Capturing Heterogeneous Regressor Configurations in a Choice Model

Ha, Young-Won,Kim, Jin Gyo 서강대학교 경영학연구원 2004 서강경영논총 Vol.15 No.1

This paper empirically investigates whether consumers use different decision variables (covariates, regressors) for their purchase decisions in a supermarket shopping setting. To this end, this paper presents a new methodology that allows one to identify relevant regressors for each consumer. The proposed model was fitted to a scanner panel data set and we found extremely strong evidence supporting large variation in terms of relevant repressors configurations across consumers.

전기 방열기가 국화재배온실의 난방에 미치는 영향

서원명 ( Won Myung Suh ),임재운 ( Jae Woon Leem ),김영주 ( Young Ju Kim ),민영봉 ( Young Bong Min ),김현태 ( Hyeon Tae Kim ),허무룡 ( Moo Ryong Huh ),윤용철 ( Yong Cheol Yoon ) 경상대학교 농업생명과학연구원(구 경상대학교 농업자원이용연구소) 2010 농업생명과학연구 Vol.44 No.4

경상대학교 교내에 설치되어 있는 1-2W형 온실을 대상으로 전기 방열기를 이용하여 국화 재배온실의 난방효과를 검토한 결과는 다음과 같다. 실험기간동안 최고, 평균 및 최저 외기온은 각각 -3.8~21.3℃, -5.2~16.1℃ 및 -12.5~14.4℃ 정도의 범위로 나타났으며, 온실 내외의 평균상대습도 각각 43.5~98.6% 및 35.2~100%로 나타났다. 12월 중순부터 2월 상순까지 최저 외기온은 대략 -5.0~-10.0℃ 전후로 나타나 진주기상대의 최근 자료와 비교하면 상대적으로 최저기온이 낮게 나타나는 경향이 있었다. 야간의 경우, 방열기 직하부의 엽온이 방열기 중간 지점에서 측정한 엽온 보다 크게 2~3℃정도 높게 나타나거나 또는 미미하지만 약간 높게 나타나는 경향이 있었다. 근권부의 경우, 직하부나 중간 지점에서의 온도 차이는 거의 없는 것으로 나타났고, 근권부의 최고온도와 기타 최고 온도의 발생 시점을 보면, 약 2시간정도의 지체현상이 있음을 알 수 있었다. 그리고 실험기간동안 난방에 소요된 총 소비전력량, 공급에너지 및 총 난방비는 각각 2,800kWh, 2,408,000kcal 및 112,000won 정도였다. 화석연료인 경유로 난방할 경우, 총 난방비는 224,500won 정도였다. 방열기를 이용하여 난방할 경우, 난방비를 약 50% 정도 줄일 수 있을 것으로 판단되었다. An analysis in heating effects of an electric radiator located in a 1-2W type chrysanthemum (3 cultivars) cultivation greenhouse installed in Gyeongsang National University drew the following conclusions. During the experiment period, the highest, average, and the lowest outside temperatures were in the ranges of -3.8~21.3℃, -5.2~16.1℃ and -12.5~14.4℃, respectively, and the average relative humidity inside and outside the greenhouses were in the ranges of 43.5~98.6% and 35.2~100%, respectively. From mid-December to early February, the lowest outside temperature was recorded as approximately -5.0~-10.0℃, which showed that it tended to be relatively lower than the temperatures recorded at the Jinju Meteorological Observatory. During the night, the leaf temperature measured directly under the radiator tended to be higher by 2~3℃ than that those at the middle point of the radiator, or higher by anegligible amount. In the case of root zone temperature, it was found that there was almost no difference between temperatures of the part directly under and the middle point, and the time when the highest temperature of root zone and other highest temperatures took place showed that there was about a 2-hour delay phenomenon. The total electricity consumption, energy supply and total heating cost during the experiment period were 2,800 kWh, 2,408,000 kcal and 112,000 won, respectively. When diesel, a kind of fossil fuel, was used as heating oil, the total heating cost was around 224,500 won. It was estimated that the total heating cost could be reduced by around 50% if a radiator was used.

『선문정로(禪門正路)』에 나타난 여래선(如來禪)의 특성

김원영 ( Kim Won-young ) 성철사상연구원 1999 백련불교논집 Vol.9 No.-

In the Seonmun-jeongno(禪門正路), theory of Sudden Enlightenment and Sudden Cultivation(頓悟頓修) is recommended as a proper way to attain enlightenment, of which the Yeorae-Seon(Zen transmitted by Tathāgatha, 如來禪) is stressed to be practiced. Though the meditation by Koan(公案) originally suggested by Tai-hui(大慧) in Song dynasty, the characteristic of Yeorae-Seon that especially is described in the Seonmun-jeongno also has to be examined since it has been transmitted longtime ago. Here, we also examine the view on the Yeorae-Seon by Song-chol(性徹), Won-hyo(元曉), and Shen-hui(神會) together. Specially the standpoint of Won-hyo look to compromise the one of Song-chol. In his Commentary on Vajrasamadhi Sutra, Won-hyo alluded that the Yeorae-Seon means the entering into the Tathāgatha-garbha, which is accomplished by the Threefold Vision of Unattachedness, or Mahayanic View of Emptiness. Through the learning of the next two steps, that is, the Listening of wisdom or the First Unattachedness and the Thinking on Wisdom or the Second Unattachedness, the Third Unattachedness or Cultivation of Wisdom would be allowed. Cultivation of Wisdom is to be arise from the proper state of meditation, so it should be refered to the Giving Up the Illusive Thinking. From the standpoint of the theory of Ten Bhumis, this can be applied to the First Bhumi. For Won-hyo, Yeorae-Seon denotes the Samadhi that is accomplished at the stage of Boddhisattva’s First Bhumi. Because this state is the same with the tranquility and turmoil of everyday routine, from the point of Three Stage, this is the sameness of move-and-stillness. For Kui-feng(圭峯), Yeorae-Seon is to practice meditation after understanding on the fact that the nature of Tathāgatha-garbha is originally empty and tranquil. This is what is called theory of Sudden Enlightenment and Gradual Cultivation(頓悟漸修). In this context, the knowledge is more important. Ji-nul(知訥) said that the enlightenment can be attainable in the First Step of Ten Stage, thus it means to say that he enters the Yeorae-Seon. Once this stage was called as the Insight into the Nature, the ortho-praxis of Zen Buddhism but, this view is strongly criticized in the Seonmun-jeongno. By the way, Yeorae-Seon(Zen Buddhism of Tathāgatha) and Josa-Seon(Zen Buddhism of Patriarch) have often been involved in the argument about whether the both of them are same or not, which was originally derived from the discussion by Yang-shan(仰山) and Xiang-yan(香嚴). For this discussion Song-chol insists that the dialogue looks superficially to tell the differences between Yeorae-Seon and Josa-Seon, but reflects the equality of them. Song-chol also said that this is the very essence of the Zen. It is can be said that Yeorae-Seon described in the Seonmun-jeongno would be available from the very beginning of Koan practice to the ultimate state of Mindlessness. Thus, there are different views on the Yeorae-Seon. First, Ji-nul told that it is accomplished at the First Stage, for Won-hyo it is at the First Bhumi of Boddhisattva, and for Song-chol it is at the Ultimate Enlightenment. However, when it comes to the Utilization of Mindfulness and Concentration together, Song-chol would get it to correspond to Koan Practice.

중증 외상 환자의 골반골절에서 경피적 혈관 색전술과 Young과 Burgess 분류의 상관관계

차용한 ( Yong Han Cha ),설영훈 ( Young Hoon Sul ),김하용 ( Ha Yong Kim ),최원식 ( Won Sik Choy ) 대한외상학회 2015 大韓外傷學會誌 Vol.28 No.3

Purpose: Immediate identification of vascular injury requiring embolization in patients with pelvic bone fracture isn’t an easy task. There have been many trials finding indicators of embolization for patients with pelvic bone fracture. Although Young and Burgess classification is useful in decision making of treatment, it is reported to have little value as indicator of embolization in major trauma patients. The aim of this study is to find out Young and burgess classification on predicting vessel injury by analzyng pelvic radiograph taken from major trauma patients with pelvic bone fracture. Methods: Among major trauma patients with injury severity scores (ISS) higher than 15 who visited our emergency room from January 2011 to June 2014, 200 patients were found with pelvic bone fracture in trauma series and thus pelvic CT angiography was taken. Setting aside patients with exclusion criteria, 153 patients were enrolled in this study for analysis of Young and Burgess classification. Results: The most common mechanism of injury was lateral compression in both groups. There was no statistical significant difference in Young and Burgess classification (p=0.397). The obturator artery was the most commonly injured artery in both groups. Six patients had more than one site of bleeding. Conclusion: Prediction of transcatheter angiographic embolization using Young and Burgess classification in severe trauma patients is difficult and requires additional studies. [ J Trauma Inj 2015; 28: 144-148 ]

젊은 성인에서 흡연에 의한 상완동맥 내피기능의 부전에 관한 연구

이상철,권영주,방덕원,이선해,이보영,김지욱,김영훈,온영근,현민수,김성구 순천향의학연구소 2002 Journal of Soonchunhyang Medical Science Vol.8 No.1

Background and Objectives : Cigarette smoking is a major factor and the most modifiable risk factor for atherosclerosis. Endothelial dysfunction is an early event in atherosclerosis, before the structural change of the systemic arteries. We hypothesized that endothelial dysfunction might be present in the systemic arteries of young adult smokers and that this might be dose-dependent phenomenon. Therefore, we try to certify that smoking is associated with endothelial dysfunction in healthy young adults without other risk factor of atherosclerosis. Subjects and Methods : we studied noninvasively 29 subjects aged 3 to 4 decades without other risk factor of atherosclerosis, they were composed of the two groups, current smokers(n=15) and nonsmokers(n=14). Smoking history varied from 3 to 20 pack years. Using high-resolution ultrasound, vessel diameter and mean flow rate were measured at rest, during reactive hyperemia(with flow-mediated endothelium-dependent dilation), and after sublingual nitroglycerin(NG-induced endothelium-independent vasodilation). Result : Flow mediated endothelium dependent dilation was observed in the control subjects (9.4±3.44%) but was impaired in the smokers(5.8±2.51%)(p=0.004). NG-induced endothelium independent dilation is no difference in all subjects. Conclusion : Cigarette smoking is associated with endothelial dysfunction in healthy young adults.

Elderly kidney transplant recipients have favorable outcomes but increased infection-related mortality

임정훈,Lee Ga Young,Jeon Yena,Jung Hee-Yeon,Choi Ji Young,CHO, JANG-HEE,Park Sun Hee,김용림,Kim Hyung-Kee,Huh Seung,유은상,Won Dong Il,Kim Chan-Duck 대한신장학회 2022 Kidney Research and Clinical Practice Vol.41 No.3

Background: The number of elderly patients with end-stage kidney disease has been increasing, but the outcomes of kidney transplants (KT) remain poorly understood in elderly patients. Therefore, we evaluated the clinical outcomes of elderly KT recipients and analyzed the impact of elderly donors. Methods: This retrospective cohort study included patients who underwent KT between 2000 and 2019. KT recipients were divided into four groups according to a combination of recipient and donor age (≥60 or <60 years); elderly recipients: old-to-old (n = 46) and young-to-old (n = 83); young recipients: old-to-young (n = 98) and young-to-young (n = 796). We compared the risks of mortality, graft failure, and acute rejection between groups using Cox regression analysis. Results: The incidence of delayed graft function, graft failure, and acute rejection was not different among groups. Annual mean tacrolimus trough level was not lower in elderly recipients than young recipients during 10-year follow-up. Mortality was significantly higher in elderly recipients (p = 0.001), particularly infection-related mortality (p < 0.001). In multivariable Cox regression analysis, old-toold and young-to-old groups had increased risk of mortality (adjusted hazard ratio [aHR], 2.89; 95% confidence interval [CI], 1.14– 7.32; p = 0.03; aHR, 3.06; 95% CI, 1.51–6.20; p = 0.002). However, graft failure and acute rejection risks were not increased in elderly recipients. Conclusion: In elderly recipients, graft survival and acute rejection-free survival were not inferior to those of young recipients. However, mortality, especially risk of infection-related death, was increased in elderly recipients. Thus, low immunosuppression intensity might help decrease mortality in elderly recipients.

노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

Comparison of trophic factors changes in the hippocampal CA1 region between the young and adult gerbil induced by transient cerebral ischemia.

Yan, Bing Chun,Park, Joon Ha,Kim, Sung Koo,Choi, Jung Hoon,Lee, Choong Hyun,Yoo, Ki-Yeon,Kwon, Young-Geun,Kim, Young-Myeong,Kim, Jong-Dai,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2012 Cellular and molecular neurobiology Vol.32 No.8

<P>In the present study, we investigated neuronal death/damage in the gerbil hippocampal CA1 region (CA1) and compared changes in some trophic factors, such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), in the CA1 between the adult and young gerbils after 5 min of transient cerebral ischemia. Most of pyramidal neurons (89%) were damaged 4 days after ischemia-reperfusion (I-R) in the adult; however, in the young, about 59% of pyramidal neurons were damaged 7 days after I-R. The immunoreactivity and levels of BDNF and VEGF, not GDNF, in the CA1 of the normal young were lower than those in the normal adult. Four days after I-R in the adult group, the immunoreactivity and levels of BDNF and VEGF were distinctively decreased, and the immunoreactivity and level of GDNF were increased. However, in the young group, all of their immunoreactivities and levels were much higher than those in the normal young group. From 7 days after I-R, all the immunoreactivities and levels were apparently decreased compared to those of the normal adult and young. In brief, we confirmed our recent finding: more delayed and less neuronal death occurred in the young following I-R, and we newly found that the immunoreactivities of trophic factors, such as BDNF, GDNF, and VEGF, in the stratum pyramidale of the CA1 in the young gerbil were much higher than those in the adult gerbil 4 days after transient cerebral ischemia.</P>

우리나라 노인여성의 골다공증성 척추골절로 인한 경제적 부담 추계

강혜영,강대룡,장영화,박성은,최원정,문성환,양규현,Kang, Hye-Young,Kang, Dae-Ryong,Jang, Young-Hwa,Park, Sung-Eun,Choi, Won-Jung,Moon, Seong-Hwan,Yang, Kyu-Hyun 대한예방의학회 2008 예방의학회지 Vol.41 No.5

Objectives : To estimate the economic burden of osteoporotic vertebral fracture (VF) from a societal perspective. Methods : From 2002 to 2004, we identified all National Health Insurance claims records for women ${\geq}50$ years old with a diagnosis of VF. The first 6-months was defined as a "clearance period," such that patients were considered as incident cases if their first claim of fracture was recorded after June 30, 2002. We only included patients with ${\geq}$ one claim of a diagnosis of, or prescription for, osteoporosis over 3 years. For each patient, we cumulated the claims amount for the first visit and for the follow-up treatments for 1 year. The hospital charge data from 4 hospitals were investigated to measure the proportion of the non-covered services. Face-to-face interviews were conducted with 106 patients from the 4 study sites to measure the out-of-pocket spending outside of hospitals. Results : During 2.5 years, 131,453 VF patients were identified. The patients had an average of 3.38 visits, 0.40 admissions and 6.36 inpatient days. The per capita cost was 1,909,690 Won: 71.5% for direct medical costs, 20.6% for direct non-medical costs and 7.9% for indirect costs. The per capita cost increased with increasing age: 1,848,078 Won for those aged 50-64, 2,084,846 Won for 65-74, 2,129,530 Won for 75-84and 2,121,492 Won for those above 84. Conclusions : Exploring the economic burden of osteoporotic VF is expected to motivate to adopt effective treatment options for osteoporosis in order to prevent the incidence of fracture and the consequent costs.

Sophora flavescens의 뿌리에서 유래한 Cholinesterase 저해 화합물

장원희, 트란홍광, 김장훈, 양서영, 김영호 충남대학교 약학대학 의약품개발연구소 2021 藥學論文集 Vol.36 No.-

Searching for cholinesterase inhibitory compounds from natural products is important to de- velop therapeutic agents for Alzheimer’s disease. Our previous research on the chemical components of Sophora flavescens roots resulted in the isolation of twelve flavonoids, kushenol E (1), maackiain (2), 8-prenylkaemperol (3), 8-prenylnaringenin (4), kushenol L (5), kushenol A (6), kushenol C (7), kushenol B (8), sophoraflavanone G (9), kushenol H (10), isoxanthohumol (11) and kurarinone (12) and their structures were elucidated by spectroscopic methods. Inhibitory effect of cholinesterase were tested using the Ellman's method. Most flavonoid compounds showed good inhibitory activities on cholinesterases. Kushenol E (1) and sophoraflavanone G (9) showed good inhibitory activities on acetylcholinesterase with IC50 values of 3.75 and 4.14 μM and butyrylcholinesterase with IC50 values of 2.00 and 0.75 μM, respectively. In addition, a kinetic analysis revealed that kushenol E (1) was non-competitive inhibitor with Ki value of 0.77 μM on acetylcholinesterase and 0.16 μM on butyrylcholinesterase, whereas sophoraflavanone G (9) was mixed type inhibitior with Ki value of 9.42 μM on acetylcholinesterase and 0.81 μM on butyrylcholinesterase. These findings suggest that flavonoid compounds from S. flavescens roots are potential cholinesterase inhibitors.