• 한국인구학
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• 제29권3호
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• pp.51-72
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• 2006

우리나라의 노동생명표 대부분은 Wolfbein & Wool의 전통적 방법에 의해 작성되고 있다. 그러나 여성의 경제활동참가율이 M자 형태를 보이므로, 이러한 방법은 여성의 노동기대여명 측정에 부적합하다. 한편. 증감 노동생명표는 여성에게도 동일하게 적용될 수 있으나, 개인의 경제활동 상태 전이에 대한 자료가 필요하다. 본 연구는 Garfinkle과 Pollard et al.의 노동생명표가 Hoem, Schoen & Woodrow에 의해 개발되고, 미국 노동통계국이 채택하고 있는 증감 노동생명표와 본질적으로 동일하다는 점을 보여주고 있다. 또한 이들의 노동생명표는 전통적인 방법에 의한 생명표와 마찬가지로 일반적인 증감노동생명표처럼 개인의 경제활동 상태간 전이확률을 추정하지 않고, 공표된 거시적 경제활동참가율을 사용할 수 있는 장점이 있음을 보여주고 있다. 아울러, 통계청이 발표한 2000-2050년의 간이생명표를 바탕으로 성 연령별 경제활동참가율 전망치를 추정하고, Garfinkle-Pollard의 증감 노동생명표 방법론에 의한 노동기대여명을 전망하였다. 그 결과 2000년에서 2050년 동안 65세의 노동기대여명은 남자 5.8년에서 7.7년, 여자 4.1년에서 5.1년으로 증가되었다. 그러나, 65세 이상 고령자의 경우는 자료처리 방법 및 향후 사망확률 가정에 따라 노동기대여명이 다소 차이를 보였다. 정확한 노동기대여명의 측정 및 전망을 위해서는 고령자의 경제활동에 대한 상세한 자료가 필요함은 물론, 향후 사망력 가정에 대한 심층 연구가 수반되어야 할 것이다.

• 한국지반환경공학회 논문집
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• 제20권12호
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• pp.33-39
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• 2019

The upsurge of population, internal migration, economic activities and developmental works has brought significant land use and land cover (LULC) change over the period of 1990 and 2010 in the Bagmati basin of Nepal. Along with alteration on various other ecosystem services like water yield, water quality, soil loss etc. carbon sequestration is also altered. This study thus primary deals with evaluation of LULC change and its impact on the soil carbon storage for the period 1990 to 2010. For the evaluation, InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Carbon model is used. Residential and several other infrastructural development activities were prevalent on the study period and as a result in 2010 major soil carbon reserve like forest area is decreased by 7.17% of its original coverage in 1990. This decrement has brought about a subsequent decrement of 1.39 million tons of carbon in the basin. Conversion from barren land, water bodies and built up areas to higher carbon reserve like forest and agriculture land has slightly increased soil carbon storage but still, net reduction is higher. Thus, the spatial output of the model in the form of maps is expected to help in decision making for future land use planning and for restoration policies.

• Journal of Korean Neurosurgical Society
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• 제65권1호
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• pp.96-106
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• 2022

Objective : The most common complication of anterior cervical discectomy and fusion (ACDF) is cage subsidence and maintenance of disc height affects postoperative clinical outcomes. We considered cage subsidence as an inappropriate indicator for evaluating preservation of disc height. Thus, this study aimed to consider patients with complications such as reduced total disc height compared to that before surgery and evaluate the relevance of several factors before ACDF. Methods : We retrospectively reviewed the medical records of 40 patients who underwent stand-alone single-level ACDF using a polyetheretherketone (PEEK) cage at our institution between January 2012 and December 2018. Our study population comprised 19 male and 21 female patients aged 24-70 years. The minimum follow-up period was 1 year. Twenty-seven patients had preoperative bone mineral density (BMD) data on dual-energy X-ray absorptiometry. Clinical parameters included sex, age, body mass index, smoking history, and prior medical history. Radiologic parameters included the C2-7 cobb angle, segmental angle, sagittal vertical axis, disc height, and total intervertebral height (TIH) at the preoperative and postoperative periods. Cage decrement was defined as the reduction in TIH at the 6-month follow-up compared to preoperative TIH. To evaluate the bone quality, Hounsfield unit (HU) value was calculated in the axial and sagittal images of conventional computed tomography. Results : Lumbar BMD values and cervical HU values were significantly correlated (r=0.733, p<0.001). We divided the patients into two groups based on cage decrement, and 47.5% of the total patients were regarded as cage decrement. There were statistically significant differences in the parameters of measuring the HU value of the vertebra and intraoperative distraction between the two groups. Using these identified factors, we performed a receiver operating characteristic (ROC) curve analysis. Based on the ROC curve, the cut-off point was 530 at the HU value of the upper cortical and cancellous vertebrae (p=0.014; area under the curve [AUC], 0.727; sensitivity, 94.7%; specificity, 42.9%) and 22.41 at intraoperative distraction (p=0.017; AUC, 0.722; sensitivity, 85.7%; specificity, 57.9%). Using this value, we converted these parameters into a bifurcated variable and assessed the multinomial regression analysis to evaluate the risk factors for cage decrement in ACDF. Intraoperative distraction and HU value of the upper vertebral body were independent factors of postoperative subsidence. Conclusion : Insufficient intraoperative distraction and low HU value showed a strong relationship with postoperative intervertebral height reduction following single stand-alone PEEK cage ACDF.

• 한국지리정보학회지
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• 제23권4호
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• pp.42-51
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• 2020

본 연구는 산림기본법 10조에 명시되어 있는 산림자원 및 임산물 수급의 장기전망을 통한 제6차 산림기본계획 수립을 지원하기 위하여 수행되었다. 우리나라 산지의 정의는 산지관리법에서 명시하고 있으며 산림 조성, 생산, 관리를 위해 필수 불가결한 요소로서 미래 산림자원의 변화를 예측하는데 가장 기본이 되기 때문에 미래의 산지면적 변화를 예측하는 것은 향후 계획수립을 위해 매우 중요하다. 그리하여 본 연구에서는 지대극대화 이론에 근거한 임업부가가치, 농업소득, 인구밀도를 종속변수로 하는 다항로지스틱 모형을 개발함으로써 미래의 산지면적, 농지면적, 도시 및 기타지의 면적 변화를 예측할 수 있었다. 그 결과 산지면적은 2026년까지 약 6,300천ha로 줄어들어 현재 대비 약 34천ha의 감소분이 발생할 것으로 전망되었으며, 이후 2027년부터는 반등을 시작하여 6,470천ha로 늘어나 약 172천ha의 증가분이 발생할 것으로 예측되었다. 이러한 산지면적의 증가는 임업부가가치의 증가와 관련이 있고, 농지면적의 증가는 농업소득의 증가, 그리고 도시 및 기타지의 증가는 인구밀도의 증가와 양의 상관관계를 가지고 있는 것으로 분석되었다. 그러나 산지면적의 주된 증가원인은 한계효과와 탄성치가 큰 인구밀도의 감소로 밝혀졌는데, 이는 저출산으로 인해 절대인구가 2032년부터 감소함에 따라 산지면적의 증가하기 때문인 것으로 나타났다. 또한 산지면적의 증가분은 도시 및 기타지에서 산지로 전환되는 면적이 대부분을 차지하는 것으로 나타났는데, 이것은 인구감소에 따른 도시 주변 지역의 인구 공동화 현상과 지방 소도시의 소멸 등과 같은 사회적인 문제에 기인하는 것으로 분석되었다. 이러한 산지의 증가를 산지관리 차원에서 살펴보면, 증가되는 산지면적은 지목상 임야 이외의 토지로부터 편입될 것으로 전망되기 때문에, 사후 산지관리법상의 산지로서 관리되기 위해서는 산림 관련 법령의 정비는 물론 변화에 대응한 새로운 산지관리 체계를 구축하는 것이 필요할 것으로 판단된다.

• Journal of Animal Science and Technology
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• 제60권4호
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• pp.7.1-7.5
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• 2018

Background: Mice are widely accepted research models of great clinical significance. Maintenance of laboratory mice breed is an essential aspect for performing research activities in various fields of science. Infanticide is one of the prominent causes of litter loss during maintenance of laboratory mice stock. The present study is an effort to monitor the effect of change in ambient temperature of female mice below the normal range on cannibalism and infanticide during early postparturition phase. Adult female Swiss albino mice have been divided into two groups of control and treatment. On the day of litter group one was maintained under controlled temperature conditions (minimum $20^{\circ}C$ to maximum $23^{\circ}C$) throughout, while female mice belong to group two have been exposed to variation of room temperature (maximum $15^{\circ}C$ to minimum $10^{\circ}C$ for two nights and one day) until 36 h postparturition. Results: The effects of temperature changes were observed on the infanticide behaviour of dams along with the survival of pups in early postparturition phase till 36 h after delivery. The significant statistical difference (P < 0.05) was reported in infanticide behaviour of dams when control and treatment group was compared. It is observed that decrement in surrounding temperature promotes decrement in the ambient body temperature of dams during early postparturition. It is proposed that alteration of hypothalamic homeostasis due to temperature change induces cannibalism and infanticide behaviour. Lack of thermoregulation during early postparturition creates the sense of insecurity, in-satiety, anxiety and stress. Conclusions: Authors strongly recommend the maintenance of body and surrounding temperature to prevent infanticidal behaviour and cannibalism within Swiss albino mice population. Further investigations are advisable to authenticate the active behavioural and biochemical pathway behind the phenomena.

• 농업과학연구
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• 제45권1호
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• pp.120-127
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• 2018

The rural labor force has gradually been decreasing due to the decrement of the farm population and the increment of the aging population. To solve these problems, it is necessary to develop and study autonomous agricultural machinery. Therefore, analyzing the dynamic behavior of vehicles in an autonomous agricultural environment is important. Until now, most studies on agricultural machinery, especially on ground vehicle dynamics, have been done by field tests. However, these field test methods are time consuming and costly with seasonal restrictions. A research method that can replace existing field test methods by using simulations is needed. In this study, we did basic research analyzing the effect of the travelling speed of a tractor on tire slip using simulation software. A tractor simulation model was developed based on field conditions following a straight path. The simulation was done for three ranges of speed: 20 - 30 km/h (considered the normal travelling speed range), 6 - 8 km/h (considered the plow tillage speed range) and 2 - 4 km/h (considered the rotary tillage speed range). The results of the simulation show that the slip ratio and slip angle values tended to increase as the traveling speed range of the tractor decreased. From the simulation results, it can be concluded that at low tractor speeds, it becomes more difficult to control the vehicle path. In future research, simulations will be done with various work environments such as a curved path as well as with various friction coefficient conditions, and the simulation results will be experimentally verified by applying them to an agricultural tractor.

• Asian-Australasian Journal of Animal Sciences
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• 제10권6호
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• pp.599-602
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• 1997

Fluctuation of fungal zoospores on agar strips were observed in the rumen of sheep fed three different levels of dietary concentrate, timothy hay: concentrate = 3:0 (AF diet), timothy hay: concentrate = 2:1 (MC diet), timothy hay : concentrate = 1:2 (HC diet) respectively. The number of zoospores on the strip was drastically decreased after morning feed with AF diet. The number was the highest at 0 h ($1.34{\times}10^2/cm^2$), then declined to $2.0{\times}10^3/cm^2$ at 9 h after feeding. In the rumen of animals fed MC diet, the number of zoospores decreased with time after feeding, although the decrement was slower than that with AF diet. During 0-3 h after feeding, number of zoospores was $1.6{\times}10^4/cm^2$. Although the number slightly decreased at 6 and 9 h, relatively high levels were maintained. It seems that the inducers for zoospore-release were maintained at relatively high concentration throughout incubation period. The fluctuation pattern of number of germinated zoospores was different in the rumen of animals fed HC diet from those of AF and MC diets. The number of zoospores was constantly maintained at lower level ($1.0{\times}10^3/cm^2$) than the other diets. For MC diet, continuous high number of germinated zoospores may be due to the continuous release of zoospores by hemes in timothy hay and concentrate feed, and by unknown mechanisms. Unlike AF diet which promoted relatively rapid decline of zoosporogenesis, supplementation of concentrate feed to the timothy hay did not promote such rapid decline of zoosporogenesis. It was suggested that release of inducers for zoosporogenesis from concentrate feed persisted longer time than from timothy hay. HC diet promoted the lowest zoospore production, suggested the lowest fungal population size in this experiment. These results show that an appropriate amount of concentrate may support fungal growth and stimulate zoosporogenesis in the rumen.

• 한국학교보건학회지
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• 제5권2호
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• pp.66-73
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• 1992

The objective of the study is to review the research materials for menarche including general characteristics of target population surveyed, mean age of subject, menarche experience rates of the subject and mean age at menarche, and to analyze secular trends of age at menarche in Korea from 1935 to 1992. The results of the study summarized as follows; 1. The range of age in the target pulation for menarcheal research was mainly 10-29 age groups, and most of them were middle, high school girls and college students. 2. There was positive relationship among mean age at menarche, level of menarche experiences rates and mean age of the subject(P<0.01). 3. In the relationship between the mean age at menarche and the level of menarche experience rate of the subject, the subject of study with higher menarche experience were more likely to be higher mean age at menarche than those with lower menarche experience rates. In case of menarcheal experience rates at 75-90 percent among the subject, the values of more and median were more close to the actual mean age at menarche under the assumption that all of the subject had experience menarche. 4. The trends of age at menarche during 1935-92 were linear decrement: Y = 85.93-0.036X in the whole country and Y = 91.35-0.039X in Seoul. The rates of secular diminution in age at menarche calculated to be about 4.3 months per decade in the nation-wide, and 4.6 months in Seoul during the periods. 5. To analyze the secular trends in menarcheal age, the researcher should set up criterians including the range of age in target population, the level of menarcheal experience rate and the regional characteristics.

• 보건교육건강증진학회지
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• 제15권2호
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• pp.199-215
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• 1998

The health care environment exerts tremendous influence on community health practices. Here the author mention several major factors that will influence the future plan for health service and health education; that is, economic problem, the issues of decrement of infectious disease, increment of chronic degenerative disease due to natural increase of the elderly, increased frequency of traffic and industrial accidents and the issues of medical-technological advances etc. Therefore, special efforts by health personnel should be made to develop health education and health promotion strategies on a community-wide basis. Accordingly, the flexible accessibility, convenient availability, guaranteed medical service, sufficient supply of health information, and rapidly available medicaid service for special population such as the elderly, the handicapped, the disabled and the poor are considered. Also, the financial support from the central government and local self-government and active participation of health consumer to health service are needed in Korea, The role of the health personnel is to elicit, facilitate and maintain health promoting behavior with his and her assurance for health consumers being competent and supported in the voluntary choice of their health promoting activities. The health promoting activities such as the above mentioned will be produce escalation of their life Quality among Koreans.

• Tuberculosis and Respiratory Diseases
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• 제45권3호
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• pp.495-502
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• 1998

연구배경: 결핵유병률은 사회경제적 여건과 갚은 관련성을 가지지만 국내에서 특정 사회집단에서의 결핵유병률에 대한 연구는 부족하다. 따라서 본 연구에서는 대학신입생이라는 특정 집단에서 지난 10년간의 유병률 변화를 알아보았다. 방 법: 1988년에서 1997년까지 서울대학교 신입생을 대상으로 흉부방사선 소견상 활동성 폐결핵의 유병률을 조사하여 이를 본 연구보다 10년 전에 같은 방법으로 얻어진 대학신입생에서의 유병률 보고와 비교하고, 전국민결핵실태조사결과 중 동일연령군의 유병률과 비교하였다. 결 과: 지난 20년간 서울대학교 신입생의 결핵유병률은 1977년 2.5%, 1980년 1.7%, 1985년 0.6%, 1990년 0.25%, 1995년 0.07% 로 꾸준하게 감소하였다. 이를 동일연령 일반인구와 비교했을 때 1985년, 1990년은 서울대학교 신입생에서 유의하게 유병률이 낮았으나 1995년에는 유의한 차이가 없었다. 결 론: 서울대학교 학생의 결핵유병률은 계속 감소하고 있으며, 이를 동일연령 전국 유병률과 비교하면 점차 두군의 유병률이 근접함을 알 수 있었다. 이는 전반적인 사회경제적 수준의 향상과 관련된 것으로 생각된다.