• Bulletin of the Korean Chemical Society
• /
• v.34 no.8
• /
• pp.2466-2472
• /
• 2013

Human immunodeficiency virus type-1 (HIV-1) is a causative agent of Acquired immunodeficiency syndrome (AIDS), which has affected a large population of the world. Viral envelope glycoprotein (gp120) is an intrinsic protein for HIV-1 to enter into human host cells. Molecular docking guided molecular dynamics (MD) simulation was performed to explore the interaction mechanism of heterobiaryl derivative with gp120. MD simulation result of inhibitor-gp120 complex demonstrated stability. Our MD simulation results are consistent with most of the previous mutational and modeling studies. Inhibitor has an interaction with the CD4 binding region. Van der Waals interaction between inhibitor and Val255, Thr257, Asn425, Met426 and Trp427 were important. This preliminary MD model could be useful in exploiting heterobiaryl-gp120 interaction in greater detail, and will likely to shed lights for further utilization in the development of more potent inhibitors.

• The Journal of Korean Society for School & Community Health Education
• /
• v.12 no.2
• /
• pp.81-96
• /
• 2011

Objectives: This study was to examine the factors affecting Stress among adolescents in an area. Methods: Data collection was conducted by self-report survey. Survey participants were 1,255 from 11 middle and 7 high school students in a county of the Chungcheongnam-do, who were selected by the cluster sampling from May 2011. The Structural Equation Modeling was employed to investigate the research Model. Results: Tobacco errands variable was found to have a negative casual effect on self-efficacy factor and male dummy variable had a significant positive casual effect on self-efficacy. Self-efficacy had a significant negative casual effect on stress, smoke dummy variable had a statistically significant negative effect on stress and friends who smoke variable were found to have a positive casual effect on stress. Conclusions: In results, it was confirmd that the adolescents experienced more study related stress than other kinds of stress. Second, it was found out that every kind of stress are relevant to emotional problems and the behaviroral problems.

• Korea journal of population studies
• /
• v.11 no.1
• /
• pp.185-196
• /
• 1988

This study considers inter-jurisdictional fiscal externalities between a central city and suburbs, rigorously examines. and empirically tests the suburban-exploitation-of-central-cities hypothesis. Using micro-migra4ion data, house-holds 'intra-metropolitan migration between 1985 and 1990 Is examined based on a random utility model. It is found that efficient population distribution between a central city and suburbs can be achieved when local government stake into account inter-jurisdictional externalities. External aids from the federal and state governments should be given to public services such as education, welfare, health, and employee retirement services, if they intend to arrest central city decline. Regional tax sharifs can be another way of dealing with these externalities.

• The Korean Journal of Archival Studies
• /
• no.1
• /
• pp.7-22
• /
• 2000

It is almost impossible to fulfill the users' information needs efficiently without any finding aids. The idiosyncrasy of archival materials had led the archivists to develop their own descriptive rules until the mid of 1980s. It was the arrival of computers and information networks that stimulated the archival community to standardize its variant descriptive practices. The primary purpose of the national and international archival description standards is to facilitate the cooperative archival data exchange. The Ad Hoc Commission on Descriptive Standards of the International Council on Archives adopted ISAD(G) and ISAAR(CPF) in 1993 and in 1995 respectively. ISAD(G) guides the formulation of information in each of 26 elements that may be combined to constitute the description of an archival entity. ISAAR(CPF) is to give general rules for the establishment of archival authority records in descriptions of archival documents. Histories, structures and fundamental principles of those two international archival standards have been studies in this article. Most of the present archival description standards are based on the principle of provenance and the authority model. The instability of modern organizations and the digitalization of record keeping systems have been making the archivists to review these basic archival principles. It is suggested that Korean archival community should attempt to draft a national archival descriptive standard suitable to the Korean archival practice and Korean language in the framework of the international standards.

• Steel and Composite Structures
• /
• v.32 no.4
• /
• pp.423-441
• /
• 2019

This study aims to accurately predict the first ply failure loads of laminated composite hypar shell roofs with different boundary conditions. The geometrically nonlinear finite element method (FEM) is used to analyse different symmetric and anti-symmetric, cross and angle ply shells. The first ply failure loads are obtained through different well-established failure criteria including Puck's criterion along with the serviceability criterion of deflection. The close agreement of the published and present results for different validation problems proves the correctness of the finite element model used in the present study. The effects of edge conditions on first ply failure behavior are discussed critically from practical engineering point of view. Factor of safety values and failure zones are also reported to suggest design and non-destructive monitoring guidelines to practicing engineers. Apart from these, the present study indicates the rank wise relative performances of different shell options. The study establishes that the angle ply laminates in general perform better than the cross ply ones. Among the stacking sequences considered here, three layered symmetric angle ply laminates offer the highest first ply failure load. The probable failure zones on the different shell surfaces, identified in this paper, are the areas where non-destructive health monitoring may be restricted to. The contributions made through this paper are expected to serve as important design aids to engineers engaged in composite hypar shell design and construction.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.10
• /
• pp.189-200
• /
• 2022

The gig economy offers many advantages, such as flexibility, variety, independence, and lower cost. However, there are also safety concerns, lack of regulations, uncertainty, and unsatisfactory services, causing people to voice their opinion on social media. This paper aims to explore the sentiments of consumers concerning gig economy services (Grab, Foodpanda and Airbnb) through the analysis of social media. First, Vader Lexicon was used to classify the comments into positive, negative, and neutral sentiments. Then, the comments were further classified into three machine learning algorithms: Support Vector Machine, Light Gradient Boosted Machine, and Logistic Regression. Results suggested that gig economy services in Malaysia received more positive sentiments (52%) than negative sentiments (19%) and neutral sentiments (29%). Based on the three algorithms used in this research, LGBM has been the best model with the highest accuracy of 85%, while SVM has 84% and LR 82%. The results of this study proved the power of text mining and sentiment analysis in extracting business value and providing insight to businesses. Additionally, it aids gig managers and service providers in understanding clients' sentiments about their goods and services and making necessary adjustments to optimize satisfaction.

• Korea Trade Review
• /
• v.44 no.2
• /
• pp.287-305
• /
• 2019

The export of agricultural, fisheries, and food products acts as an engine of growth for developing countries in particular. However, exporting these items is easier said than done since issues of certification and inspection, so-called technical barriers to trade (TBT) and sanitary and phytosanitary measures (SPS), in developed markets have worked as major obstacles for exports. This paper examines the institutional aspects and recent trends of South Korea's TBT/SPS-related cases against exporting firms of the developing countries. We suggest a win-win partnership model that can promote cooperative synergies between Korea and developing employing trade-related technical cooperation or ODA (Official Development Aid). Technical cooperation such as the provision of on-spot field consulting services on TBT/SPS-related issues for exporting firms and Korean OEM firms of developing countries can lead to mutual gains. This cooperative partnership can create gains from "the trade-development nexus" for both sides while promoting sustainable trade and investment relationships between Korea and developing countries.

• International Area Studies Review
• /
• v.20 no.4
• /
• pp.23-36
• /
• 2016

This studies the relationship between ODA and export performance of donor countries in Myanmar. This study analyzes 19 donor countries from 2002 to 2014 by using gravity model. The results show that ODA improves the export performance of donor countries in Myanmar in the period. The larger the amount of ODA, the larger the exports in Myanmar. And the rate of increase of ODA is also important in determining the export performance. These imply that ODA increases donor's export directly as well as indirectly by improving the relationship between donors and receivers. These results are important for Korea that is increasing ODA into Myanmar. Korea should search for a mode of ODA supporting as well as the amount of ODA.

• Journal of Korea Multimedia Society
• /
• v.24 no.2
• /
• pp.295-304
• /
• 2021

Learning assistance system that continuously measures user's concentration will be helpful to grasp the concentration pattern and adjust the learning method accordingly to improve the learning efficiency. Although a lot of various learning aids have been proposed, there have been few studies on the concentration monitoring system in real time. Therefore, in this study, we developed an Android-based mobile application that can measure concentration during study by using functional near-infrared spectroscopy, which is used to measure brain activity. First, the task accuracy was predicted at a maximum level of 93.75% from the prefrontal oxygenation characteristics measured while performing the visual Q&A task on 11 college students, and a concentration calculation formula based on a linear regression model was derived. Then, a survey on the usability of the mobile application was conducted, overall high satisfaction and positive opinions were obtained. From these findings, this application can be used as a customized learning aid application for users, and further, it can help educators improve the quality of classes based on the level of concentration of learners.

• International Journal of Computer Science & Network Security
• /
• v.22 no.4
• /
• pp.17-26
• /
• 2022

Sensor Nodes play a major role to monitor and sense the variations in physical space in various real-time application scenarios. These nodes are powered by limited battery resources and replacing those resource is highly tedious task along with this it increases implementation cost. Thus, maintaining a good network lifespan is amongst the utmost important challenge in this field of WSN. Currently, energy efficient routing techniques are considered as promising solution to prolong the network lifespan where multi-hop communications are performed by identifying the most energy efficient path. However, the existing scheme suffer from performance related issues. To solve the issues of existing techniques, a novel hybrid technique by merging particle swarm optimization and game theory model is presented. The PSO helps to obtain the efficient number of cluster and Cluster Head selection whereas game theory aids in finding the best optimized path from source to destination by utilizing a path selection probability approach. This probability is obtained by using conditional probability to compute payoff for agents. When compared to current strategies, the experimental study demonstrates that the proposed GTPSO strategy outperforms them.