• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.151-164
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• 2009

The importance of sensor networks as a base of ubiquitous computing realization is being highlighted, and espicially the security is recognized as an important research isuue, because of their characteristics.Several efforts are underway to provide security services in sensor networks, but most of them are preventive approaches based on cryptography. However, sensor nodes are extremely vulnerable to capture or key compromise. To ensure the security of the network, it is critical to develop security Intrusion Detection System (IDS) that can survive malicious attacks from "insiders" who have access to keying materials or the full control of some nodes, taking their charateristics into consideration. In this perper, we design a distributed and adaptive IDS architecture on sensor networks, respecting both of energy efficiency and IDS efficiency. Utilizing a modified HEED algorithm, a clustering algorithm, distributed IDS nodes (dIDS) are selected according to node's residual energy and degree. Then the monitoring results of dIDSswith detection codes are transferred to dIDSs in next round, in order to perform consecutive and integrated IDS process and urgent report are sent through high priority messages. With the simulation we show that the superiorities of our architecture in the the efficiency, overhead, and detection capability view, in comparison with a recent existent research, adaptive IDS.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.4
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• pp.65-73
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• 2002

It has been recognized that the damage control must become a more explicit design consideration. In an effort to develop design methods based on performance it is clear that the evaluation of the nonlinear response is required. The methods available to the design engineer today are nonlinear time history analyses, monotonic static nonlinear analyses, or equivalent static analyses with simulated nonlinear influences. Some building codes propose the capacity spectrum method based on the nonlinear static analysis(pushover analysis) to determine the earthquake-induced demand given by the structure pushover curve. These procedures are conceptually simple but iterative and time consuming with some errors. This paper presents a nonlinear direct spectrum method(NDSM) to evaluate seismic performance of structures, without iterative computations, given by the structural initial elastic period and yield strength from the pushover analysis, especially for MDF(multi degree of freedom) systems. The purpose of this paper is to investigate the accuracy and confidence of this method from a point of view of various earthquakes and unloading stiffness degradation parameters. The conclusions of this study are as follows; 1) NDSM is considered as practical method because the peak deformations of nonlinear system of MDF by NDSM are almost equal to the results of nonlinear time history analysis(NTHA) for various ground motions. 2) When the results of NDSM are compared with those of NTHA. mean of errors is the smallest in case of post-yielding stiffness factor 0.1, static force by MAD(modal adaptive distribution) and unloading stiffness degradation factor 0.2~0.3.

• Journal of Korean Theatre Studies Association
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• no.48
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• pp.51-84
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• 2012

In Korea, historical plays took an epoch-making turn from the previous historical plays in terms of approaches to topic and material and methods of rewriting history in the 1990s. Historical plays became dehistoricized with individual, everyday life, and faction emerging as major codes of historical plays according to mistrust in history and grand narrative as the original and disappearance of trust in the growth and totality of history. A new trend became dominant of presenting fictionality prominent instead of reproduction of history and freely playing with history outside the context. While modern historical plays were subject to the content of history, post-modern historical plays sought after new history writing to tell a new story on history within a framework of fiction. Focusing on some of the trends in post-modern historical plays since the 1990s, which include play with history, daily life-style history writing, and reproduction patterns of colonial modernity, this study examined the goals, representations, and text strategies of new history writing in three historical plays, Generation After Generation(2000) by Park Geunhyung, The Mercenaries(2000) by Park Sujin, and Chosun Detective Hong Yunshik(2007) by Sung Giwoong. In Generation After Generation, the author adopts a plot of starting with the present and tracing back to the past, breaking down the myth of racially homogeneous nation. At the same time, he discloses that the colonial history is not just by the oppressive force of Japan but also by the voluntary cooperation of Korean people. That is, we are also accountable for the colonial history of the nation. The Mercenaries contrasts the independence movement during the colonial period against the modern history developed after Liberation, thus highlighting the still continuing coloniality, namely post-colonial present. The past is presented as the "phantom of history" making its appearance according to the request of the present hoping for salvation. The author politicizes history and grants political wishes to history by summoning the history by personal memories such as fictional diaries and letters with Messiah-like images opposed to the present of collapse and catastrophe. In Chosun Detective Hong Yunshik, the author makes an attempt at the microscopic reproduction of daily life by approaching the 1930s as the modern period when capitalist daily life started to take root. The lists of signs comprising daily life in colonial Gyeongseong are divided between civilization and savagery and between modern and premodern. With the progress of narrative, however, they become mixed together and reversed in the representation system in which the latter overwhelms the former.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.43-55
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• 2019

Smart phone based navigation applications are very useful in everyday life. Cost-effective and user friendly navigation can be provided to the user by many applications available in market. Using the Smart phone these navigation applications provide accurate navigation for outdoor locations. But providing an accurate navigation underground space such as subway station is still a challenge. It is hence more convenient and appropriate for mobility services if the visitors could simply view the guidance of the subway station on their mobile phone, wherever and whenever it is needed. This study develops a algorithm for indoor navigation with the help of Augmented Reality(AR) and QR marker code from the entrance to the train platform for users. This indoor navigation uses AR and QR maker codes for two purposes: to provide the user link to the subway station location and to provide the current guidance details to the user. This Smart phone algorithm that uses a smart phone optical tool to decode the QR marker to determine the location information and provide guidance to the AR without indoor Maps. This algorithm also provides a module to guide mobility vulnerable to the Barrier Free route to destination.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.169-180
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• 2018

White light-emitting diodes (LEDs) are more economical than fluorescent lights, and provide high brightness, a high lifetime expectancy, and greater durability. As LEDs are closely connected with people's daily lives, dimming control of LED is an important component in providing energy savings and improving quality of life. In visible light communications systems using these LEDs, multiple input multiple output (MIMO) technology has attracted a lot of attention, in that it can attain the channel capacity in proportion to the number of antennas. This paper analyzes the power performance of three kinds of modulation in visible light communications (VLC) systems applied space-time block code (STBC) techniques. The modulation schemes are return-to-zero on-off keying (RZ-OOK), variable pulse position modulation (VPPM), and overlapping pulse position modulation (OPPM), and dimming control was applied. The power requirements and power consumption were used as metrics to compare the power efficiency in $2{\times}2$ STBC-VLC environments under the three kinds of modulation. We confirm that dimming control affects the communications performance of each modulation scheme. VPPM showed greater consumption among the three modulations, and OPPM showed energy savings comparable to VPPM.

• The Korean Journal of Archival Studies
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• no.46
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• pp.233-286
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• 2015

A Collection Policy provides a direction to an archive, but also provides a foundation for developing practical measures of planning and collecting process. In terms of a Collection Policy, it enables detail collection as regulations or codes cannot be as defined as the level of collection, thus, it allows systematic and strategic approaches in collecting former presidents' records. In the case of United States, where the same presidential system exists as South Korea, although the individual Presidential Libraries and Museums have different periods of collections, the Collection Policy was implement a half century ago that is used as a foundation data for record collection. However, the Presidential Archives in South Korea do not have a Collection Policy implemented that the collection is based on 'collection regulations' and 'collection plans.' In the comparison of the Collection Policy at the Presidential Libraries and Museums in the United States and the "collection regulation" and "collection plan" at the Presidential Archives in South Korea, it shows that while the Presidential Libraries and Museums' Collection Policy applies the characteristics of individual presidents that the collection comprises the records from more than the appointed period that it includes various personal records of relating figures, events, regions, and even personal interest; the records are written in detail to the detailed scale and procedure. On the other hand, the Presidential Archives in South Korea, the records collected based on 'collection regulations' and 'collection plans' do not sufficiently apply the individual features of the former presidents that the collections remain as general and unclear. This is due to the absence of a Collection Policy that systemizes and sustains professionalism and consistency of collection plans and procedures. Hence, this study is conducted to propose collection policy implementation measures by analyzing the Collection Policy of the Presidential Libraries and Museums in the United States and identifying implications for applying individual president characteristics.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.1
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• pp.29-38
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• 2019

In order to investigate the behavioral characteristics of Pacific cod (Gadus macrocephalus) released at the entrance of Jinhae Bay, Korea, the direction and range of movement, swimming speed of the fish were measured with an acoustic telemetry techniques in winter, 2015. Three wild Pacific codes WC1 to WC3 (total length 66.0, 75.0, 76.0 cm; body weight 2.84, 2.79, 3.47 kg, respectively) were tagged with the acoustic transmitter. WC1 tagged with an acoustic transmitter internally by surgical method, WC2 and WC3, externally with the acoustic data logger and a micro data logger for recording audible sound waves including timer release unit. The movement routes of the tagged fish were measured more than five hours using VR100 receiver and a directional hydrophone. The directionality of the fish movement was tested by Rayleigh's z-Test, the statistical analysis, and a statistical program SPSS. Three tagged fishes were individually released on the sea surface around the entrance to the Jinhae Bay on 10 to 24 January 2015. WC1 moved about 13.32 km with average swimming speed of 0.63 m/s for six hours. The average swimming depth and water depth of the seabed on the route of WC1 were 7.2 and 32.9 m, respectively. The movement range of WC2 and WC3 were 7.95 and 11.06 km, approximately, with average swimming speed of 0.44 and 0.58 m/s for 5.1 and 5.3 hours, respectively. The average swimming depth of WC2 and WC3 were 18.7 and 5.0 m, and the water depth on the route, 34.4 and 29.8 m, respectively. Three fishes WC1 to WC3 were shown significant directionality in the movement (p < 0.05). Movement mean angles of WC1 to WC3 were 77.7, 76.3 and $88.1^{\circ}$, respectively. There was no significant correlation between the movement direction of fish (WC1 and WC2) and the tidal currents during the experimental period (p >= 0.05). Consequently, three tagged fishes were commonly moved toward outside of the entrance and headed for eastward of the Korean Peninsula, approximately, after release. It may estimate positively that the tidal current speed may affect to the swimming speed of the Pacific cod during the spring tide than the neap tide.

• Journal of Coastal Disaster Prevention
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• v.5 no.4
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• pp.163-172
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• 2018

To propose the design technique and the execution manual of the LWFS(Lightweight Foamed Soil) method using dredged soil, the operation system for the test-bed integrated management, and to establish an amendment for the domestic quantity per unit and specifications, and a strategy for its internationalization. In order to utilize the dredged soil from the coastal area as a construction material, we constructed the embankment with LWFS on soft ground and monitored its behavior. As a result, it can be expected that the use of LWFS as an embankment material on the soft ground can improve the economic efficiency by reducing the depth and period of soil improvement as well as the uses of nearby dredged soil. To verify the utilization of the dredged soil as a material for light-weighted roadbed, soft ground and foundation ground, and surface processing, perform an experimental construction for practical structures and analyze the behavior. It is expected to be able to improve the soft ground with dredged soil and develop technique codes and manuals of the dredged soil reclamation by constructing a test-bed in the same size of the fields, and establish the criteria and manual of effective dredged soil reclamation for practical use. The application technology of the dredged soil reclamation during harbor constructions and dredged soil reclamation constructions can be reflected during the working design stage. By using the materials immediately that occur from the reclamation during harbor and background land developments, the development time will decrease and an increase of economic feasibility will happen. It is expected to be able to apply the improved soil at dredged soil reclamation, harbor and shore protection construction, dredged soil purification projects etc. Future-work for develop the design criteria and guideline for the technology of field application of dredged soil reclamation is that review the proposed test-bed sites, consult with the institutions relevant with the test-bed, establish the space planning of the test-bed, licensing from the institutions relevant with the test-bed, select a test-bed for the dredged soil disposal area.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.499-506
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• 2021

Hackers' cyber attack techniques are becoming more sophisticated and diversified, with a form of attack that has never been seen before. In terms of information security vulnerability standard code (CVE), about 90,000 new codes were registered from 2015 to 2020. This indicates that security threats are increasing rapidly. When new security vulnerabilities occur, damage should be minimized by preparing countermeasures for them, but in many cases, companies are insufficient to cover the security management level and response system with a limited security IT budget. The reason is that it takes about a month for analysts to discover vulnerabilities through manual analysis, prepare countermeasures through security equipment, and patch security vulnerabilities. In the case of the public sector, the National Cyber Safety Center distributes and manages security operation policies in a batch. However, it is not easy to accept the security policy according to the characteristics of the manufacturer, and it takes about 3 weeks or more to verify the traffic for each section. In addition, when abnormal traffic inflow occurs, countermeasures such as detection and detection of infringement attacks through vulnerability analysis must be prepared, but there are limitations in response due to the absence of specialized security experts. In this paper, we proposed a method of using the security policy information sharing site "snort.org" to prepare effective countermeasures against new security vulnerability attacks.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.183-190
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• 2021

The purpose of this study was to determine the change trend of emergency department visits among elderly patients with chronic diseases. Using the National Emergency Department Information System data, from January 1, 2014 to December 31, 2019, the selected patient data were evaluated for the emergency department discharge main diagnosis codes for eight chronic diseases. The incidence of elderly chronic diseases, emergency department visits, and admission rates were analyzed. Since 2014, there has been a consistent increase in the number of elderly patients visiting the emergency department, especially among those aged over 85 years. The number of emergency department visits among the elderly chronically ill patients also increased, with a significant increase in ischemic heart disease and arthrosis cases. Furthermore, there was a significant difference in the number of chronically ill patients in each year from 2014-2019 (P<0.001). With respect to the trend of admission rates to the emergency department by chronic disease, most diseases showed an increasing trend (P<0.001). however, hyperlipidemia showed a continuous decreasing trend in all age groups since 2014 (P<0.001). Among the elderly chronically ill patients, a greater increase in the admission rate following emergency department visits was noted in those over 85 years of age, with a significant difference in all diseases, except for hyperlipidemia, hypertension, and tuberculosis (P<0.001). As the aging population grows, the emergency department admission rates among the elderly chronically ill patients will rise rapidly. This could create issues with respect to the use and consumption of emergency medical resources. Hence, it is necessary to manage chronic diseases effectively in the elderly.