• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.411-425
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• 2021

Accelerated failure time (AFT) model represents a linear relationship between the log-survival time and covariates. We are interested in the inference of covariate's effect affecting the variation of survival times in the AFT model. Thus, we need to model the variance as well as the mean of survival times. We call the resulting model mean and variance AFT (MV-AFT) model. In this paper, we propose a variable selection procedure of regression parameters of mean and variance in MV-AFT model using penalized likelihood function. For the variable selection, we study four penalty functions, i.e. least absolute shrinkage and selection operator (LASSO), adaptive lasso (ALASSO), smoothly clipped absolute deviation (SCAD) and hierarchical likelihood (HL). With this procedure we can select important covariates and estimate the regression parameters at the same time. The performance of the proposed method is evaluated using simulation studies. The proposed method is illustrated with a clinical example dataset.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.514-514
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• 2022

쌀 공급과잉이 사회적 문제가 되면서 논에 타작물 재배를 위한 논의 다각적 활용 시스템 구축이 매우 중요해지고 있다. 정부는 이러한 논의 다각적 활용을 위해 2020년에 우리나라 최초의 농지범용화 시범사업 지구를 선정하였다. 전북 김제시 옥성지구는 농지범용화 시범사업 지구로 선정되어 용·배수로 정비가 실시되었다. 따라서 본 연구에서는 전북 김제시 옥성지구 용배수로 정비의 효과를 살펴보기 위해 시범사업 전후의 주요 영농여건 변화 실태를 살펴보았다. 이를 위해 본 연구에서는 농업경영체 DB, 흙토람 등을 이용해 옥성지구 일대 수혜 필지와 비수혜 필지를 추출하고, 각 필지별 실제 경작자 명단을 작성 후 1:1 면담 조사를 실시하였다. 옥성지구 농지범용화 시범사업 면적은 총 50.4ha인데, 169개 필지로 구성되었다. 이 중에서 129개 필지의 총 69명의 경작자 명단이 작성되었다. 그리고 본 연구의 조사에 총 30명이 참여했고, 이 가운데 수혜구역과 비수혜구역의 논을 동시에 경작하고 있는 9농가를 대상으로 논의 다각적 활용을 위한 용·배수 정비 전후의 성과를 조사하여 분석하였다. 첫째, 9농가는 모두 논콩을 재배하고 있다. 이들의 평균 논콩 재배면적은 2020년 1.76ha에서 2021년에는 2.22ha로 증가했다. 그리고 논콩 10a 당 생산량을 살펴보면, 2020년 355.8kg/10a에서 2021년에는 567.2kg/10a로 사업 전후 논콩 단수가 211.4kg/10a 증가했다. 평균 우리나라 전국 콩의 생산량이 203kg/10a, 전북 248kg/10a(2021년 기준)인데 반해 농지범용화 시범사업 지구의 논콩 생산성은 전국 평균보다 높은 것을 알 수 있다. 따라서 논의 다각적 활용을 위한 용배수로 정비를 통해 평균 단수는 211.4kg/10a 증가하기 때문에, 용배수로 정비는 논타작물 생산성 향상에 기여하고 있는 것을 알 수 있다. 둘째, 논의 다각적 활용을 위한 용배수로 정비 이전에 평균 침수 시간은 24시간 이내였다. 이러한 침수로 인해 논콩 재배농가들은 대부분 논타작물 재배의 어려움을 겪었다. 하지만 용배수로 정비 후 평균 침수 시간은 3시간 이내로 단축되었다. 이러한 침수시간 단축은 논콩 생산비 절감으로 이어져 용배수로 정비 후 시범사업 수혜 농가들의 논콩 직접생산비는 10a당 210,200원으로 전년 대비 34,250원/10a 감소하였다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.51-51
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• 2020

콩의 원산지는 만주를 중심으로한 동북아시아를 원산지로 추정하고 있으며, 동아시아인 한국, 중국, 일본의 주요 식재료로 다양하게 이용되어왔다. 콩은 단백질과 지방의 공급원으로서 뿐 아니라 최근에는 콩의 생리활성 물질이 항암효과, 골다공증, 신장질환과 같은 질병예방에도 효과가 있는 것으로 알려지면서 활용가능성이 높아지고 있다. 본 연구는 유전자원센터에 보존 중인 콩 수집단에서 농업형질, 기초정보 등을 토대로 핵심집단을 작성하고 그 중 한국, 중국, 일본 수집단 각 425, 93, 42자원의 개화일수, 생육일수, 주당협수, 100립중, 주당수량과 같은 양적형질을 비교하였다. 개화일수와 생육일수는 중국수집 자원에서 평균38일, 107일로 가장 빠르며, 한국수집 자원은 평균 53일, 127일로 가장 늦었다. 협당립수는 중국수집 자원에서 협당 평균3립으로 가장 많았으며, 한국과 일본 수집자원은 각 2.3과 2.4립으로 유사하였다. 주당협수는 한국 수집자원에서 주당 평균 327.4개로 가장 많고 일본이 248.0개 중국이 224.4순으로 조사되었다. 100립중은 일본 수집 자원이 평균 33.6g으로 대립이 많고 한국 26.5g , 중국 21.1g 이었다. 주당수량은 한국 수집자원이 평균 119.8g, 일본 84.2g, 중국 76.8g순이었다. 이들 5개 양적형질을 토대로 군집분석한 결과 한국 자원은 대다수가 C3 그룹에 속하고, C1 그룹에 일부가 속하였으며, 일본 자원은 C3 그룹과 C2 그룹에, 중국 자원은 C2 그룹에 속하여 한국과 일본자원이 유사하고 중국자원과는 차이를 보이는 것으로 나타났다. 이러한 특성조사 결과는 자원의 수집, 도입시 다양성 확보를 위한 기초정보로 이용할 수 있다.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.261-270
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• 1989

The present study is intended to observe the chronologic changes of experimental sparganosis by histopathological observation and detection of circulating anti-sparganum IgG antibody using ELISA. Each of 25 mice was infected with aye spargana, and they were examined after 1, 2, 4, 10 weeks or 6 months from infection. The followings are summarized results. - 1. The plerocercoids were detected in the subcutaneous tissue of the trunk, neck or axilla, but a few often extended into the skeletal muscle. The recovery rates were 72% at the first week, 80% at the second week, 95% at the fourth week, 92% at the tenth week and 100% at .the sixth month. The larvae grew slowly in both length and weight until 6 months. 2. Histopathologically, most of the larvae were observed alive in the soft tissue or skeletal muscle. Numerous eosinophils, neutrophils, Iymphocytes and plasma cells were infiltrated focally around the worms by the second week, but they surrounded the worms to form a layer of inflammatory reaction after 4 weeks of infection. Also histiocytes and fibroblasts began to appear around the inflammatory cells at 4 weeks. After 10 weeks, the worms encircled by a thin fibrous layer were found. After 6 months, the worms were surrounded by either fibrous tissue or active inflammatory cells. The inflammation looked more severe in the tracks left by the worms, rather than around the worms. 3, The level of anti-sparganum IgG antibody in the serum showed an increase by the fourth week, and a rapid and continuous increase was observed thereafter by the tenth week after infection. The high level of the IgG antibody was maintained up to 6 months forming a plateau curve. The present results suggest that the tissue reaction and antibody production in subcutaneous sparganosis become distinctive by the fourth week after infection.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.506-507
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• 2009

• Ceramist
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• v.7 no.1
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• pp.21-29
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• 2004

인류의 평균수명이 지속적으로 연장되고 삶의 질을 향상시키려는 욕구가 증가함에 따라 고급 의료기술에 관한 관심이 크게 증가하고 있다. 기존에는 치아가 결손되었을 때 브릿지라는 보철물이나 틀니를 사용하였으나 인접 치아 및 잇몸에 손상을 주는 부작용이 있었다. 최근 널리 보급되고 있는 임플란트 시술법은 결손된 치아 자리에 인공치아를 심는 방법으로서, 치아가 소실된 부분에 치아뿌리 모양의 임플란트를 매식하여 턱뼈에 고정시킨 후 여기에 크라운을 연결하여 보철을 완성한다.(중략)

• Digital Contents
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• no.8 s.147
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• pp.18-22
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• 2005

LBS가 이동통신사업자들의 주 수익원으로 급성장해 기존 무선인터넷 매출의 대부분을 차지했던 벨소리, 캐릭터 다운로드 등의 서비스를 제치고 모바일 콘텐츠의 핵심 서비스로 자리 잡아 가고 있다. LBS는 연 평균 100�200%의 고속 성장이 예상되면서 각 사업자들은 LBS를 차세대 유망사업으로 지목, 시장 확대를 위해 공격적인 사업을 펼쳐나가고 있다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.188-194
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• 2007

The relationships between pine mushroom emergence and meteorological factors were analyzed with three years (from 2003 to 2005) of measurement data at Yangyang site, in order to evaluate the effect of micrometeorological environment on pine mushroom production. fine mushroom was daily monitored and collected in the survey area during the its producing period (approximately one month). Pine mushroom production was highest in 2005 with the meteorological conditions of high temperature and frequent rainfalls in October. The production was lowest in 2004 due to dry conditions from mid September to late October, The meterological factors related to humidity (i.e., relative humidity, soil water content, and precipitation) were better correlated than those related to temperature (i.e., air and soil temperature, soil heat flux and solar radiation) with pine mushroom production. However, all of the correlation coefficients were statistically insignificant with values ranging from 0.15 to 0.46. Such poor correlations may be attributed to various other environmental conditions (e.g., topography, soil, vegetation, other fungi, the relationship between pine mushroom and pine forest) affecting pine mushroom production. We found that a mycelium requires a stimulation of low temperature (of three-day moving average) below $19.5^{\circ}C$, in order to farm a mushroom primordium which grows to pine mushroom after 16 days from the stimulation. We also found that the pine mushroom production ended when the soil temperature (of three-day moving average) fell below $14.0^{\circ}C$.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.346-352
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• 2012

This study compared and analyzed fetus, newborn infant, and delivery methode of 141 women who received medical service from the first examination to the delivery in an obstetrics and gynecology specialized hospital located in Gwangmyeong, Gyeonggi-do from Jan. 2010 to Dec. 2010 and had a regular delivery after 37 weeks of pregnancy (73 non-employed and 68 employed women), depending on employment state of the subjects. The following are the results derived from the study. 1. The weight of the mothers after 37 weeks of pregnancy and the average gestational age was no statistical difference depending on the employment state. 2. In 37 weeks, the average fetal weight in the non-employed group was $2.90{\pm}0.27kg$ and the rate of small for gestational age infants was 2.75%. Meanwhile, the average fetal weight in the employed group was $2.76{\pm}0.28kg$ and the rate of small for gestational age infants was shown to be 10.3%. It is known that the fetal weight of the non-employed group was significantly higher for 37 weeks of pregnancy (p<0.05). 3. The newborn infant weight of the non-employed group was $3.42{\pm}0.43kg$ in average while that of the employed group was $3.18{\pm}0.35kg$. It is known that the newborn infant weight of the non-employed group was significantly higher (p<0.05). 4. In terms of delivery method, cesarean constituted 32.9% in the non-employed group while constituting 16.2% for the employed group. It is known that cesarean was shown to be significantly higher among the non-employed group (p<0.05).

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.2
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• pp.147-154
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• 2006

Purpose: To analyze the effectiveness of the treatment with the stretching exercise in the patients with iliotibial band (ITB) friction syndrome. Materials and Methods: 22 patients with ITB friction syndrome were treated with the stretching exercise of the ITB. The criterion for determining the good result is more than 75% recovery according to the classification of success of treatment. We analyzed the differences of the duration of treatment at which the good result it achieved according to sincerity of the stretching exercise. The sincerity of the exercise is defined at performing more than 50% of the exercise that we prescribed. Results: Of 22 patients, there were good results in 19 cases (87%) within 8 weeks after the treatment. Except for 3 cases who did not achieved good results, the average duration of the treatment is 28.1 days. In patients with good results there was no statistical significance for the relationship between the duration of symptoms before diagnosis (average 25.6 days) and the duration of the treatment (average 28.1 days). In comparison with the group who performed the exercise sincerely and the group who did not, the average duration of the treatment if 23 days and 32.7 days respectively and there was significant difference between the two groups. Conclusion: The stretching exercise in ITB friction syndrome was helpful in reducing the duration of treatment.