電子商去來의 擴散과 價格構造, 企業戰略

崔善奎,李明豪,趙伯濟 서울大學校經濟硏究所 2001 經濟論集 Vol.40 No.4

이 글에서는 최근 전자상거래의 비중이 높아짐에 따라 경제학의 주요 연구대상인 가격구조, 시장의 효율성, 기업의 전략 측면에서는 어떤 이슈가 생성·연구되고 있는지 살펴보고 있다. 이 논문에서 다루고 있는 주요 내용은 다음과 같다. 소비자의 탐색비용이 낮아짐에 따라 전자상거래에서 팔리고 있는 제품의 전반적인 가격수준은 오프라인에 비해선 낮아지고 있다. 전자상거래가 소비자 수요의 가격탄력성에 미치는 영향은 양면적으로 보인다. 전자상거래의 가격구조에서 흥미로운 사실은 오프라인에 비해서 동일 제품에 대한 가격분산의 폭이 크다는 것이다. 전자상거래가 확산되면서 가격경쟁이 벌어질 경우 디지털 정보재화시장에서의 가격은 한계비용인 영에 근접하기 쉽다. 기업들은 가격경쟁을 회피하는 방안으로 여러 가지 차별화전략을 구사하게 되고, 새로운 중계기관이 생겨나고 있다. 또 기존의 예상과는 구매자-판매자 관계는 시장 지향적이라기 보다는 위계 지향적인 관계가 주류를 이루고 있는 것으로 나타난다. 인터넷의 등장과 전자상거래의 확산으로 기업전략 측면에서 제품의 효과적인 개인화 방법, 브랜드 관리기법, 인터넷 광고의 효과성, 전자상거래 하에서의 여러 혁신적인 가격차별전략(경매가격, 실시간 동적 가격차별), 기존의 유통채널과 온라인 유통채널 간의 갈등(channel conflict) 등의 문제가 나타나고 있다.

관절염 대상자의 건강상태 조사 : 일개 도ㆍ농 복합시를 중심으로

이은희,최선하,서길희,소애영,이경숙,최정숙,고경덕,김명천,박현자,백승리,유보비,윤현숙,이애란,이명희,이은숙,임영옥,정복녀,이영숙 대한류마티스 건강전문학회 2001 근관절건강학회지 Vol.8 No.2

The Purpose of this study was to investigate the health status and to examine the relationship between health related variables of the clients with arthritis. This descriptive-correlational study was measured physical health status(pain, fatigue, physical disability, joint flexibility) and psycho-social health status(social function disability, self-efficacy, depression) . The clients were consisted of 127 arthritis clients who were randomly selected from health center, 2 sub health center and 6 primary health care center in Wonju City. The data was collected from November 2000 to January 2001. The results of the study analyzed using a SPSS win were as follows : 1) The subjects' average age was 64.81 years old(female : 86.6%, male : 13.4%). 2) In physical health status, the average score of fatigue was 63 scores and pain was 69.77 Physical disability score was higher than total disability score. In psycho-social disability, housekeeping management disability score was higher than social function disability score. In psycho-social health status, the average score of self-efficacy was 70.86 and the subjects have higher level of depression, more than 20 scores. 3) On Pain sites, almost of subjects complained of a knee joint pain. The waist, wrist, and shoulder joint Pain were followed. The numbers of Pain site were 8.3 Per individuals 4) The flexibility of knee and shoulder joint were lower than another joints. 5) Correlation with fatigue, pain, physical disability, social disability, self-efficacy and depression was revealed highly significant. We suggest that health Promotion program considering our research results should be provided for arthritis clients in community level .

심인성 어지럼증 환자의 정신과적 증상에 관한 연구

이경규,이지영,김현우,이정엽,백기청,김재일,이근호 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.5

연구목적 : 어지럼증을 호소하는 환자들 중에 심인성 어지럼증 환자가 상당수 있다는 것은 알려져 있고, 이러한 심인성 어지럼증과 동반되는 정신질환으로는 불안장애, 우울장애, 인격장애 등이 있다. 이에 본 연구에서는 심인성 어지럼증 환자들의 빈도와 정신과적 증상을 알아보고자 하였다. 방 법 : 어지럼증 환자들에게 평형검사, 자세운동측정검사, 자세변화검사, caloric testing을 시행하여 심인성, 말초성 및 중추성의 3군으로 분류한 후 각각 14명, 16명, 32명을 대상으로 하였다. 대상환자들에게 한국판 Beck 우울척도검사(K-BDI), Spielberg의 상태-특성 불안검사(STAI). 간이정신진단검사(SCL-90-R)를 이용하여 정신과적 증상을 측정하여 이들 세 군을 비교분석하였다. 결 과 : 1) 심인성 어지럼증을 가진 환자는 어지럼증을 나타내는 환자 총 62명중에서 14명으로 22.6%를 차지하였다. 2) K-BDI에 따른 세 군간의 비교에서는 세 군간에 유의한 차이를 보이지 않았다. 3) STAI에 따른 세 군간의 비교에서 상태불안(STAI-S) 및 특성불안(STAI-T) 모두에서 세 군간에 유의한 차이를 보이지 않았다. 4) SCL-90-R에 따른 세 군간의 비교에서는 9개의 척도 중에서 공포불안척도에서만 중추성 어지럼증군이 47.56±6.90, 말초성 어지럼증 군이 53.50±13.74, 심인성 어지럼증 군이 58.50±16.05로 심인성 어지럼증 환자군이 중추성 어지럼증 환자군에 비하여 유의하게 높은 것으로 나타났다(p<0.01). 5) 통증 증상에 있어서는 세 군간에 유의한 차이를 보이지 않았고, 위장관 증상과 성기능 장애 증상은 중추성과 말초성 어지럼증 군이 심인성 어지럼증 군에 비하여 유의하게 높은 것으로 나타났다(p<0.01). 결 론 : 상기 결과를 토대로 했을 때 어지럼증 환자들에 대한 정신과적 접근을 위하여 각 군을 나누는 것은 별 의미가 없으며 어지럼증 환자들의 어지럼증 자체에 대한 직접적이고 집중적인 치료가 더욱 필요할 것으로 생각된다. Objectives : This study was aimed to investigate psychiatric symptoms in patients with psychogenic dizziness and compare these findings with those of patients with central and peripheral dizziness. Methods : A total of 62 patients with dizziness was the subject of investigation, and patients were classified into 32 with central type, 16 with peripheral type, and 14 with psychogenic type. Korean standardized Beck Depression Inventory(K-BDI), State and Trait Anxiety Inventory(STAI), and Korean standardized edition of Symptom Checklist 90 Revised(SCL-90-R) were used for the assessment. Statistically, Pearson's chi-square test and one-way ANOVA with Scheffe's test were used with SPSS/PC for windows 6.0. Results : The results were as follows : 1) The proportion of psychogenic dizziness was 22.6% of the total subjects. 2) Total scores of K-BDI were not significantly different among the 3 groups. 3) Total scores of state anxiety and trait anxiety were not significantly different among the 3 groups. 4) In SCL-90-R, psychogenic dizziness group showed significantly higher score of phobic anxiety only(p<0.01) than central dizziness group. And others were not significantly different among the 3 groups. 5) In additional somatic symptoms, pain score was not different among the 3 groups, but gastrointestinal and sexual symptoms scores of central and peripheral dizziness group were significantly higher than those of psychogenic dizziness group(p<0.01). Conclusion : These results suggest that psychiatric symptoms in patients with psychogenic dizziness are not different from those of patients with central or peripheral dizziness. Therefore, the more direct and intensive treatment may be necessary regardless of the type of dizziness.

Cyclin-dependent kinase 4 signaling acts as a molecular switch between syngenic differentiation and neural transdifferentiation in human mesenchymal stem cells

Lee, Janet,Baek, Jeong-Hwa,Choi, Kyu-Sil,Kim, Hyun-Soo,Park, Hye-Young,Ha, Geun-Hyoung,Park, Ho,Lee, Kyo-Won,Geun Lee, Chang,Yang, Dong-Yun,Eun Moon, Hyo,Ha Paek, Sun,Lee, Chang-Woo Taylor Francis 2013 Cell Cycle Vol.12 No.3

Influence of Maternal Environmental Tobacco Smoke Exposure Assessed by Hair Nicotine Levels on Birth Weight

Lee, Jungun,Lee, Dong-Ryul,Lee, Do-Hoon,Paek, Yu-Jin,Lee, Won-Chul Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: While the perinatal outcomes of active maternal smoking are well documented, results of the effects of environmental tobacco smoke (ETS) exposure during pregnancy are inconsistent. We aimed to examine the effect of ETS exposure, assessed by maternal hair nicotine levels at $35^{th}$ week of gestation, on birth weight and the risk of small for gestational age (SGA) and low birth weight (LBW). Materials and Methods: A total of 871 non-smoking healthy pregnant women were recruited by one Korean hospital between 1 October 2006 and 31 July 2007. Hair samples were collected and anthropometric questionnaires administered at $35^{th}$ week of gestation. The primary outcome was birth weight and secondary outcomes were the risk of babies being SGA and LBW. Results: Log-transformed hair nicotine concentrations were inversely related with birth weight after adjusting for confounding variables (${\beta}=-0.077$, p=0.037). After stratifying hair nicotine levels by tertiles (T1, low [0.0-0.28 ng/mg]; T2, medium [0.29-0.62 ng/mg]; and T3, high [0.63-5.99 ng/mg]), the mean birth weight in each groups were 3,342g (T1) 3,296g (T2) and 3,290 g (T3), respectively. However the difference between groups was not statistically significant by analysis of co-variance (ANCOVA) adjusting for covariates (p=0.062). In logistic regression analysis, the risk of SGA was higher in the T3 (OR=1.59, 95%CI 1.05-2.42) than in the reference group (T1), after controlling for confounding variables. The risk of low birth weight (<2,500g, LBW) was not significantly higher (OR=1.44, 95%CI 0.95-2.19), but the risk of babies being below 3,000g birth weight was increased in the T3 group (OR=1.53, 95%CI 1.00-2.36) compared with that in the T1 group. Conclusions: Maternal ETS exposure during pregnancy was inversely related with birth weight. The risk of SGA increased in the highest ETS exposure group compared with in the low exposure group. To prevent ETS exposure during pregnancy, more comprehensive tobacco control policies are needed.

Interaction Between Carbonaceous Structure and Functionalized Single-Walled Carbon Nanotubes

Lee, Jung-Ah,Lee, Byung Chul,Lee, Sang-Myung,Paek, Kyeong-Kap,Ju, Byeong-Kwon,Lee, Yun-Hi,Shin, Hyun Joon The Electrochemical Society 2010 Journal of the Electrochemical Society Vol.157 No.6

Pb(Mg<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O₃-PbTiO₃-SrTiO₃ 세라믹의 유전 및 변위 특성에 관한 연구(Ⅱ)

이해영(H.Y. Lee),이진(J. Lee),정해덕(H.D. Jung),백영채(Y.C. Paek),이희규(H.K. Lee),이덕출(D.C. Lee) 대한전기학회 1994 대한전기학회 학술대회 논문집 Vol.1994 No.7

Efficient Security Monitoring with the Core Debug Interface in an Embedded Processor

Lee, Jinyong,Heo, Ingoo,Lee, Yongje,Paek, Yunheung Association for Computing Machinery 2016 Transactions on Design Automation of Electronic Sy Vol.22 No.1

<P>For decades, various concepts in security monitoring have been proposed. In principle, they all in common in regard to the monitoring of the execution behavior of a program (e.g., control-flow or dataflow) running on the machine to find symptoms of attacks. Among the proposed monitoring schemes, software-based ones are known for their adaptability on the commercial products, but there have been concerns that they may suffer from nonnegligible runtime overhead. On the other hand, hardware-based solutions are recognized for their high performance. However, most of them have an inherent problem in that they usually mandate drastic changes to the internal processor architecture. More recent ones have strived to minimize such modifications by employing external hardware security monitors in the system. However, these approaches intrinsically suffer from the overhead caused by communication between the host and the external monitor. Our solution also relies on external hardware for security monitoring, but unlike the others, ours tackles the communication overhead by using the core debug interface (CDI), which is readily available in most commercial processors for debugging. We build our system simply by plugging our monitoring hardware into the processor via CDI, precluding the need for altering the processor internals. To validate the effectiveness of our approach, we implement two well-known monitoring techniques on our proposed framework: dynamic information flow tracking and branch regulation. The experimental results on our FPGA prototype show that our external hardware monitors efficiently perform monitoring tasks with negligible performance overhead, mainly with thanks to the support of CDI, which helps us reduce communication costs substantially.</P>

Understanding CO2 capture mechanisms in aqueous hydrazine via combined NMR and first-principles studies

Lee, B.,Stowe, H.,Lee, K.,Hur, N.,Hwang, S. J.,Paek, E.,Hwang, G. Royal Society of Chemistry 2017 Physical chemistry chemical physics Vol.19 No.35

Characterization of Human Liver Cytochrome P-450 Enzymes Involved in the O-demethylation of a New P-glycoprotein Inhibitor HM-30181

Paek, In Bok,Kim, Sung Yeon,Kim, Maeng Sup,Kim, John,Lee, Gwansun,Lee, Hye Suk Taylor Francis 2007 Journal of toxicology and environmental health. Pa Vol.70 No.15

<P> HM-30181, 4-oxo-4H-chromene-2-carboxylic acid [2-(2-{4-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-ethyl]-phenyl}-2H-tetrazol-5-yl)-4,5-dimethoxy-phenyl]-amide, is a new P-glycoprotein inhibitor with the potential to increase the cytotoxic activity of orally coadministered paclitaxel. This study was performed to characterize human cytochrome P-450 (CYP) enzymes involved in the metabolism of HM-30181 to 4- or 5-O-desmethyl-HM-30181 (M2) and 6- or 7-O-desmethyl-HM-30181 (M3) and to investigate the inhibitory potential of HM-30181 on CYP enzymes in human liver microsomes. CYP3A4 was identified as the major isozyme responsible for the O-demethylation of HM-30181 to M2 and M3 based on the correlation analysis, chemical inhibition and immuno-inhibition study and metabolism in cDNA-expressed human CYP isozymes. HM-30181 itself had no inhibitory effects on CYPs 1A2, 2A6, 2C8, 2C9, 2C19, 2D6, and 3A4 in human liver microsomes, suggesting the possibility that the pharmacokinetics of HM-30181 could be changed with coadministration of known CYP3A4 inducers or inhibitors.</P>