• Clean Technology
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• v.24 no.1
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• pp.41-49
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• 2018

Y zeolites with different extra-framework cations, such as $Na^+$, $N^+$, $Ca^{2+}$, and $Cu^{2+}$, with different charge and ionic radius have been investigated to greatly enhance a working capacity (W) of $CO_2$ adsorption at $25^{\circ}C$ and a $CO_2/CO$ selectivity factor (S). A sample of NaY with a very small amount of 0.012% $Ca^{2+}$ was fully reversible for seven times repeated $CO_2$ adsorption/desorption cycles, thereby forming no surface carbonates unlikely earlier reports. Although at pressures above 4 bar, 2.00% CaY, 1.60% CuY and 1.87% LiY all showed a $CO_2$ adsorption very similar to that measured for NaY, they gave a significant decrease in the adsorption at lower pressures, depending on the metal ion. At 0.5 ~ 2.5 bar, the extent of $CO_2$ adsorption was in the order NaY > 1.60% CuY > 2.00% CaY > 1.87% LiY. All the $Na^+-based$ metals-exchanged zeolites have a FAU (faujasite) framework and a Si/Al value near 2.6; thus, there is no discernible difference in the framework topology, framework chemical compositions, effective aperture size, and channel structure between the zeolite samples. Therefore, the distinctive behavior in the adsorption of $CO_2$ with a character as a weak Lewis acid is associated with the site basicity of the zeolites, and the interaction potentials of the cations. Different trend was shown for a CO adsorption due to weaker quadrupole interactions. Adsorption of $CO_2$ and CO on samples of CaY with 0.012 to 5.23% Ca disclosed a significant dependence on the Ca loading. The $CO_2$ adsorption increased when the cation exists up to ca. 0.05%, while it decreased at higher Ca amounts. However, values for both W and S could greatly increase as the bare zeolite is enriched by $Ca^{2+}$ ions. The 5.23% CaY had $W=2.37mmol\;g^{-1}$ and S = 4.37, and the former value was comparable to a benchmark reported in the literature.

• Journal of Intelligence and Information Systems
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• v.23 no.3
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• pp.139-153
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• 2017

Corporate bankruptcy can cause great losses not only to stakeholders but also to many related sectors in society. Through the economic crises, bankruptcy have increased and bankruptcy prediction models have become more and more important. Therefore, corporate bankruptcy has been regarded as one of the major topics of research in business management. Also, many studies in the industry are in progress and important. Previous studies attempted to utilize various methodologies to improve the bankruptcy prediction accuracy and to resolve the overfitting problem, such as Multivariate Discriminant Analysis (MDA), Generalized Linear Model (GLM). These methods are based on statistics. Recently, researchers have used machine learning methodologies such as Support Vector Machine (SVM), Artificial Neural Network (ANN). Furthermore, fuzzy theory and genetic algorithms were used. Because of this change, many of bankruptcy models are developed. Also, performance has been improved. In general, the company's financial and accounting information will change over time. Likewise, the market situation also changes, so there are many difficulties in predicting bankruptcy only with information at a certain point in time. However, even though traditional research has problems that don't take into account the time effect, dynamic model has not been studied much. When we ignore the time effect, we get the biased results. So the static model may not be suitable for predicting bankruptcy. Thus, using the dynamic model, there is a possibility that bankruptcy prediction model is improved. In this paper, we propose RNN (Recurrent Neural Network) which is one of the deep learning methodologies. The RNN learns time series data and the performance is known to be good. Prior to experiment, we selected non-financial firms listed on the KOSPI, KOSDAQ and KONEX markets from 2010 to 2016 for the estimation of the bankruptcy prediction model and the comparison of forecasting performance. In order to prevent a mistake of predicting bankruptcy by using the financial information already reflected in the deterioration of the financial condition of the company, the financial information was collected with a lag of two years, and the default period was defined from January to December of the year. Then we defined the bankruptcy. The bankruptcy we defined is the abolition of the listing due to sluggish earnings. We confirmed abolition of the list at KIND that is corporate stock information website. Then we selected variables at previous papers. The first set of variables are Z-score variables. These variables have become traditional variables in predicting bankruptcy. The second set of variables are dynamic variable set. Finally we selected 240 normal companies and 226 bankrupt companies at the first variable set. Likewise, we selected 229 normal companies and 226 bankrupt companies at the second variable set. We created a model that reflects dynamic changes in time-series financial data and by comparing the suggested model with the analysis of existing bankruptcy predictive models, we found that the suggested model could help to improve the accuracy of bankruptcy predictions. We used financial data in KIS Value (Financial database) and selected Multivariate Discriminant Analysis (MDA), Generalized Linear Model called logistic regression (GLM), Support Vector Machine (SVM), Artificial Neural Network (ANN) model as benchmark. The result of the experiment proved that RNN's performance was better than comparative model. The accuracy of RNN was high in both sets of variables and the Area Under the Curve (AUC) value was also high. Also when we saw the hit-ratio table, the ratio of RNNs that predicted a poor company to be bankrupt was higher than that of other comparative models. However the limitation of this paper is that an overfitting problem occurs during RNN learning. But we expect to be able to solve the overfitting problem by selecting more learning data and appropriate variables. From these result, it is expected that this research will contribute to the development of a bankruptcy prediction by proposing a new dynamic model.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.5
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• pp.82-93
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• 2008

This research focused on the process in which 'the same scenery' is recognized and represented as 'a different landscape' to determine the symbols and meaning of the scenery and landscape included in real-scenery landscape paintings of the 18th-19th centuries. As a result of analyzing the visual points, the content and expressions of 25 real-scenery landscape paintings of Chong Seok Jeong(叢石亭), it can be seen that the transmission of a kind of semiotic landscape on the basis of a specific symbol was accomplished naturally through imitation and representation for the purpose of the expression of Chong Seok Jeong-like idealized scenery. This shows that the unique images of Chong Seok Jeong have long been passed down after taking root as a unique benchmark The meaningful symbol of 'a strange Saseonbong(四仙峰)', which is broken by the spray after rising high, and 'a pine forest' have both been transmitted as being in the manner of Chong Seok Jeong. This has been equipped with the stereo-type scene by being a collective symbolization as the psycho-scenes in memory element of Chong Seok Jeong. Through the pictures of both Gyeomjae(謙齋) and Danweon(檀園), the process by which a specific painter's pictures become acculturated is highly interesting. The scenery expressed in these pictures was clearly that of a landscape of which its particularly emotions and remembrances were repainted through the experience of several places and original sketches. This can be explained as the concept in which the image from 'a specific scenery' gained through actual experience, that is, a personal feeling, has been expressed. The picture that was expressed as a different figure even at the same visual point for the same scenery is the result that was redefined through the scenery subject's recognition. Also, the modification of the scenery object can be colorful through meditation and Sachu(邪推: guessing with wicked doubt). The scenery recognized newly through adoption, omission and emphasis, it is 'the specific scenery' in the heart and is a figure having been more similar to 'a landscape' if the objective life reproduction before being acculturated is a figure similar to the scenery. So, the concept looks like being very persuasive that 'the nature with objectivity captured sensuously' simply is the scenery, and that 'the subjective phenomenon having acquired the cultural nature by being introspected in the method of aesthetic nostalgia is a landscape'.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.43-56
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• 2020

Recommender systems help users make the best choice among various options. Especially, recommender systems play important roles in internet sites as digital information is generated innumerable every second. Many studies on recommender systems have focused on an accurate recommendation. However, there are some problems to overcome in order for the recommendation system to be commercially successful. First, there is a lack of transparency in the recommender system. That is, users cannot know why products are recommended. Second, the recommender system cannot immediately reflect changes in user preferences. That is, although the preference of the user's product changes over time, the recommender system must rebuild the model to reflect the user's preference. Therefore, in this study, we proposed a recommendation methodology using topic modeling and sequential association rule mining to solve these problems from review data. Product reviews provide useful information for recommendations because product reviews include not only rating of the product but also various contents such as user experiences and emotional state. So, reviews imply user preference for the product. So, topic modeling is useful for explaining why items are recommended to users. In addition, sequential association rule mining is useful for identifying changes in user preferences. The proposed methodology is largely divided into two phases. The first phase is to create user profile based on topic modeling. After extracting topics from user reviews on products, user profile on topics is created. The second phase is to recommend products using sequential rules that appear in buying behaviors of users as time passes. The buying behaviors are derived from a change in the topic of each user. A collaborative filtering-based recommendation system was developed as a benchmark system, and we compared the performance of the proposed methodology with that of the collaborative filtering-based recommendation system using Amazon's review dataset. As evaluation metrics, accuracy, recall, precision, and F1 were used. For topic modeling, collapsed Gibbs sampling was conducted. And we extracted 15 topics. Looking at the main topics, topic 1, top 3, topic 4, topic 7, topic 9, topic 13, topic 14 are related to "comedy shows", "high-teen drama series", "crime investigation drama", "horror theme", "British drama", "medical drama", "science fiction drama", respectively. As a result of comparative analysis, the proposed methodology outperformed the collaborative filtering-based recommendation system. From the results, we found that the time just prior to the recommendation was very important for inferring changes in user preference. Therefore, the proposed methodology not only can secure the transparency of the recommender system but also can reflect the user's preferences that change over time. However, the proposed methodology has some limitations. The proposed methodology cannot recommend product elaborately if the number of products included in the topic is large. In addition, the number of sequential patterns is small because the number of topics is too small. Therefore, future research needs to consider these limitations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6158-6167
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• 2014

The aim of this study was to perform comparative analysis of the duties of 7 new roles of HIMs in Malaysian and Korean hospitals of a similar scale. A Malaysian general hospital with a scale of 272 hospital beds was chosen. The researcher visited a Malaysian hospital in person and interviewed the staff in charge over a 2 week period from July 22nd 2013 to August 2nd 2013. For domestic hospitals, 13 general hospitals with 270 hospital beds, similar to the Malaysian general hospital, were chosen. Phone interviews with the department recorded the duty recording work. Regarding 7 new roles of Health Information Manager (HIM), although the role as a Health information manager and Security Officer in Malaysian general hospital was not defined, 30.8% performed their role in Korean general hospitals. The classification of disease & procedure within the role of Clinical data specialist was performed by both countries, and while the tumor registry was done in a Malaysian general hospital, only 15.4% of Korean general hospitals were operating. The statistics of the discharged patients were not measured in the Malaysian general hospital but 76.9% of Korean general hospitals recorded these statistics. Although 22.1% of Korean general hospitals operated registration work of special disease, Malaysian general hospital not only had a total legal contagious disease registration, but also took charge of information registration of hospital births and deceased ones. Other than these, the Patient Information Coordinator, Data Quality Manager, Document and Repository Manager, Research and Decision Support Analyst roles were not done by either country. The new role of HIM is operated in a low percentage in Korean middle and small hospitals. Therefore, to clearly establish the role of HIM in Korea, and have middle and small hospitals to operate such a role, it is essential for the related association to give continuous education and provide support to clarify the role within the hospital working environment. It is desirable to benchmark Malaysian general hospital's registration work on special diseases and others, and expand the work to improve overall.

• Journal of Korean Society of Steel Construction
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• v.23 no.4
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• pp.417-428
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• 2011

Depending on the plastic deformation capacity required, structural steel design under the current codes can be classified into three categories: elastic, plastic, and seismic design. Most of the current steel codes explicitly forbid the use of a steel material with a yield strength higher than 450 MPa in the plastic design because of the concerns about its low plastic deformation capacity as well as the lack of test data on local and lateral torsional buckling behavior. In this study, flexural tests on full-scale H-shape members built with SM490A (ordinary steel or benchmark material) and HSB800 (high-strength steel) were carried out. The primary objective was to investigate the appropriateness of extrapolating the local buckling criterion of the current codes, which was originally developed for normal-strength steel, to the case of high-strength steel. All the SM490A specimens performed consistently with the current code criteria and exhibited sufficient strength and ductility. The performance of the HSB800 specimens was also very satisfactory from the strength perspective; even the specimens with a noncompact and slender flange developed the plastic moment capacity. The HSB800 specimens, however, showed an inferior plastic rotation capacity due to the premature tensile fracture of the beam bottom flange beneath the vertical stiffener at the loading point. The plastic rotation capacity that was achieved was less than 3 (or the minimum level required for a plastic design). Although the test results in this study indicate that the extrapolation of the current flange local-buckling criterion to the case of high-strength steel is conservative from the elastic design perspective, further testing together with an associated analytical study is required to identify the causes of the tensile fracture and to establish a flange slenderness criterion that is more appropriate for high-strength steel.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.163-192
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• 1983

In order to facilitate the Korean government's efforts in integrating family planning and maternal & child health at the primary health care level (or township level), the Soon Chun Hyang College of Medicine, with the financial and technical assistance of WHO, has under-taken a service research project. The project has employed a quasi-experimental study design introducing interventions tat provide crucial factors lacking in the ongoing government programs such as midwives and qualified referral physicians. The study is being conducted in three locations, one control area and two study areas. Before introducing trained Nurse/Midewives into the study areas, a baseline prevalence survey was undertaken from 15 July 1981 to 10 August 1981 in selelcted townships of Seosan County. In this sample survey of bath the study and control areas, 2,484 eligible women (97% reponse rate) were interviewed to obtain benchmark data on basic evaluation indicators related to family planning and maternal and child health. The salients results were summarized as follows.: 1. CONTACT RATES WITH HEALTH WORKERS; During the year preceding the survey, 12% of women were visited by government health workers. The primary reason for such visits by health workers was family planning (45% of the visits). About 34% of the women visited the health centers during the year. The primary reason for visiting health centers was immunizations for their children (45% of the visits). 3. FAMILY PLANNING USE RATE; The baseline data showed little difference between women in the study area and the control area on contraceptive use. Approximately 59% were currently using some methods. However, among those current users, almost half were practicing less effective methods of birth control such as rhythm or withdrawal. Among other methods, the tubectomy was the most popular (16%), while use of the IUD, oral pill and condom together reached only 14%. 3. PRENATAL CARE RATE; About 75% of the women reported no prenatal care for their last births (the youngest child of each women), Additionally, among women received prenatal care, over half had only one visit. 4. ATTENDANCE AT DELIVERY; Most of the women surveyed (over 80%) were attended by a non-medical person during their last delivery. These figures are somewhat comparable to the national figure of 84% for remote areas. 5. POSTNATAL CARE; The proportion of women reporting postnatal care was only 4.5%, and postnatal care was not received by the majority of women surveyed. 6. CHILD HEALTH CARE: In contrast to the low rate of maternity care for women themselves, most women reported obtaining immunization care for their children. About 75% of the women obtained Polio and/or DPT, 58% BCG, and 44% Measles vaccine for their children. However, in terms of illness care, while 35% of the women stated that their youngest child had been sick during the month preceding the survey, only 28% of these women took their child to the clinic for treatment. 7. COMPLICATIONS OF PREGNANCY AND DELIVERY AND ABNORMALITIES IN THE NEWBORN; Among all last deliveries, 18% of the women had pregnancy complications and 9% of the women had complications during delivery About 5% of the women reported abnormality in their most recent newborn. 8. REPRODUCTION EFFICIENCY; PERINATAL MORTALITY AND INFANT MORTALITY Based on data from the pregnancy history in this survey, reproduction efficiency was estimated. Out of the 11,154 pregnancies reported by all women surveyed, foetal loss was 21% (almost 16% were induced abortions) and infant deaths before reaching one year old were 3.1%. The reproduction efficiency was, therefore, reduced to 76%. In terms of perinatal and infant mortality rates, the former was 40.2 per 1,000 total births and the latter was 39.3 per 1,000 live births. Both rates described J shaped relationships with age of mothers and parity, and they were also correlated with birth interval and mother's education. In summary, this baseline survey data indicated a need for (1) improving contraceptive practices with more effective methods to prevent unwanted pregnancies and (2) providing better services for maternal and child care to protect wanted pregancies. In the Korean rural setting. the author believes that the latter is more important as the value of each child has increased as a result of the family planning campaign for the past two decades. This calls for more effective integration of Family Planning and MCH programmes to meet the needs of the family in each stage of the child bearing and rearing period with deploying more qualified personnel than the current government program personnel.

• Journal of KIISE:Databases
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• v.28 no.4
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• pp.529-544
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• 2001

Prefetching is an effective method to minimize the number of roundtrips between the client and the server in database management systems. In this paper we propose new notions of the type-level access pattern and the type-level access locality and developed an efficient prefetchin policy based on the notions. The type-level access patterns is a sequence of attributes that are referenced in accessing the objects: the type-level access locality a phenomenon that regular and repetitive type-level access patterns exist. Existing prefetching methods are based on object-level or page-level access patterns, which consist of object0ids of page-ids of the objects accessed. However, the drawback of these methods is that they work only when exactly the same objects or pages are accessed repeatedly. In contrast, even though the same objects are not accessed repeatedly, our technique effectively prefetches objects if the same attributes are referenced repeatedly, i,e of there is type-level access locality. Many navigational applications in Object-Relational Database Management System(ORDBMs) have type-level access locality. Therefore our technique can be employed in ORDBMs to effectively reduce the number of roundtrips thereby significantly enhancing the performance. We have conducted extensive experiments in a prototype ORDBMS to show the effectiveness of our algorithm. Experimental results using the 007 benchmark and a real GIS application show that our technique provides orders of magnitude improvements in the roundtrips and several factors of improvements in overall performance over on-demand fetching and context-based prefetching, which a state-of the art prefetching method. These results indicate that our approach significantly and is a practical method that can be implemented in commercial ORDMSs.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.603-617
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• 2018

This study surveyed the diversity and community characteristics of benthic macroinvertebrates and freshwater fish, which are the main animal classifications in a hydro ecosystem, from May to September 2017 in the western plains of the Demilitarized Zone (DMZ). The results showed a total of 125 species of benthic macroinvertebrates belonging to 66 families, 19 orders, and four phyla in the streams and wetlands. Among benthic macroinvertebrates, Coleoptera (27 spp.: 21.60%) was the largest group in terms of species richness followed by Odonata (26 spp.: 20.80%), non-Insecta (22 spp.: 17.60%), and Hemiptera (11 spp.: 8.80%) occupying in the lentic area. Of the feeding function groups (FFGs), predators (51 spp.: 56.67%) showed a relatively larger presence, indicating the dominance of hygrophilous invertebrates that usually inhabit the freshwater wetlands or ponds. Of the habitat oriented groups (HOGs), climbers (33 spp.: 24.44%) and burrowers (17 spp.: 12.59%) were the dominant groups. This observation is typical in a slow flowing habitat and can lead to the disturbance of the ecosystem due to cannibalism among predators. Cannibalism can be caused by stress induced by various population and environmental factors. For the ecosystem services benchmark (ESB) value, site 13 appeared to be the highest with 82 marks while other sites showed relatively lower rates and indices (III water quality class with ${\alpha}$-mesosaprobic). The analysis result of stability factors showed that almost all sites were evaluated to be the I characteristic group with high resilience and resistance or the III characteristic group that was sensitive to environmental disturbance and formed uneven and unstable communities. Of the freshwater fishes, 46 species (3,405 individuals) belonging to 39 families and 18 orders were identified in all the investigated sites. Among them, Cyprinidae (30 spp.: 65.2%) was the largest group, and Zacco koreanus was identified as the dominant species (728 individuals, 21.4%). The survey of freshwater fish communities found both stable communities (sites 7 and 13) with low dominant index (0.39) and high diversity index (2.29) and unstable communities (sites 2, 3, 8, and 10) in opposite tendency. This survey found five Korean endemic species, 17 species belonging to the export controlled species, two endangered species level II (Lethocerus deyrollei and Cybister chinensis), and rare species (Dytiscus marginalis czerskii) among benthic macroinvertebrates. The survey also found an invasive species, Ampullarius insularus, which was distributed throughout the whole area and thus can continuously disturb the ecosystem in the western plain area in the DMZ. Of freshwater fish, one natural monument (Hemibarbus mylodon) and three endangered species level II (Acheilognathus signifer, Gobiobotia macrocephalus, and G. brevibarba) were observed. The survey also found four introduced species (Pomacea canaliculate, Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides) in the western DMZ area, indicating the need for the protection and conservation measures.

• The Korean Journal of Archival Studies
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• no.18
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• pp.139-178
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• 2008

The functional requirements standards for electronic records management systems which have been published recently describe the specifications very precisely including not only core functions of records management but also the function of system management and optional modules. The fact that these functional requirements standards seem to be similar to each other in terms of the content of functions described in the standards is linked to the global standardization trends in the practical area of electronic records. In addition, these functional requirements standards which have been built upon with collaboration of archivists from many national archives, IT specialists, consultants and records management applications vendors result in not only obtaining high quality but also establishing the condition that the standards could be the certificate criteria easily. Though there might be a lot of different ways and approaches to benchmark the functional requirements standards developed from advanced electronic records management practice, this paper is showing the possibility and meaningful business cases of gaining useful practical ideas learned from imaging electronic records management practices related to the functional requirements standards. The business cases are explored central functions of records management and the intellectual control of the records such as classification scheme or disposal schedules. The first example is related to the classification scheme. Should the records classification be fixed at same number of level? Should a record item be filed only at the last node of classification scheme? The second example addresses a precise disposition schedule which is able to impose the event-driven chronological retention period to records and which could be operated using a inheritance concept between the parent nodes and child nodes in classification scheme. The third example shows the usage of the function which holds or freeze and release the records required to keep as evidence to comply with compliance like e-Discovery or the risk management of organizations under the premise that the records management should be the basis for the legal compliance. The last case shows some cases for bulk batch operation required if the records manager can use the ERMS as their useful tool. It is needed that the records managers are able to understand and interpret the specifications of functional requirements standards for ERMS in the practical view point, and to review the standards and extract required specifications for upgrading their own ERMS. The National Archives of Korea should provide various stakeholders with a sound basis for them to implement effective and efficient electronic records management practices through expanding the usage scope of the functional requirements standard for ERMS and making the common understanding about its implications.