Application of Support Vector Machines in Assessing Conceptual Cost Estimates

Total conceptual cost estimates and the assessment of the quality of these estimates are critical in the early stages of a building construction project. In this study, the support vector machine (SVM) model for assessing the quality of conceptual cost estimates is proposed, and the application of SVM in construction areas is investigated. The results show that the SVM model assessed the quality of conceptual cost estimates slightly more accurately than the discriminant analysis model. This shows that using the SVM has potential in construction areas. In addition, the SVM model can assist clients in their evaluation of the quality of the estimated cost and the probability of exceeding the target cost, and in their decision on whether or not it is necessary to seek a more accurate estimate in the early stages of a project.     

Piezoelectric properties in two-dimensional materials: Simulations and experiments

The piezoelectric effect, discovered in 1880 by Jacques and Pierre Curie, effectively allows to transduce signals from the mechanical domain to the electrical domain and vice versa. For this reason, piezoelectric devices are already ubiquitous, including, for instance, quartz oscillators, mechanical actuators with sub-atomic resolution and microbalances. However, the ability to synthesize two-dimensional (2D) materials may enable the fabrication of innovative devices with unprecedented performance. For instance, many materials which are not piezoelectric in their bulk form become piezoelectric when reduced to a single atomic layer; moreover, since all the atoms belong to the surface, piezoelectricity can be effectively engineered by proper surface modifications. As additional advantages, 2D materials are strong, flexible, easy to be co-integrated with conventional integrated circuits or micro-electromechanical systems and, in comparison with bulk or quasi-1D materials, easier to be simulated at the atomistic level. Here, we review the state of the art on 2D piezoelectricity, with reference to both computational predictions and experimental characterization. Because of their unique advantages, we believe 2D piezoelectric materials will substantially expand the applications of piezoelectricity.     

Measuring the economic benefits of the Youngsan River Restoration Project in Kwangju,Korea, using contingent valuation

This study examines the economic benefits of a river restoration project in the Youngsan River, Kwangju, Korea, using a contingent valuation method. It employs a spike model to address the high proportion of zero responses. The results indicate that a household's annual mean willingness to pay is KRW3410 in Kwangju and KRW1744 in other regions. The resulting benefit-cost ratio is 2.29, indicating that the project would be socially profitable, and that households appear willing to support it financially.     

Monthly Joint Operations for the Nakdong Multi-reservoir System in Korea

Abstract

This study applies a state-of-art optimization technique, SSDP/ESP (Sampling Stochastic Dynamic Programming with Ensemble Streamflow Prediction), to derive a monthly joint operating policy for the Nakdong multi-reservoir system in Korea. A rainfall-runoff model, SSARR (Streamflow Synthesis And Reservoir Regulation), is linked to the SSDP/ESP model to provide ESP scenarios for runoff during the next month in the Nakdong River basin. The primary advantage of the SSDP/ESP is that it updates the derived operating policy as new ESP forecasts become available. Another SSDP model that employs historical runoff scenarios (SSDP/Hist) is also developed. The main difference between the two SSDP models is that SSDP/Hist is an off-line model whereas the SSDP/ESP is on-line. The developed operating policies are tested with a simulation model using an object-oriented simulation software, STELLA. The simulation results show that SSDP/ESP is superior to SSDP/Hist with respect to the water supply criterion, although both models perform similarly with respect to the hydroelectric energy production criterion.     

The world’s most intense online gaming culture: Addiction and high-engagement prevalence rates among South Korean adolescents and young adults

Failure to establish agreed-upon criteria by which to measure and identify online video game addiction has resulted in a lack of reliable evidence of the actual percentage of individuals who are pathologically dependent. Building upon prior research, the present study sought to better determine the magnitude of pathological online video game play using a distinction between core and peripheral criteria for behavioral addiction. Preferences and perceptions towards online video games and addiction were also examined to better understand players’ habits. A questionnaire was administered to 1332 South Korean students across 11 high schools and 1 middle school in an area surrounding the capital of Seoul. Using a monothetic and a polythetic classification system, findings showed rates ranging between 1.7% and 25.5%, with a 2.7% addiction rate when distinguishing core from peripheral criteria. These results may suggest that online video game addiction rates in intense gaming cultures such as South Korea are not as high as otherwise believed. The findings will be of assistance to educators, policymakers, clinicians, and researchers in understanding the challenges in deriving meaningful video game addiction prevalence rates, and thus being able to better separate reality from conjecture with regard to the notion of pathological game play.     

韩国互联网内容管制

韩国政府决定通过发展ICT产业作为经济复苏的重要解决方案。近年来韩国互联网用户飞速增长，韩国政府重视互联网信息传播与国家安全、文化的健康以及下一代的教育关系，对韩国互联网内容进行管制。通过介绍韩国互联网内容管制机构、管制原则，分析韩国互联网内容管制的特点和不足。     

Comparison of national e‐health implementation in the United States and South Korea

With the development of the health care industry, there has been growing recognition that e‐health implementation is needed to improve the efficiency, quality, and safety of care. In addition, a review of previous studies suggests that much can be learned by investigating the difference in national e‐health implementation in the United States and in South Korea. To this end, the main objective of this article is to compare the national e‐health implementation in the case of the United States and South Korea. The results show that in the United States a decentralized e‐health implementation is being followed by individual‐level e‐health. South Korea is pursuing ubiquitous health (u‐health) after a hospital information system and electronic health were implemented. The United States still lags behind many other countries in the implementation of e‐health, possibly due to its low uncertainty avoidance culture. South Korea has been among the frontrunner groups in e‐health implementation as a consequence of its highly developed telecommunication infrastructures and high uncertainty avoidance culture. On the basis of these results, we recommend that establishing health care policies be done on a national scale that takes into account the countries’ cultures.     

Reliability of self-administered Work Ability Index questionnaire among Korean workers

Although the Work Ability Index (WAI) has been used in many countries, its reliability is yet to be validated in Korea. In our study, test–retest results of WAI total score, WAI category and seven subscales were compared. The correlation coefficients of WAI total score and subscales 1 and 2 between test and retest were 0.70, 0.80 and 0.63, respectively. The κ values on WAI category, subscales 4, 5, 6 and 7 were 0.52, 0.32, 0.31, 0.48 and 0.85, respectively. The results of our reliability test show that WAI scores of female, younger and private company workers were found to be higher than those of male, older and public company workers, respectively. We conclude that overall test–retest reliability of WAI in Korea is acceptable. Another notable observation from our study is that work ability dimension (subscales 1, 2 and 7) had a higher reliability, whereas health dimension (subscales 3–6) had a lower reliability.     

韩国的漆艺技法——从古代至朝鲜时代(英文)

韩国的漆艺文化已有两千年以上的悠久历史,堪称已经渗入到内房和厢房等生活文化当中的代表性艺术品。目前,韩半岛上的主要生漆生产地为北韩平安北道泰川和南韩江原道原州,占整个半岛生漆产量的大部分。韩国产生漆的品质很好,生漆的主要成分漆酚(Urushiol)的含量高,酶的活度相当好,生漆涂层的干燥时间很短,硬度也很强。但是,南韩原州产高品质生漆的产量较少,价格也比日本产的贵,因此主要依靠中国进口。从史前时代至三国时代,韩国漆艺文化的主要技法是在生漆底上施以颜色绘制纹样,统一新罗时期开始变化为在生漆底上用螺钿、琥珀、青玉、金、银等宝石材料加以装饰。其后,高丽和朝鲜时代螺钿装饰成为漆器上所采用的主要技法。高丽螺钿在中国的宋朝也得到了高度评价,其卓越性被认可,直到现在高丽螺钿也被视为韩国的代表性艺术品之一。     

A Model Korean Ubiquitous Eco-City? The Politics of Making Songdo

Building cities from scratch has continued unabated since the latter half of the twentieth century despite some of these planned cities achieving global infamy for their failures. These endeavors are, in part, due to a persistent belief by governments that newly constructed cities can set their nations on a fast path to the future. Today, challenges posed both by global climate change and increased urbanization have widened this platform from projects almost exclusively of developing nations to include those in the developed world. Today we talk of the eco-city, a local solution to a global crisis. If completion is successfully fast-tracked, the resultant eco-city will position its respective nation at the forefront of innovation in what is effectively a global race: the resultant city can be exported as a model both locally and globally. In this regard, the envisioning and building of Songdo in South Korea may not be unique. Songdo is a city underway on flat land created from wetland reclamation. As part of the Incheon Free Economic Zone (IFEZ), Songdo's development has benefited from opportunistic circumstances that has led to its pursuit of becoming a “Ubiquitous Eco-City.” The green infrastructure of the new city is to be enhanced by the provision of extra services that combine information and communication technologies as well as digital networks to ideally create harmony among the environment, society, and technology. Songdo, as planned, will position South Korea among a group of leading nations, and possibly at the forefront of new city development, potentially producing a model for export.