Intertemporal Behavior of Expected Market Returns : Time-Varying and Asymmetry Properties

Kiseok Nam,Chong Soo Pyun,Joshua Krausz 한국재무학회 2008 한국재무학회 학술대회 Vol.2008 No.05

The intertemporal behavior of expected market returns is not only driven by predictable market volatility, but also by unexpected volatility changes. Most of the empirical literature ignores the effects of unexpected volatility changes on the intertemporal relation; consequently, the previous empirical results suffer from the omitted variable bias. With the effects of a volatility shock incorporated in the estimation, we find a strong positive intertemporal relation. We also find that the quicker reversion of a negative return is attributable to a negative intertemporal relation. We interpret this negative intertemporal relation under a negative return shock as a reflection of strong optimistic expectations by investors on the future performance of stock prices.

Comparative Analysis of the Serratus Anterior Muscle Activity When Right and Left Knee Lift during Quadruped Position on Push Up Plus

Nam, KiSeok,Kim, JiWoong,Park, JiWon 대한물리치료학회 2020 대한물리치료학회지 Vol.32 No.1

Purpose: This study examined the effects of the right or left knee lift during push up plus in the quadruped position on the serratus anterior (SA) muscle activity. Methods: Twenty-one subjects (male 11, female 10) performed the quadruped position on push up plus. The muscle activities of the lower trapezius (LT), SA, and upper trapezius (UT) were measured by surface electromyography. Repeated measurements of one-way ANOVA were performed for statistical analysis of the data, and the criterion for statistical significance was set to p<0.05 and comparative analysis of the UT and SA ratio using a Paired t-test. Results: The right SA increased the muscle activity of the right knee lift during quadruped position push up plus (p<0.05). In particular, the right SA muscle activity was higher than the left. In addition, comparative analysis of the UT and SA ratio to the right knee lift during quadruped position push up plus was performed (p<0.05). The right was found to be a significant statistic compared to the left, but the left SA increased the muscle activity of the left knee lift during quadruped position push up plus (p<0.05). The left SA muscle activity was higher than right. In addition, comparative analysis of UT and SA ratio to the left knee lift during quadruped position push up plus was performed (p<0.05). The left was found to be a significance statistic than the right. In addition, the interaction effect between the groups showed significant differences (p<0.05). Conclusion: Knee lift during push up plus is recommended for the selective activation of a research exercise protocol of one side of the serratus anterior.

Comparative Analysis of the Serratus Anterior Muscle Activity When Right and Left Knee Lift during Quadruped Position on Push Up Plus

( Kiseok Nam ),( Jiwoong Kim ),( Jiwon Park ) 대한물리치료학회 2020 대한물리치료학회지 Vol.32 No.1

Purpose: This study examined the effects of the right or left knee lift during push up plus in the quadruped position on the serratus anterior (SA) muscle activity. Methods: Twenty-one subjects (male 11, female 10) performed the quadruped position on push up plus. The muscle activities of the lower trapezius (LT), SA, and upper trapezius (UT) were measured by surface electromyography. Repeated measurements of one-way ANOVA were performed for statistical analysis of the data, and the criterion for statistical significance was set to p<0.05 and comparative analysis of the UT and SA ratio using a Paired t-test. Results: The right SA increased the muscle activity of the right knee lift during quadruped position push up plus (p<0.05). In particular, the right SA muscle activity was higher than the left. In addition, comparative analysis of the UT and SA ratio to the right knee lift during quadruped position push up plus was performed (p<0.05). The right was found to be a significant statistic compared to the left, but the left SA increased the muscle activity of the left knee lift during quadruped position push up plus (p<0.05). The left SA muscle activity was higher than right. In addition, comparative analysis of UT and SA ratio to the left knee lift during quadruped position push up plus was performed (p<0.05). The left was found to be a significance statistic than the right. In addition, the interaction effect between the groups showed significant differences (p<0.05). Conclusion: Knee lift during push up plus is recommended for the selective activation of a research exercise protocol of one side of the serratus anterior.

지식관리시스템 연계를 위한 미들웨어 기반 다중 전송 서비스

남덕윤(Dukyun Nam),김평(Pyung Kim),최기석(KiSeok Choi),이동만(Dongman Lee) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.1

지식관리시스템은 기관 및 회사들에서 자신들의 조직에 맞는 시스템으로 구축하여 기사용하고 있다. 조직별 지식관리시스템에서는 하나의 조직에서 발생할 수 있는 지식만을 축적하고 있다. 최근 지식 고도화 및 혁신사업의 하나인 ‘지식관리’를 위해 다른 조직의 지식관리시스템과의 연계를 통한 지식 공유 및 기존 지식들에서 양질의 지식을 창출할 수 있는 체계적 지식관리시스템 구축에 주안점을 두고 있다. 본 논문에서는 별도로 개발된 다수의 지식관리시스템 사이의 연계를 위한 통신 방식을 살펴보고, 시스템 구축의 편의를 도모할 수 있는 미들웨어인 CORBA와 Java Message Service (JMS)를 활용한 메시지 다중 전송 서비스 연계방식을 제안한다.

Granulocyte Colony Stimulating Factor Ameliorate Hepatic Apoptosis in Non-alcoholic Fatty Liver Disease via PI3K and AKT Activation: Beyond Marrow Stem Cell Mobilization

( Ho Hyun Nam ),( Dae Won Jun ),( Kiseok Jang ),( Joo Hyun Sohn ),( Jae Yoon Jeong ),( Chang Hong Lee ),( Waqar Khalid Saeed ),( Jai Sun Lee ),( Hyeon Tae Kang ),( Yeon Ji Chae ) 대한간학회 2016 춘·추계 학술대회 (KASL) Vol.2016 No.1

Aims: Protective effects of granulocyte colony stimulating factor (G-CSF) on nonalcoholic fatty liver disease (NAFLD) have been reported in animal models. However, the therapeutic effect of G-CSF has been suggested via marrow stem cell mobilization. We investigated the direct effect of G-CSF on hepatocytes in NAFLD. Methods: G-CSFr expression was evaluated in various liver disease model (NAFLD, alcoholic hepatitis, toxic hepatitis, chronic liver disease model). Two kinds of NAFLD models (high fat (HF), methionine choline deficient (MCD)) were used. In HF model included five arms as follows: control, HF, and three HF+G-CSF (30μg/kg, i.p) treatment groups (G1, G-CSF once weekly from 8th~12th week; G2, once daily for 5 days only in 9th week; G3, twice weekly from 9th to 12th week). In MCD model, four groups were included as follows; control, MCD, short and long acting G-CSF were tested. Long acting G-CSG was injected once a month. For in vitro experiments, the HepG2 cells were treated with palmitic acid (PA) 400μM, oleic acid (OA) 800μM, and G-CSF 100ng/ml. Cell viability (MTT) and oxidative stress (ROS), G-CSF receptor (IF, RT-PCR) were also measured. Results: The G-CSFr expression increased significantly in HF (14.7 times), alcohol hepatitis (7.1 times), chronic thioacetamide (TAA) (2.4 times), and ischemia reperfusion (IR) (6.8 times) groups as compared to the control. In HF induced NAFLD model, G-CSF treatment did not decrease the body weight compared to control groups. Continuous low dose group which can’t mobilize marrow stem cell (G3 group) showed significantly reduced intrahepatic fat accumulation as well as liver chemistry compare to HF induced NAFLD model without changing of body weight and liver to body weight ratio. Low dose long acting G-CSF with once a month injection also improved intrahepatic fat amount as well as degree of intrahepatic inflammation. Low dose long acting G-CSF treatment reduced the mRNA expression for hepatic de novo triglycerides synthesis (SREBP1c, FAS, SCD-1), cholesterol synthesis (SREBP2, HMG-CoA reductase) and inflammatory markers (MCP-1 TNF-a). G-CSF treatment increased cell proliferation markers (p-PI3 kinase, p-Akt), while decreased apoptosis in MCD diet groups. In Vitro results as follows; G-CSF+PA treatment increased cell viability in both 24h, and 48h treated groups. ROS was also significantly reduced in G-CSF group. Cell viability increased G-CSF group but decreased in G-CSF+PI3 kinase inhibitor and PI3 kinase inhibitor alone groups. Similarly, ROS decreased G-CSF but increased in G-CSF+PI3 kinase inhibitor and PI3 kinase inhibitor alone groups. Conclusions: G-CSF receptor expression in Hepatocytes in various NAFLD model and G-CSF administration of low-density low-frequency improves HF model and long acting G-CSF improves MCD model.

Design and Development of protecting personal information system in PDF electronic documents

Cheol-Joo Chae,Kwang-Nam Choi,YongJu Shin,Kiseok Choi,Jae-Soo Kim 중소기업융합학회 2015 중소기업융합학회 국제학술대회논문집 Vol.2 No.1

The case where the electronic document in which the personal information is included is shared in Internet. To prevent this problem, in the case of the existing electronic document personal information technology, the focus is adjusted of the containment of the electronic document in which the personal information is included. However, in the case of this electronic document personal information protection technology, there is the weakness that it is difficult to share the information on the information-oriented age. Therefore, in this paper, the method that it detects the personal information included in the electronic document and it masks and there is no outflow of the personal information, the electronic document can be shared are proposed.

The electronic document retrieval system development of the XML based

Cheol-Joo Chae,Kwang-Nam Choi,YongJu Shin,Kiseok Choi,Jae-Soo Kim 중소기업융합학회 2015 중소기업융합학회 국제학술대회논문집 Vol.2 No.1

자동 추출된 시간정보를 이용한 사건 클러스터링

김평(Pyung Kim),남덕윤(Dukyun Nam),최기석(KiSeok Choi),맹성현(SungHyun Myaeng) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.1

신문기사를 대상으로 사건 단위로 문서를 클러스터링 하기 위해서, 기존의 연구에서는 기사의 발행일 또는 기사의 내용만 사용하여 하나의 사건을 다른 사건과 구분하는 방법을 사용해 오고 있다. 하지만 사건의 전개가 시간 차이를 두고 진행되는 경우 또는 비슷한 시간대에 같은 범주에 속하는 사건이 발생하는 경우 기사의 발행일만 사용하여 사건 관련 기사를 구분하는 것은 한계가 있다. 본 연구에서는 한국어 신문기사를 대상으로 신문기사에 나타난 시간정보를 자동 추출하고, 이를 기사의 발행일을 기준으로 정규화 한 후 사용하여 사건 단위로 기사를 클러스터링 하는 방법을 개발하였다. 즉 한국어 신문 기사를 대상으로 기사에 나타난 시간 표현을 자동으로 추출한 후, 사건과의 유사도 비교에 사용함으로써 사건 단위 클러스터링의 정확도를 높이기 위한 방법을 제안한다.

Effect of Neurodynamics on Pain and Paresthesia in Post-operated Patients with Lumbar Disc Herniation

( Ki-ryong Jang ),( Ji-won Park ),( Kiseok Nam ) 대한물리치료학회 2020 대한물리치료학회지 Vol.32 No.2

Purpose: Some patients who have undergone surgery due to lumbar disc herniation still complain of leg pain and other abnormal sensations. Therefore, the study examined the effects of the neurodynamics on pain and other abnormal nerve sensations in post-operated patients with lumbar disc herniation. Methods: The participants of this study comprised 20 adults (10 males and 10 females) who were diagnosed with lumbar disc herniation. The subjects were classified into two groups of 10 patients each in the lower extremity neurodynamics (LEN) and lumbar stabilization exercise (LSE) groups. Each intervention was applied twice a day for one week and was composed of two different exercise patterns; one was applied by a therapist, and the other was performed by the patients themselves. The data were analyzed using assessment methods of Digital Infrared Thermal Imaging (DITI), Toronto clinical neuropathy scoring system (TCNSS), Sympathetic Skin Response (SSR) test, and Oswestry Disability Index (ODI) scale. Results: Significant differences in TCNSS, DITI, ODI scale were observed between the LEN and LSE group (p<0.01). On the other hand, there was no significant difference in the SSR test between pre and post-treatment (p>0.05). Conclusion: The results indicated that neurodynamics treatment is effective in pain reduction and abnormal sensations, such as leg muscle cramps, in post-operated patients with lumbar disc herniation.

OAuth 2.0 프로토콜에서 E-mail을 이용한 사용자 권한 인증

채철주 ( Cheol-joo Chae ),최광남 ( Kwang-nam Choi ),최기석 ( Kiseok Choi ),예용희 ( Yong-hee Yae ),신용주 ( Younju Shin ) 한국인터넷정보학회 2015 인터넷정보학회논문지 Vol.16 No.1

최근 다양한 웹 서비스와 어플리케이션들이 사용자에게 제공되고 있다. 이러한 서비스들은 인증된 사용자에 한해서 서비스를 제공하기 때문에 사용자는 매번 서비스 별로 인증을 수행해야 하는 불편함을 겪고 있다. 이러한 불편함을 해결하기 위해 3^rd Party 어플리케이션이 웹 서비스에 대하여 제한된 접근 권한을 얻을 수 있게 해주는 OAuth(Open Authorization) 프로토콜이 등장하게 되었다. 이러한 OAuth 프로토콜은 사용자에게 편리하고 유연한 서비스를 제공한다. 그러나 OAuth 2.0 프로토콜에서는 재전송 공격, 피싱 공격, 위장 공격 취약점이 발생할 수 있다. 그러므로 본 논문에서는 OAuth 2.0 프로토콜의 보안성 향상을 위하여 E-mail인증을 통해 Resource Owner를 인증 후 Access Token 발급을 할 수 있는 방법을 제안한다. Currently there are wide variety of web services and applications available for users. Such services restrict access to only authorized users, and therefore its users often need to go through the inconvenience of getting an authentication from each service every time. To resolve of such inconvenience, a third party application with OAuth(Open Authorization) protocol that can provide restricted access to different web services has appeared. OAuth protocol provides applicable and flexible services to its users, but is exposed to reply attack, phishing attack, impersonation attack. Therefore we propose method that after authentication Access Token can be issued by using the E-mail authentication. In proposed method, regular user authentication success rate is high when value is 5 minutes. However, in the case of the attacker, the probability which can be gotten certificated is not more than the user contrast 0.3% within 5 minutes.