• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.485-496
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• 2013

In recent years, frequent terror or military attacks by explosion or impact accidents have occurred. Examplary case of these attacks were World Trade Center collapse and US Department of Defense Pentagon attack on Sept. 11 of 2001. These attacks of the civil infrastructure have induced numerous casualties and property damage, which raised public concerns and anxiety of potential terrorist attacks. However, a existing design procedure for civil infrastructures do not consider a protective design for extreme loading scenario. Also, the extreme loading researches of prestressed concrete (PSC) member, which widely used for nuclear containment vessel, gas tank, bridges, and tunnel, are insufficient due to experimental limitations of loading characteristics. To protect concrete structures against extreme loading such as explosion and impact with high strain rate, understanding of the effect, characteristic, and propagation mechanism of extreme loadings on structures is needed. Therefore, in this paper, to evaluate the impact resistance capacity and its protective performance of bi-directional unbonded prestressed concrete member, impact tests were carried out on $1400mm{\times}1000mm{\times}300mm$ for reinforced concrete (RC), prestressed concrete without rebar (PS), prestressed concrete with rebar (PSR, general PSC) specimens. According to test site conditions, impact tests were performed with 14 kN impactor with drop height of 10 m, 5 m, 4 m for preliminary tests and 3.5 m for main tests. Also, in this study, the procedure, layout, and measurement system of impact tests were established. The impact resistance capacity was measured using crack patterns, damage rates, measuring value such as displacement, acceleration, and residual structural strength. The results can be used as basic research references for related research areas, which include protective design and impact numerical simulation under impact loading.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.91-104
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• 2023

The records system is believed to have started in Italy in the 14th century in line with trade developments in Europe. In 1491, Luca Pacioli, a mathematician, and an Italian Franciscan monk wrote the first book that described double-entry accounting processes. In many countries, including Korea, the government accounting standards used single-entry bookkeeping rather than double-entry bookkeeping that can be aggregated by account subject. The cash-based and single-entry bookkeeping used by the government in the past had limitations in providing clear information on financial status and establishing a performance-oriented financial management system. Accordingly, the National Accounting Act (promulgated in October 2007) stipulated the introduction of double-entry bookkeeping and accrual accounting systems in the government sector from January 1, 2009. Furthermore, the Korean government has also introduced International Financial Reporting Standards (IFRS), and the System of National Accounts (SNA). Since 2014, Korea owned five national accounts. In Korea, valuation began with the 1968 National Wealth Statistics Survey. The academic origins of the valuation of national wealth statistics which had been investigated by due diligence every 10 years since 1968 are based on the 'Engineering Valuation' of professor Marston in the Department of Industrial Engineering at Iowa State University in the 1930s. This field has spread to economics, etc. In economics, it became the basis of capital stock estimation for positive economics such as econometrics. The valuation by the National Wealth Statistics Survey contributed greatly to converting the book value of accounting data into vintage data. And in 2000 National Statistical Office collected actual disposal data for the 1-digit asset class and obtained the ASL(average service life) by Iowa curve. Then, with the data on fixed capital formation centered on the National B/S Team of the Bank of Korea, the national wealth statistics were prepared by the Permanent Inventory Method(PIM). The asset classification was also classified into 59 types, including 2 types of residential buildings, 4 types of non-residential buildings, 14 types of structures, 9 types of transportation equipment, 28 types of machinery, and 2 types of intangible fixed assets. Tables of useful lives of tangible fixed assets published by the Korea Appraisal Board in 1999 and 2013 were made by the Iowa curve method. In Korea, the Iowa curve method has been adopted as a method of ASL estimation. There are three types of the Iowa curve method. The retirement rate method of the three types is the best because it is based on the collection and compilation of the data of all properties in service during a period of recent years, both properties retired and that are still in service. We hope the retirement rate method instead of the individual unit method is used in the estimation of ASL. Recently Korean government's accounting system has been developed. When revenue expenditure and capital expenditure were mixed in the past single-entry bookkeeping we would like to suggest that BOK and National Statistical Office have accumulated knowledge of a rational difference between revenue expenditure and capital expenditure. In particular, it is important when it is estimated capital stock by PIM. Korea also needs an empirical study on economic depreciation like Hulten & Wykoff Catalog A of the US BEA.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.77-97
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• 2010

Market timing is an investment strategy which is used for obtaining excessive return from financial market. In general, detection of market timing means determining when to buy and sell to get excess return from trading. In many market timing systems, trading rules have been used as an engine to generate signals for trade. On the other hand, some researchers proposed the rough set analysis as a proper tool for market timing because it does not generate a signal for trade when the pattern of the market is uncertain by using the control function. The data for the rough set analysis should be discretized of numeric value because the rough set only accepts categorical data for analysis. Discretization searches for proper "cuts" for numeric data that determine intervals. All values that lie within each interval are transformed into same value. In general, there are four methods for data discretization in rough set analysis including equal frequency scaling, expert's knowledge-based discretization, minimum entropy scaling, and na$\ddot{i}$ve and Boolean reasoning-based discretization. Equal frequency scaling fixes a number of intervals and examines the histogram of each variable, then determines cuts so that approximately the same number of samples fall into each of the intervals. Expert's knowledge-based discretization determines cuts according to knowledge of domain experts through literature review or interview with experts. Minimum entropy scaling implements the algorithm based on recursively partitioning the value set of each variable so that a local measure of entropy is optimized. Na$\ddot{i}$ve and Booleanreasoning-based discretization searches categorical values by using Na$\ddot{i}$ve scaling the data, then finds the optimized dicretization thresholds through Boolean reasoning. Although the rough set analysis is promising for market timing, there is little research on the impact of the various data discretization methods on performance from trading using the rough set analysis. In this study, we compare stock market timing models using rough set analysis with various data discretization methods. The research data used in this study are the KOSPI 200 from May 1996 to October 1998. KOSPI 200 is the underlying index of the KOSPI 200 futures which is the first derivative instrument in the Korean stock market. The KOSPI 200 is a market value weighted index which consists of 200 stocks selected by criteria on liquidity and their status in corresponding industry including manufacturing, construction, communication, electricity and gas, distribution and services, and financing. The total number of samples is 660 trading days. In addition, this study uses popular technical indicators as independent variables. The experimental results show that the most profitable method for the training sample is the na$\ddot{i}$ve and Boolean reasoning but the expert's knowledge-based discretization is the most profitable method for the validation sample. In addition, the expert's knowledge-based discretization produced robust performance for both of training and validation sample. We also compared rough set analysis and decision tree. This study experimented C4.5 for the comparison purpose. The results show that rough set analysis with expert's knowledge-based discretization produced more profitable rules than C4.5.

• Journal of the Korean Home Economics Association
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• v.27 no.2
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• pp.163-185
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• 1989

Korean home economics education has around 100 years history. The main aims of home economics education up 1950 had not been changed, they were mainly for the improvement of household-skill to raise both standard of living and life quality as well as womanhood. After 1960's the standard of living drastically improved and the industrialization of Korean society was quite rapidly proceeded from simple to complex one. Because of these changes, I considered that the aims and the contents of home economics education should be reexamined and reshaped. This study motivated me that especially home economics major should be trained to be competent enough to work in industrialized society as much as the input to her college education. As industialization was made progress, family member's diverse role differentiation also occurred from past simple role such as house wife or girl's high school teacher among by home economics major. In this current societal change, most of the home economics major have wish to have opportunities obtaining new kinds of employment rather than obtaining merely teaching work. With this in mind I made a study on college level home economics education of the new adjustment to current and future industrialized Korean society. (1) The full number of officially admissible home economics major in 169 Korean colleges, 70 junior colleges, and one open university were as follows, 7139, 6080, and 230 respectively. The percentages of employed of employed numbers of them for the college and junior college graduates were 26.5 and 39.0 respectively. (2) The certificate qualifications issued to college home economics major are nutritionist (1st grade and 2nd grade), clothes and textilist, home economics teacher (2nd grade for high school) and kindergartener (2nd grade), The qualifications are certified after majoring each field from major departments of college of home economics by Ministrys of Labour and Education of the Korean government. The percentages of their employment are low as mentioned earlier. (3) To find out new employment opportunity for home economics graduates in home economist in business (henceforce/HEIB) status quo of consumer division for mational enterprise was surveyed. According to govermment decree of general law of consumer protection (1980), enterprise should organize bureau (offics, subdivision) on liability to consumer's complaint. Of 89.6% of the enterprise established th subdivision in which 96.2% of employee was male (3.8% was female). Of the employee college graduate and high school graduate were 93.2% and 6.8% respectively. On the employee's major acadmic backgroud (%), economics and business administration, engineering and low-political science were 39.5, 26.2 and 11.2 respectively. (4) To study on the relation between home economics and home economist in business, the aspect of historical development of HEIB, group of HEIB employing enterprise and their nature of business were tried to find out as well as perception and evaluation by enterprise on HEIB. (a) In the united States of America employed home economics major to enterprise was organized autonomously HEIB subdivision within American Home Economics Association since 1920's and the membership of HEIB was 3,000 of the AHEA membership 50,000. (b) In Japan the Japanese founder HEIB had three times the bilateral congress with the U.S.HEIB and had 10th anniversary celebration in 1988. Japanese HEIB member are not necessary to be home economics graduates but should have certificate as consumer adviser effected by the Minister of Trade and Industry. Japanese subdivision of consumer affaire within Japanese enterprise employ the consumer adviser with the certificate. Because of this different system from the United Sates, Japanese HEIB call their title "HEEB" instead of HEIB. The Japanese consumer adviser certificate system had initiated since 1980 and it belongs to 2nd level national qualification certificate. Currently active membership of Japanese "HEEB" association had increased from 115 (in 1979) to 319 in 1988. (5) For the opening of the future new employment of home economics graduates to enterprise and qualification required for the HEIB by national enterprise in Korea, I studied on the courses which seem to be important and required by employee in the field of HEEB in the United States of America and preliminary curriculum for home economics related major student aimning to be the future "HEEB" by Japanese HEEB study group of Japanese Association of Home Economics. It is suggested that it is very important and urgent to realize as home economics educator to have common deep concern and endeavors on opening new employment for our home economics major student1), we should try to publicize strongly and let enterprise and consumer protection board realize that employee in the subdivision of consumer protection should be the one who well experienced home economics major graduates2), we, home economics educator, should try to develop actively new curriculum in line of the suggestion made earlier for our future home economics major student of open broadly their future employment opportunities3), we, home economics educators, should try to have consensus on whether we should have support from government in terms of receiving national qualification certificate on consumer pretection or not4), and I would appreciate if the Korean Home Economics Association and Korean Home Management Society paydeep and positive concern on this matter.

• Safety and Health at Work
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• v.7 no.4
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• pp.372-380
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• 2016

Background: The aim of this study was to estimate the number of workers exposed to diesel engine exhaust (DEE) by industry and year in the Republic of Korea. Method: The estimates of workers potentially exposed to DEE in the Republic of Korea were calculated by industry on the basis of the carcinogen exposure (CAREX) surveillance system. The data on the labor force employed in DEE exposure industries were obtained from the Census on Establishments conducted by the Korea National Statistical Office from 1993 to 2013. The mean values of prevalence rates adopted by EU15 countries were used as the primary exposure prevalence rates. We also investigated the exposure prevalence rates and exposure characteristics of DEE in 359 workplaces representing 11 industries. Results: The total number of workers exposed to DEE were estimated as 270,014 in 1993 and 417,034 in 2013 (2.2% of the total labor force). As of 2013, the industry categorized as "Land transport" showed the highest number of workers exposed to DEE with 174,359, followed by "Personal and household services" with 70,298, "Construction" with 45,555, "Wholesale and retail trade and restaurants and hotels" with 44,005, and "Sanitation and similar services" with 12,584. These five industries, with more than 10,000 workers exposed to DEE, accounted for 83% of the total DEE-exposed workers. Comparing primary prevalence rates used for preliminary estimation among 49 industries, "Metal ore mining" had the highest rate at 52.6%, followed by "Other mining" with 50.0%, and "Land transport" with 23.6%. Conclusion: The DEE prevalence rates we surveyed (1.3-19.8%) were higher than the primary prevalence rates. The most common emission sources of DEE were diesel engine vehicles such as forklifts, trucks, and vans. Our estimated numbers of workers exposed to DEE can be used to identify industries with workers requiring protection from potential exposure to DEE in the Republic of Korea.

• Membrane Journal
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• v.28 no.1
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• pp.75-82
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• 2018

Forward osmosis (FO) desalination system has been highlighted to improve the energy efficiency and drive down the carbon footprint of current reverse osmosis (RO) desalination technology. To improve the trade-off between water flux and salt rejection of thin film composite (TFC) desalination membrane, thin film nanocomposite membranes (TFN), in which nanomaterials as a filler are embeded within a polymeric matrix, are being explored to tailor the separation performance and add new functionality to membranes for water purification applications. The objective of this article is to develop a graphene nanocomposite membrane with high performance of water selective permeability (high water flux, high salt rejection, and low reverse solute diffusion) as a next-generation FO desalination membrane. For advances in fabrication of graphene oxide (GO) membranes, layer-by-layer (LBL) technique was used to control the desirable structure, alignment, and chemical functionality that can lead to ultrahigh-permeability membranes due to highly selective transport of water molecules. In this study, the GO nanocomposite membrane fabricated by LBL dip coating method showed high water flux ($J_w/{\Delta}{\pi}=2.51LMH/bar$), water selectivity ($J_w/J_s=8.3L/g$), and salt rejection (99.5%) as well as high stability in aqueous solution and under FO operation condition.

• Korean Journal of Oriental Medicine
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• v.18 no.2
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• pp.1-16
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• 2012

Objectives : The 10th Conference of the Parties to the Convention on Biological Diversity (COP 10) was held in Nagoya, Japan in October 2010, during which an international convention on access to genetic resources and conventional knowledge and sharing of benefits thereof was adopted. The Oriental Medicine field uses medicinal herbs based on genetic resources, as well as traditional knowledge about genetic resources. As such, if Korea, China and Japan compete over the ownership of such traditional knowledge, it will almost certainly trigger disputes over the payment of royalties among other problems. Notably, since the traditional medicine industry is closely related with China, it is highly likely this will adversely affect Korea's production of medicines using natural materials, including Korean herbal doctors' prescription, formulation and preparation of medicinal herbs. Methods : This study also analyzed the recent situation in Japan, which is the chair nation of the Nagoya Protocol and a member nation like Korea. It analyzed the Japanese people's awareness of the Nagoya Protocol and its strategies in the two years since its adoption, as well as the Guidelines for Genetic Resources, which were newly revised in 2012. Conclusions : The Nagoya Protocol requires the preparation of legislative and administrative measures and policies in order to pave the way for sharing the benefits deriving from the use of genetic resources and the relevant traditional knowledge with the providers of such resources. Thus, corresponding domestic legal measures need to be taken. Such measures include the refining of the procedure of accessing genetic resources, the designation of liaison offices, a competent agency and a supervisory agency, and the building of a system designed to issue internationally acknowledged certificates. It is also important to operate related professional consulting offices, as is the case in Japan. In addition, in the case of genetic resources, there is a need to seek multinational and bilateral cooperation including free trade agreements. Regarding traditional knowledge about genetic resources, measures need to be prepared to enable the three East Asian countries, namely, Korea, China and Japan, to commonly use ancient literature on Oriental medicine and to claim exclusive rights to such intellectual properties. Notably, with China now moving to expand the scope of traditional knowledge through the WIPO, Korea needs to prepare response measures.

• Journal of Korea Technology Innovation Society
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• v.19 no.3
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• pp.439-464
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• 2016

The technical regulation and conformity assessment procedure of our country on ICT equipments is currently required to have more innovation due to the request of main trade countries, the second phase conclusion of MRA, necessity of expansion of conformity assessment service market and demand of manufacturers. The world's leading advanced countries have already proceeded with innovation based on privatization plan. According to the comparative analysis of the level, it turned out that Japan obtained the highest level of privatization while South Korea ranked the lowest level. According to the research result of examination and certification ability of private institutions of our country, it turned out that our country is expected to have possibility of achieving higher level of privatization than that of the present. Moreover, according to the questionnaire survey conducted to the persons concerned regarding privatization direction, they gave positive response to all the indicated survey contents of privatization direction in terms of "delegation of certification services to private sectors (contracting-out)", "transformation of EMC into private voluntary standard" and "changeover of conformity assessment agent". However, from the view of acceptance and conflict model, it is estimated that starting from "delegation of certification services to private sectors (contracting-out)" seems to be the most advisable plan. Also, prior to privatization, it is required to improve relevant systems such as certification examiner system.

• Journal of Distribution Science
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• v.4 no.1
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• pp.53-78
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• 2006

We call this world network society. Logistics is one of important network systems which connect people, materials and information. The World Economy Conditions of 21st Century has been Changed so rapidly. These Changes are more conspicuous in Northeast Asia than other Regions. China, North Korea and Russia have reformed their Economical and Social Systems, which enlarged the Trade Volume and Traffic Demand in this Area and between Europe. The Railway System Crossing the Eurasia Continent, such as TSR(Trans Siberian Railway), TCR(Trans China Railway), TMR(Trans Manchuria Railway), TMGR(Trans Mongolia Railway) and TKR(Trans Korea Railway), have been becoming very important to enhance the International Transportation efficiency and to connect each continents by International Railways. This Paper investigated and surveyed the logistical Environments surrounding this Korea Peninsula. And concerned with the Crossing Continents Railway, TSR,TCR(TMR, TMGR), TKR, operating Conditions and Tasks that must be considered and solved were also investigated. Especially the Current Logistical Conditions of China, Russia, and North Korea and their Problems were surveyed. And the SWOT of these Railways were analyzed and compared. The Visions and Goals of these Inter-Continental Railways were suggested in terms of their Rationalization of Operations and efficient Connections among many Countries. Not only the Policies and Strategies/Tactics which should be considered but also and Many detail countermeasures which should be introduced and adopted were suggested.

• The KIPS Transactions:PartC
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• v.13C no.2 s.105
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• pp.147-154
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• 2006

The certificate status validation mechanism is a critical component of a public key infrastructure based on certificate system. The most generally mechanisms used these days are the use of the certificate revocation list and the real-time certificate status protocol. But the certificate revocation list can not give the real-time certificate status because the certificate is being delivered periodically, and the real-time certificate status protocol method will generate a concentrated load to the server because the protocol in the central server will be accessed whenever a certification is necessary. It will also take a long time to validate the certificate because each trade has to send mass information through the network. This paper will present that real-time validation is guaranteed as the real-time certificate status protocol method and the traffic congestion in the network Is reduced in a way that the certification would be requested using the user information hash value and would be validated using the user information kept in the certification authorities and the service providers. Based on the this study, we suggest a real-time certificate status validation mechanism which can reduce the certificate status validation time using the signed user information hash value. And we confirm speed of certificate status verification faster than existing CRL(Certificate Revocation List) and OCSP(Online Certificate Status Protocol) method by test.