-flights across seven to ten time zone. The eastbound travelling group was 38 persons, aged 19 -70 and westbound travelling group was 23 persons, aged 13 - 69. Sleep onset time, wake-up time, sleep latency, awakening frequency on night sleep, awakening duration on night sleep, sleepiness at wake-up and nap length were evaluated. Our results suggested that the 7 to 10 time zone shift gave significant influence to traveller's sleep-wake cycles. The date which subjective physical condition was recovered on was $5.16{\pm}1.50$ day after arrivals for eastbound, while for westbound, $4.91{\pm}1.62$ day. In eastbound travelling, sleep onset time became later than baselines and could not recover until 7th day. But in westbound, it became earlier than baseline and could recover until 6th day. The mean score of 24-hour sleepiness was greater in eastboumd than westbound. Therefore the eastbound travelling caused more sleep-wake cycle disturbance and daytime dysfunction than westbound travelling. In other parameters, there was no definite difference between east and westbound. From our results, it was suggested that the symptom severity of jet lag was dependent on the travelling direction. To demonstrate more definite evidence, large sized data collections and comparision by age difference were needed.

• 한국전자파학회논문지
• /
• 제14권8호
• /
• pp.855-862
• /
• 2003

본 논문에서 제안하는 안테나는 기존 내장형 안테나의 일종인 PIFA의 단점으로 협대역 문제를 해결하기 위하여, 복사 소자와 접지면 사이에 단락판을 위치시키는 변형된 안테나 형태인 PIFA(Planar Inverted-FAntenna) 구조를 제안하였다. 또한 보다 넓은 대역폭을 가지도록 방사 패치에 톱니모양의 perturbation을 주었다. 제안된 방식으로 단말기에 내장형으로 사용하기 위하여 안테나의 높이(h=0.015λ)를 최소한으로 하여 원하는 대역폭(5.2 %)을 얻었다. slim형으로 하기 위해 안테나의 특성을 급전위치(Yf, Zf), 단락 스트립(Short plate)의 위치 (Zs), 폭 (Ws), perturbation폭(w), 길이(d), 단락 스트립 높이(h), 유전율 변화($\varepsilon$$_{r}$)가 안테나에 어떤 변화를 미치는지를 조사하였다. 또한 기존 PIFA 안테나와의 대역을 비교하고, 제안된 패턴을 H, E plane으로 나타내었다. 논문의 객관성을 입증하기 위하여 FIM(Finite Integration Method) 방식에 기반인 MWS(Microwave Studio) 소프트웨어를 이용하여 Simulation 하였으며, 각각의 구조 파라미터 변화에 따른 안테나 특성을 분석하였다. 그리고 실제 제작한 안테나의 실험결과와 비교하여 증명한 결과, 제안된 방식의 PIFA 안테나 실용화가 가능성을 확인하였다..

• 한국전자파학회논문지
• /
• 제14권12호
• /
• pp.1269-1275
• /
• 2003

본 논문에서는 구조적으로 비 방사 유전체 로트만 렌즈에 적절한 갭 결합된 단향성 유전체 방사체를 안테나단으로 갖는 비방사 유전체 로트만 렌즈를 설계하였다. 비방사 유전체 로트만 렌즈는 어레이 팩터의 부엽의 최소화를 위해서 최적화 설계되었고 단향성 유전체 방사체의 공진기와 갭의 길이와 같은 설계 파라미터는 차단 영역 도파관의 등가회로 모델을 이용하여 계산하였다. 동작 주파수는 38 GHz이고 시뮬레이션 되어진 단향성 유전체 방사체의 결과(산란 행렬, 방사 패턴)는 측정되어진 결과와 일치함을 보였다. 단향성 유전체 방사체 안테나단을 포함한 다중빔 피드인 로트만 렌즈의 방사 패턴은 측정되어진 갭 결합된 단향성 유전체 방사체의 방사 패턴에 로트만 렌즈의 최적화된 어레이 팩터를 곱해서 구하였다. 구해진 전체 방사 패턴에서 -60 dB 이상 부엽이 억제되어짐을 알 수 있었다.

• Archives of Pharmacal Research
• /
• 제29권1호
• /
• pp.88-95
• /
• 2006

Analysis of molecular nature of mitochondrial DNA (mtDNA) could be powerful marker for anthropological studies of modern populations. While population genetic studies on mtDNA have been reported for several ethnic groups, no such study has been documented for the Korean population. We surveyed mtDNA polymorphisms in the HVS I of noncoding D-loop region and its upstream region from 430 unrelated healthy Korean population by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing analysis. PCR product with 2,790 bp spanning the specific mtDNA region (mt13715-16504) was subjected to RFLP analysis using 6 restriction enzyme (Hinf I, Hae III, Alu I, Dde I, Mbo I, Rsa I). On the PAUP analysis of PCR-RFLP results, 38 mtDNA haplotypes (Hap 1-38) were detected in the Korean populations, which were classified into 11 haplogroups (Grp 1-11) of related haplotypes encompassing all 38 haplotypes. In comparison of sequencing data with Anderson's reference sequence, the transition type was more prevalent than the transversion type. Insertions or deletions were not found. In addition, three of the polymorphic sites (A16240C, A16351G, G16384A) in HVS-I region are determined newly. The polymorphic sites were distributed randomly in the region, though the frequency at each site was variable. Thus, this research might be required for the genealogical study of Orientals.

• 동아시아식생활학회지
• /
• 제25권2호
• /
• pp.234-245
• /
• 2015

This study aimed to investigate factors related to Chinese female marriage immigrants' dietary adaptation. An in-person survey was conducted by a research institute on Chinese female marriage immigrants married to Korean men, having one child or more aged 1~6 years old, and having resided in Korea for at least 1 year before the survey. Data were collected from 309 respondents comprising 151 Han Chinese and 158 Korean-Chinese during the summer of 2013. About two-thirds of respondents were in their 30s and had resided in Korea for 5 to 10 years. Based on the overall mean score for dietary adaptation level (3.50 out of 5 points), the respondents were classified into two groups: low dietary adaptation group (mean score 3.11) and high dietary adaptation group (mean score 3.81). The results of comparative analysis between the two groups showed that the levels of acculturation (p<0.01) and healthy dietary behavior (p<0.01) for the high dietary adaptation group were significantly higher than those of low dietary adaptation group. The number of respondents of the high dietary adaptation group reporting increased food diversity (p<0.01) and decreased frequency of skipping meals (p<0.01) was significantly higher compare to the low dietary adaptation group. Multiple regression analysis was conducted to identify factors related to dietary adaptation. General characteristics, levels of acculturation, and healthy dietary behavior were included as independent variables. As a result, levels of acculturation and healthy dietary behavior as well as education level, monthly household income, and length of residence in Korea were associated with dietary adaptation. In conclusion, Chinese female marriage immigrants showing acculturated and healthy dietary behaviors adapted well to Korean dietary life. The results from this study suggest that diet-related adaptation support programs for Chinese female marriage immigrants may positively affect their acculturation and dietary behaviors.

• 대한간호학회지
• /
• 제21권3호
• /
• pp.383-395
• /
• 1991

This study was to investigated the factors influencing the decisions of nurses to resign. The purpose was to contribute information useful for the effective management of nurse staffing resources. The specific objectives were as follows : 1. To investigate the level of job satisfaction of nurses who resign. 2. To analyze the relationship of job expectations and the decisions to resign. 3. To investigate the major reason for nurses' resignations. 4. To identify the relationship of the general characteristics of the nurses and the factors influencing their decisions to resign. 5. To analyze the relationship of the intention to resign and the factors influencing the decisions to resign. The sample consisted of 90 nurses who worked at Y hospital in Seoul from march. 1987 to Feb. 1988 and who had resigned. The instruments used for this study were slavitt et al's Index of Work Satisfaction Scale and a job expectations scale developed by the researcher Analysis of data was done using frequency, t-test and ANOVA. The results of study were as follows : 1. There was no difference in the job satisfaction level of nurses who resigned compared with nurses in active service but the subcategory interaction score was lower and the subcategory salary score was higher than for nurses in active service. 2. Low job expectation scores influenced the decision to resign. 3. The major reason for resigning were personal problems such as marriage, childbirth, and relocation of family. 4. The length of employment and the number of different service areas of the nurses who resigned were associated with the job satisfaction level. 5. The nurses who had have an intention to resign while in active service had lower scores for job satisfaction and the job expectation score was a greater influence on the decision to resign. In conclusion, the factors influencing the decisions of nurse to resign were job satisfaction, job expectations and intention to resign while still in active service.

• 전산구조공학
• /
• 제10권2호
• /
• pp.233-242
• /
• 1997

이 논문은 연속보의 동적 최적설계에 관한 연구이다. 본 연구에서는 연속보의 근사적인 최적제원을 결정하기 위하여 컴퓨터 프로그램의 실행결과를 이용한 기법을 이용하였다. 경간길이, 질량 및 휨강성이 변화하는 연속보의 자유진동해석과 이동 집중하중이 작용하는 경우 동적응답해석을 실행할 수 있는 컴퓨터 프로그램을 개발하였다. 모형실험 결과와 이론적인 해석결과가 잘 일치하여 해석결과의 타당성을 검증할 수 있었다. 설계효율을 나타내기 위하여 최대 동적응력, 경간사이의 응력차이, 이동 집중하중이 작용하는 점에서의 rms 처짐 및 전체지간의 총질량 등 4가지의 무차원 변수들의 선형결합으로 이루어지는 최적함수를 정의하였다. 3경간 연속보에 대한 해석결과 개략적인 최적제원을 갖는 연속보로 설계하는 경우 등간격의 등단면 연속보에 비해 설계효율을 개선할 수 있음을 알 수 있었다.

• 복식문화연구
• /
• 제11권6호
• /
• pp.889-901
• /
• 2003

The purpose of this study is to look into the physical features for each residential area by the age, with the female subjects residing in Beijing and Shanghai. This would provide the specific information regarding the body types of Chinese adult women, and additionally it would assist the effective advancement into the Chinese local markets by serving as the basic data for the size development and fitting improvement of clothing products for Chinese women. The body measurements were made with 525 adult female subjects of 20 to 49 years of age, residing in Beijing and Shanghai, China. The number of measurements items was 79. The results are as follows: As they grew older, the women residing in Beijing and Shanghai all showed increases in the items of width, thickness, girth, and length, which are highly correlated with the physical obesity, while they did not show any differences by the age range in the item of height. Differences were also found in the tendency of the type distribution by the age range of Chinese adult women in each residential area. As they grew older, the women residing on Beijing showed increases in the distribution of Body type 2 and Body type 4, which clearly indicated the features of obesity. On the other hand, the women residing in Shanghai showed the almost similar distribution in their 20's and 30's, while those in their 40's showed a high frequency in Body type 2 than in Body type 4.

• 한국통신학회논문지
• /
• 제28권8A호
• /
• pp.626-632
• /
• 2003

본 논문에서는 모드정합법을 이용하여 도체두께를 고려한 비대칭 결합선로의 특성을 해석하고, 중심주파수 5㎓ 인 정방향 -3㏈ 방향성 결합기를 설계 및 제작하였다. 결합선로의 결합도에 대한 연구는 대부분 기하학적인 구조의 변화에 대해 연구되어 왔으나, 본 논문에서는 도체두께가 비대칭 결합선로의 간격, 선로 폭, 결합기의 길이에 미치는 영향을 이론적으로 분석하고, 도체두께를 고려한 비대칭 결합선로를 이용한 결합기를 설계하여 도체 두께가 두꺼울수록 강한 결합으로 인하여 정방향 결합기의 결합길이가 짧아지고 광대역 특성이 얻어지는 결과를 얻었다. 본 논문에서는 5㎓ 중심주파수로 한 도체두께가 서로 다른 비대칭 결합선로로 구성된 정방향 -3㏈ 결합기를 설계하고, 제작 및 실험을 통하여 약 -4.05㏈∼-4.09㏈의 결합특성을 갖는 주파수특성 측정결과를 얻어 설계 값에 거의 근접하는 것을 확인하였으며, 도체 두께를 고려한 정확한 설계로써 결합선로에서 강한결합과 광대역 특성을 만들 수 있다는 사실을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권6호
• /
• pp.330-336
• /
• 2004

In this work, in order to obtain the detailed information about lightning electromagnetic pulses, the electric fields radiated from multiple lightning return strokes were measured and analyzed statistically. The electric field measuring system consists of a hemisphere antenna of 30cm in diameter, integrator and data acquisition device, and its frequency bandwidth ranges from 200Hz to 1.56MHz, and the sensitivity is 0.96㎷/V/m. The electric field signals are digitized every 200ns with the transient signal analyzer having the resolution of 12-bit and the recording length of 5 kilowords and are registered at personal computer. As a result, the electric fields produced by the first return stroke begin with a slow initial part or front, which starts just after or during the last stepped leader. On the average the rise times of the electric fields for the positive first, second and third strokes are 4.21${\mu}\textrm{s}$, 3.94${\mu}\textrm{s}$ and 2.75${\mu}\textrm{s}$, respectively, and those for the negative first, second and third strokes are 3.46${\mu}\textrm{s}$, 3.15${\mu}\textrm{s}$ and 2.79${\mu}\textrm{s}$, respectively. The zero-crossing times of the electric fields for first return strokes range from about 10 to 80${\mu}\textrm{s}$. The mean zero-crossing times for subsequent return strokes are shorter than those for first lightning return strokes.