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Optimal Operation of Gas Engine for Biogas Plant in Sewage Treatment Plant (하수처리장 바이오가스 플랜트의 가스엔진 최적 운영 방안)

  • Kim, Gill Jung;Kim, Lae Hyun
    • Journal of Energy Engineering
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    • v.28 no.2
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    • pp.18-35
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    • 2019
  • The Korea District Heating Corporation operates a gas engine generator with a capacity of $4500m^3 /day$ of biogas generated from the sewage treatment plant of the Nanji Water Recycling Center and 1,500 kW. However, the actual operation experience of the biogas power plant is insufficient, and due to lack of accumulated technology and know-how, frequent breakdown and stoppage of the gas engine causes a lot of economic loss. Therefore, it is necessary to prepare technical fundamental measures for stable operation of the power plant In this study, a series of process problems of the gas engine plant using the biogas generated in the sewage treatment plant of the Nanji Water Recovery Center were identified and the optimization of the actual operation was made by minimizing the problems in each step. In order to purify the gas, which is the main cause of the failure stop, the conditions for establishing the quality standard of the adsorption capacity of the activated carbon were established through the analysis of the components and the adsorption test for the active carbon being used at present. In addition, the system was applied to actual operation by applying standards for replacement cycle of activated carbon to minimize impurities, strengthening measurement period of hydrogen sulfide, localization of activated carbon, and strengthening and improving the operation standards of the plant. As a result, the operating performance of gas engine # 1 was increased by 530% and the operation of the second engine was increased by 250%. In addition, improvement of vent line equipment has reduced work process and increased normal operation time and operation rate. In terms of economic efficiency, it also showed a sales increase of KRW 77,000 / year. By applying the strengthening and improvement measures of operating standards, it is possible to reduce the stoppage of the biogas plant, increase the utilization rate, It is judged to be an operational plan.

Management Guidelines and the Structure of Vegetation in Natural Monuments Koelreuteria Paniculata Community (천연기념물 모감주나무군락의 식생구조와 관리제언)

  • Shin, Byung Chul;Lee, Won Ho;Kim, Hyo Jeong;Hong, Jeum Kyu
    • Korean Journal of Heritage: History & Science
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    • v.43 no.1
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    • pp.100-117
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    • 2010
  • This study analyzed vegetation structure of natural monuments Koelreuteria paniculata community in search of a conservation and management plan. Plant sociological analysis of Koelreuteria paniculata community indicates that it can be classified into Achyranthes japonica subcommunity and Rhodotypos scandens subcommunity and Trachelospermum asiaticum var. intermedium subcommunity. While Koelreuteria paniculata community of Ahnmyeondo is composed of sub tree layer and herb layer, those of Pohang and Wando are composed of tree layer, Sub tree layer, shrub layer, herb layer. The results of tree vitality analysis showed that those in Ahnmyeondo appeared to be relatively low when compared to those in Pohang and Wando-gun. This can be understood in two different aspects: disease and insects vulnerability due to a relatively simple structure and lack of competitive species, and decreased vitality / natural branch losses due to crown competition arising from high density. The result of soil characteristics analysis showed that soil texture, soil pH, organic matter, $p_2O_5$, exchange positive ion were sufficient for tree growth while total nitrogen was not, so that discretion would be needed for fertilizer application. As there were damages of disease and inscet, but only for 10~15% of the entire area; it still requires consistent preconsideration. The study suggests the management methods for preservation of Koelreuteria paniculata community. First, securing designated areas is necessary in order to minimize environment deterioration due to surrounding development. Especially, for sections with decreased areas, expansion of designated areas through land purchase should also be considered. Second, artificial interference may affect the livestock. Therefore, monitoring of artificial interference is necessary, based on which protection projects must be conducted. Third, from analysis of young plants which influence the maintenance mechanisms of Koelreuteria paniculata community, a decrease compared to the prior year was observed; investigation is needed. Therefore, an active management policy through status examination of livestock such as germination and young plants is necessary.

A Study on the Effect of the Document Summarization Technique on the Fake News Detection Model (문서 요약 기법이 가짜 뉴스 탐지 모형에 미치는 영향에 관한 연구)

  • Shim, Jae-Seung;Won, Ha-Ram;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
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    • v.25 no.3
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    • pp.201-220
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    • 2019
  • Fake news has emerged as a significant issue over the last few years, igniting discussions and research on how to solve this problem. In particular, studies on automated fact-checking and fake news detection using artificial intelligence and text analysis techniques have drawn attention. Fake news detection research entails a form of document classification; thus, document classification techniques have been widely used in this type of research. However, document summarization techniques have been inconspicuous in this field. At the same time, automatic news summarization services have become popular, and a recent study found that the use of news summarized through abstractive summarization has strengthened the predictive performance of fake news detection models. Therefore, the need to study the integration of document summarization technology in the domestic news data environment has become evident. In order to examine the effect of extractive summarization on the fake news detection model, we first summarized news articles through extractive summarization. Second, we created a summarized news-based detection model. Finally, we compared our model with the full-text-based detection model. The study found that BPN(Back Propagation Neural Network) and SVM(Support Vector Machine) did not exhibit a large difference in performance; however, for DT(Decision Tree), the full-text-based model demonstrated a somewhat better performance. In the case of LR(Logistic Regression), our model exhibited the superior performance. Nonetheless, the results did not show a statistically significant difference between our model and the full-text-based model. Therefore, when the summary is applied, at least the core information of the fake news is preserved, and the LR-based model can confirm the possibility of performance improvement. This study features an experimental application of extractive summarization in fake news detection research by employing various machine-learning algorithms. The study's limitations are, essentially, the relatively small amount of data and the lack of comparison between various summarization technologies. Therefore, an in-depth analysis that applies various analytical techniques to a larger data volume would be helpful in the future.

Hanseong Period of Baekje and Mahan (한성시대(漢城時代)의 백제(百濟)와 마한(馬韓))

  • Choi, Mong-Lyong
    • Korean Journal of Heritage: History & Science
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    • v.36
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    • pp.5-38
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    • 2003
  • The history of Baekje Kingdom, one of the Three kingdoms, is divided into three periods to the change of sociopolitical center, including its capital as follows: Hanseong Period (18 BC ~ AD 475), Ungjin Period (AD 475~538), and Sabi Period (AD 538~660). Though the Hanseong Period of Baekje Kingdom covers more than two thirds of the whole history of Baekje Kingdom (493 years), history and archaeological culture of the Hanseong Period is still unclear and even ambiguous comparing to the Ungjin and Sabi periods. Most of all, it is because of quite limited historical records and archaeological data available. In addition, negative attitude of the Korean academic circles to the early records of Samguksaki(三國史記) has been a critical obstacle to the study of early history of the Three kingdoms, including the Hanseong Period of Baekje kingdom. Author, who has attempted to combine historical records and archaeological data in order to reconstruct the history and archaeological culture of the early Baekje, specifically the Hanseong Period, has held positive attitude to the early records of the Samguksaki as far as possible. He(Author) came to realize that comprehensive understanding of Mahan (馬韓) society, one of the Three Han (三韓) Society was more than essential in the study of Baekje. According to historical records and archaeological data, Mahan Society represented by Mojiguk(目支國) ruled by King Jin(辰王) has been located in the middle and/or southwestern parts of the Korean peninsula from the 3rd~2nd century BC through the end of the 5th century or early 6th century AD. Mahan already occupied central portion of the Korean Peninsula, including the Han River Valley when King Onjo(溫祖王) first set up the capital of Baekje Kingdom at Wiryeseong (慰 禮城) considered to be modern Jungrang~Songpa-gu area of Han River Valley. From the beginning of the Baekje history, there had been quite close interrelationships between Baekje and Mahan, and the interrelationships had lasted for around 500 years. In other words, it is impossible to attempt to understand and study Hanseong period of Baekje, without considering the historical and archaeological identity of Mahan. According to the Samguksaki, Baekje moved its capital three times during the Hanseong Period (18 BC ~ AD 475) within the Han River Valley as follows: Wiryeseong at Jungrang-gu area of the Han River (河北慰禮城, 18 ~ 5 BC), Wiryeseong at Songpa-gu area of the Han River(河南慰禮城, 5 BC ~ AD 371), Hansan at Iseongsan fortress site(Historical site No. 422, 漢山, AD 371~391), and Hanseong at Chungung-dong of Hanam city(漢城, AD 391~475). Before 1990s, archaeological data of the Hanseong Period was quite limited, and archaeological culture of Mahan was not well defined. Only a few burial and fortress sites were reported to be archaeological remains of the early Baekje, and a few settlement and jar burial sites were assumed to be those of Mahan without clear definition of the Mahan Culture. Since 1990s, fortunately, a number of new archaeological sites of Hanseong Baekje and Mahan have been reported and investigated. Thanks to the new discoveries, there has been significant progress in the study of early Baekje and Mahan. In particular, a number of excavations of Pungnap-dong Fortress site(Historical site NO. 11, 1996~2003), considered to be the Wiryeseong at south of the Han River, the second capital of the Hanseong Baekje, provided critical archaeological evidence in the study of Hanseong Period of Baekje. Since the end of the 1990s, a number of sites have been reported in Gyeonggi, Chungcheong, and Jeolla provinces, as well. From these sites, archaeological features and artifacts representing distinctive cultural tradition of Mahan have been identified such as unstamped fortresses, pit houses cut into the rock, houses with lifted floor(掘立柱 건물), and potteries decorated with toothed wheel and bird's footprint designs. These cultural traditions reflected in the archaeological remains played a critical role to define and understand archaeological identity of the Mahan society. Moreover, archaeological data from these new sites reported in the middle and southwestern parts of the Korean Peninsular made it possible to postulate a hypothesis that the history of Mahan could be divided into three periods to the change of its sociopolitical center in relation with the Baekje Kingdom's political Situation as follows: Cheonan (天安) Period, Iksan(益山) Period, and Naju(羅州) Period. The change of Mahan's sociopolitical center is closely related to the sociopolitical expansion of the Hanseong Baekje.

A Study of 'Yokagura of Takachiho': A sacred Music and Dancing Performed in Takachiho, the Land of Japanese Myths (일본신화의 고장 다카치호(高千穗)의 요가구라(夜神樂))

  • Park, Weon-mo
    • Korean Journal of Heritage: History & Science
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    • v.38
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    • pp.43-107
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    • 2005
  • A ritual ceremony accompanied by a song and dance is called as Kagura in Japan. The word Kagura is originally derived from Kamukura, which means the place where spirits reside. However, later it came to refer to the whole process of the ritual ceremony itself. Through the field studies, this paper examines Takachiho-kagura, helded in Takachiho, known as the village of myths, located in northern Miyazaki-ken in Japan. Kagura takes place all night through in each and every village in Takachiho and it normally runs from the end of November when the harvest season ends until early February the next year. One ordinary house is especially chosen for this ceremony, in which Kagura performs 33 repertoires. Takachiho-kagura is sometimes called as Yokagura, since the performance takes place over-night. A song and dance is performed by ordinary village people called hoshyadong, who inherited Takachiho-kagura. Currently, the ceremony is held in more than 20 villages and designated by the government as "Important Intangible Folk Cultural Property" in Japan. Takachiho-kagura follows the example of rituals held in Sada shrine in Izumo, which is now eastern Hiroshima-ken. It is the dance using a bell, a sword, a fan, which signify Norimono and is usually combined with mask-play called as Shinno. From the shrine of village, itwelcomes the gods who defense their village, called Ujikami and other 8 million gods, called Yaoyorozunokami, in Kagurayado, where Kagura of 33 repertoires is played in order. Kagura starts from dances for attendance of the gods, Hikomai, Daidono, Kamioroshi, performs dances of Amanoiwato, the gate of heaven's cave in Japanese myths, Dazikara, Uzume, Dotori, and continues dances for the old ghosts Shibahiki, Yatsubachi mixed with acrobatics. Finally, this performance ends with dances to send off the gods, Hinomae, Gurioroshi, Gumooroshi, until the dawn the next morning. This paper explores Takachiho-kagura from the perspective of folk performance with ethnography. These days, ecstasy and oracle do not happen in Takachiho-kagura. However, it kept the old form of folk performance as Kagura held in ordinary house. Especially, in Takachiho, remarkable venue of the Japanese myths, Takachiho-kagura is developed artistically. The first field study was held in Gokamura, Iwato-zone and Ashakabe, Mitai-zone between December 6th and December 12th 1997. Afterwards, the second field study was conducted in the area of Shiba and Ashakabe from December 17th until December 19th 1997 and from December 1st until December 10th 2000.

A Study on the Consciousness Survey of Improvement of Emergency Rescue Training -Based on the Fire Fighting Organizations in Gangwon Province- (긴급구조훈련 개선에 관한 의식조사 연구 -강원도 소방조직을 중심으로-)

  • Choi, Yunjung;Koo, Wonhoi;Baek, Minho
    • Journal of the Society of Disaster Information
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    • v.15 no.3
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    • pp.440-449
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    • 2019
  • Purpose: Fire-fighting organizations are the very first agencies that take actions at a disaster scene, and emergency rescue training is carried out for prompt and systematic response. However, there is a need for a change due to the limitations in emergency rescue trainings such as perfunctory trainings or trainings without considering regional or environmental characteristics. Method: This study is to conduct theoretical review with regard to emergency rescue training and present a measure to improve the emergency rescue training through attitude survey targeting fire-fighting organizations in Gangwon area. Result: Facilities that cause difficulties when doing emergency rescue activity were mostly hazardous material storage and processing facilities. In terms of the level of emergency rescue and response task, most respondents answered that the emergency rescue was insufficient. The respondents answered that the effectiveness of emergency rescue training was helpful, but some responses showed that the training was not helpful because of scenario-based training, seeming training, similar training carried out every year, unrealistic training, and lack of competent authorities' interest and perfunctory participations. Most respondents answered for the appropriateness of emergency rescue training and evaluation that they were satisfied, however, they were not satisfied with the evaluation methods irrelevant to the type of training, evaluation methods requiring unnecessary training scale, and evaluation methods leading perfunctory participations of competent authorities. Lastly, respondents mostly answered that training reflecting various damage situations are necessary regarding the demand on the improvement of emergency rescue training. Conclusion: The improvement measures for emergency rescue training are as follows. First, it is necessary to set and prepare various training contents in accordance with regional characteristics by reviewing major disasters occurred in the region. Second, it is necessary to revise the emergency rescue training guidelines and manuals for appropriate training plan for each fire station, provide education and training for working-level staff members, and establish training in a way that types, tactics, and strategies of emergency rescue training could be utilized practically. Third, it is necessary to prepare a scheme that can lead participation and provide incentive or penalty from the planning stage of training in order to increase the participation of supporting and competent authorities when an actual disaster occurs. Fourth, it is necessary to establish support arrangements and cooperative systems by authority through training by fire stations or zones in preparation for disaster situations that may occur simultaneously. Fifth, it is necessary to put emphasis on the training process rather than the result for emergency rescue training and evaluation, pay attention to the identification of supplement points for each disaster situation and make improvements. Especially, type or form of training should be considered rather than evaluating the execution status of detailed processes, and the evaluation measure that can consider the completeness (proficiency) of training and the status of role performance rather than the scale of training should be prepared. Sixth, type and method of training should be improved in accordance with the characteristics of each fire station by identifying the demand of working-level staff members for an efficient emergency rescue training.

A study on mandatory insurance for aircraft operators (항공보험 가입의무에 관한 연구)

  • Lee, Chang-Jae
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.2
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    • pp.169-197
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    • 2018
  • The purpose of this study is to present a reasonable and concrete standard for the Korean aviation insurance compulsory subscription system. Through this, we aim to improve the current revision of laws and regulations, and ultimately create an environment in which the safety and property of the Korean people who use aircraft with appropriate aviation insurance can be secured. In particular, by reviewing the aviation business law and its new laws and regulations enacted in 2017, the legislative improvement direction of aviation insurance will be proposed. In order to maintain the continuous growth of the air transportation industry and to make amicable compensation for the victims, considering the characteristics of the total accident, instantness, and giganticness of air accidents in which a lot of people and property are lost in the event of an accident, adequate insurance coverage is essential. In this respect, the compulsory insurance to amend the principle of freedom of contract, which is the great principle of the modern judicial system, will be persuasive. However, in comparison with foreign legislation, the legal provisions on Korea's obligation to comply with aviation insurance need to be revised around the following issues: First, it is reasonable to enforce the regulation of the mandatory aviation insurance by legislation from the Congress not by administrative regulations. Because it will force the monetary obligations of the individual such as common air carriers. Second, our law regulations respond to various kinds of air damages by using the phrase "limit of liability stipulated in international conventions". However, as we have seen in the text, the range of compensation are various according to the use of legal instruments in international conventions such as the Montreal Convention, which governs the compensation of passengers for damages to passengers today. Third, in countries with narrow territories, such as Korea, there are big differences in flying time and insurable risk between domestic and international transportation. Therefore, it is necessary to divide domestic transportation and international transportation even in the obligation to join the insurance. This dual discipline has the advantage for rookies in air carrier market who mainly start their business from domestic service. Fourth, according to Korean law, the regulations of automobile loss insurance is applicable to the aviation mandatory insurance of unmanned aerial vehicle accident which is lack of persuasion. In the future, it will be appropriate to discipline insurance for unmanned aerial vehicles with unlimited potential for development from a long-term perspective.

A Study on Personalized Product Demand Manufactured by Smart Factory (스마트팩토리 환경의 개인맞춤형 제품 구매의도의 영향요인에 관한 연구)

  • Woo, Su-Han;Kwon, Sun-Dong
    • Management & Information Systems Review
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    • v.38 no.1
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    • pp.23-41
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    • 2019
  • Smart Factory is different from existing factory automation in that it aims to produce personalized products with minimum time and cost through ICT. However, previous researches, not from consumers but from product suppliers, have focused on technology trends and technology application methods. In order for Smart Factory to be successful, it must go beyond supplier-focus to meet the needs of consumers. In this study, we surveyed the purchase intention of the personalized product manufactured by smart factory. Influencing factors of purchase intention were drawn as consumers' need for uniqueness, innovativeness, need for touch, and privacy concern, based on previous research. As results of data analysis, it was confirmed that respondents were willing to purchase personalized products, and that consumers' need for uniqueness, innovativeness, and need for touch had a significant impact on purchase intention of personalized products. Our findings can be summarized as follows. First, Consumers' need for uniqueness was found to have positive effects(${\beta}=0.168$) on purchase intention of personalized products. The desire to differentiate themselves from others will be reflected in their personalized products. Therefore, consumers with a higher desire for uniqueness tend to be more willing to purchase personalized products. Second, consumer innovativeness was found to have positive effects(${\beta}=0.233$) on purchase intention of personalized products. Personalized shoes suggested in this study is a new type of personalized product that is manufactured by the latest information and communication technologies such as multi-function robots and 3D printing. Therefore, consumers seeking innovative new experiences are more willing to purchase personalized products. Third, need for touch was found to have positive effects(${\beta}=0.299$) on purchase intention of personalized products. In a smart factory environment, prosuming participation is given to consumers. If consumers participate in the product development process and reflect their requirements on the product, they are expected to increase their purchase intention by virtually satisfying the need for touch. Fourth, privacy concern was found to have no significantly related to purchase intention of personalized products. This is interpreted as a willingness to tolerate the risk of exposing personal information such as home address, telephone number, body size, and preference for consumers who feel highly useful in personalized products.

A Study on Management Present and Improvements of National Records Designation System (국가지정기록물 관리현황과 개선방안 연구)

  • Choi, Jae-Ho;Lee, Young-Hak
    • The Korean Journal of Archival Studies
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    • no.47
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    • pp.51-93
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    • 2016
  • This study is on management present and improvements on National Records Designation System. National Records Designation System is a system that supports management and preservation of changes of records designated by the government through consideration that such records are worth preserving permanently nationally among records acquired by individual or organization. This system is meaningful in a way that it established systematic foundation to hand down by informatizing historic private records which are in danger to be lost or damaged due to lack of proper care. However, compared to the number of designated records, the information that could be practically drawn from such records are limited. This triggered this study to be launched. National Archive sometimes promotes designation and management of National Designated records. Yet archival information service offering access of user to national designated records are very rare. I conducted survey and interview of managers, field research, and documentary research of 10 records holding institution that keeps national designated records currently. I considered that current management status of National Records Designation System can be figured out minutely through these research. As a result of such research, most of the records holding institutions offered display as their least archival information service. The objective of records informatization was to utilize the records. Also further plans on information service related to records and various utilization were suggested. records holding institution manager did not give positive answer on effect of designating national designated records and cooperation between National Archive. Support to National Archive only focused on preservation. For national designated records holding institution designated after 2011 were not getting proper support. In addition, National Archive's support rarely met records holding institution's need. In such circumstances, things to consider for improvements of National Records Designation System is as following. First, designation of national designated records should be based on the utilization of the record. Each records holding institution's willingness to utilize corresponding records and National Archive's ability to draw the willingness out should be considered. Also, it shouldn't be left as mere complementary policy of National Archive's selecting policy. Second, for National Records Designation System to be managed permanently, it should be changed as the system that supports enhancement of private records management. The aim should point to the direction where private can manage and preserve the records on their own. Third, There needs to be changes on the subject and process of national designated records designation. National designated record is the record that was considered valuable by the government among private records. Thus, such records should be the best one to show private field. Accordingly, records that represent contemporary society and include various states and contents should be chosen to be designated. Moreover, public discussion be formed by citizens and related professionals in order to properly select the record.

A study on non-existence information of the information disclosure system : focused on the central administrative agencies (정보공개제도상의 정보부존재에 관한 고찰 중앙행정기관을 중심으로)

  • Kim, You-seung;Choi, Jeong Min
    • The Korean Journal of Archival Studies
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    • no.46
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    • pp.153-187
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    • 2015
  • This study aims to discuss issues about non-existent information of the information disclosure system and to provide alternative strategies for the issues. For the theoretical discussion it reviews the definitions and standards of non-existent information and analyzes legal aspects and statistical changes of non-existent information. Furthemore, in order to discuss a current status and problems of non-existent information at the central administrative agencies, it analyzes the cases of the non-existent information notification. According to analysis results, non-existent information status of the surveyed institutions is a total of 4,421 cases for three years and it shows the continuous increasing trend year after year. The number of institutions that have the number of non-existent information equal to the number of nondisclosures or over it reached about 40%. It means excluding non-existent information from the reasons of nondisclosure influenced disclose rates and nondisclosure rates of many agencies. In the type analysis of the non-existent information reasons, the most main reason, the case of not producing or receiving the requested information by public institutions takes over 75% among the whole reasons. The next reason is the case of collecting or processing information takes over 7-10%. This study found the operational issues, as analyzing notifications of non-existent information. The operational issues are 1) the incomplete explanation of non-existent information, 2) the unclear scope of the collection and processing, 3) the problem of the transfer processing, and 4) the problem of recording management. Therefore, this study suggested some improvements of the perspective and the technical and procedural aspects. First, information disclosure issues including non-existent information are to be understood as an extension of records management. Second, disclosure service should improve overall based on advanced understanding. Third, the management procedures of non-existent information should be improved. Fourth, specific guidelines for handling non-existent information should be developed.