• Journal of Astronomy and Space Sciences
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• v.26 no.1
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• pp.99-110
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• 2009

The main purpose of the current research is to developments a real-time Hardware In-the-Loop (HIL) simulation testbed for the satellite formation flying navigation and orbit control. The HIL simulation testbed is integrated for demonstrations and evaluations of navigation and orbit control algorithms. The HIL simulation testbed is composed of Environment computer, GPS simulator, Flight computer and Visualization computer system. GPS measurements are generated by a SPIRENT GSS6560 multi-channel RF simulator to produce pseudorange, carrier phase measurements. The measurement date are transferred to Satrec Intiative space borne GPS receiver and exchanged by the flight computer system and subsequently processed in a navigation filter to generate relative or absolute state estimates. These results are fed into control algorithm to generate orbit controls required to maintain the formation. These maneuvers are informed to environment computer system to build a close simulation loop. In this paper, the overall design of the HIL simulation testbed for the satellite formation flying navigation and control is presented. Each component of the testbed is then described. Finally, a LEO formation navigation and control simulation is demonstrated by using virtual scenario.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.489-492
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• 2006

Red tide occurred sporadically in early 90s. But It is happening extensively by global warming. So, Airline observation, Red tide buoy development, and Red tide alarm system research is progressing for monitor ring. However, study to early forecast red tide and red tide alarm system did not exist hard. This paper proposed development that design and implementation red tide database of using wireless sensor network. There are GPS, Water Temperature sensor, Oxygen sensor, and Turbidity sensor in each node. And data is stored to red tide database through Ad-hoc network. This data is integrated and analyzed. So, forecast red tide. And red tide database has red tide data that happen at past. This is utilized to comparative analysis data for red tide estimate. Main screen displays position of node and measured value in electron map. Much studies must be backed for this a study. But I think that contribute to analyze red tide data by red tide database construction.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.1
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• pp.9-21
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• 2020

The proper operation and safety management of water and wastewater treatment systems are essential for providing stable water service to the public. However, various natural disasters including floods, large storms, volcano eruptions and earthquakes threaten public water services by causing serious damage to water and wastewater treatment plants and pipeline systems. Korea is known as a country that is relatively safe from earthquakes, but the recent increase in the frequency of earthquakes has increased the need for a proper earthquake management system. Interest in research and the establishment of legal regulations has increased, especially since the large earthquake in Gyeongju in 2016. Currently, earthquakes in Korea are managed by legal regulations and guidelines integrated with other disasters such as floods and large storms. The legal system has long been controlled and relatively well managed, but technical research has made limited progress since it was considered in the past that Korea is safe from earthquake damage. Various technologies, including seismic design and earthquake forecasting, are required to minimize possible damages from earthquakes, so proper research is essential. This paper reviews the current state of technology development and legal management systems to prevent damages and restore water and wastewater treatment systems after earthquakes in Korea and other countries. High technologies such as unmanned aerial vehicles, wireless networks and real-time monitoring systems are already being applied to water and wastewater treatment processes, and to further establish the optimal system for earthquake response in water and wastewater treatment facilities, continuous research in connection with the Fourth Industrial Revolution, including information and communications technologies, is essential.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.4
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• pp.232-243
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• 2002

There are many methods for improving TLB (translation lookaside buffer) performance, such as increasing the number of entry in TLB, supporting large page or multiple page sizes. The best way is to support multiple page sizes, but any operating system doesn't support multiple page sizes in user mode. So, we propose the new structure of TLB supporting two pages to obtain the effect of multiple page sizes with high performance and at low cost without operating system support. we propose a new TLB structure supporting two page sizes dynamically and selectively for high performance and low cost design without any operating system support. For high performance, a promotion-TLB is designed by supporting two page sizes. Also in order to attain low power consumption, a banked-TLB is constructed by dividing one fully associative TLB space into two sub-fully associative TLBs. These two banked-TLB structures are integrated into a banked-promotion TLB as a low power and high performance TLB structure for embedded processors. According to the results of comparison and analysis, a similar performance can be achieved by using fewer TLB entries and also power consumption can be reduced by around 50% comparing with the fully associative TLB.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.230-231
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• 2019

This study is a development on condition based maintenance(CBM) technology which is a core item of future autonomous ships. It is developing to design & installation of condition monitoring system and acquisition & processing of data from ongoing ships for fault prediction & prognosis of engine in operation. The ultimate goal of this study is to develop a predicts and decision support software for marine engine faults. To do this, the FMEA and fault tree analysis of the main engine should be accompanied by the analysis of classification of system, identification of the components, the type of faults, and the cause and phenomenon of the failure. Finally, the CBM system solution software could predict and diagnose the failure of main engine through integrated analysis for bid-data of ongoing ships and engineering knowledge. Through this study, it is possible to pro-actively cope with abnormal signals of engine and to manage efficiently, and as a result, expected that marine accident and ship operation loss during navigation will be prevented in advance.

• Journal of the Korean Geotechnical Society
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• v.25 no.1
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• pp.5-19
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• 2009

Most of earthquake-induced geotechnical hazards have been caused by the site effects relating to the amplification of ground motion, which is strongly influenced by the local geologic conditions such as soil thickness or bedrock depth and soil stiffness. In this study, an integrated GIS-based information system for geotechnical data, called geotechnical information system (GTIS), was constructed to establish a regional counterplan against earthquake-induced hazards at an urban area of Daejeon, which is represented as a hub of research and development in Korea. To build the GTIS for the area concerned, pre-existing geotechnical data collections were performed across the extended area including the study area and site visits were additionally carried out to acquire surface geo-knowledge data. For practical application of the GTIS used to estimate the site effects at the area concerned, seismic zoning map of the site period was created and presented as regional synthetic strategy for earthquake-induced hazards prediction. In addition, seismic zonation for site classification according to the spatial distribution of the site period was also performed to determine the site amplification coefficients for seismic design and seismic performance evaluation at any site in the study area. Based on this case study on seismic zonations in Daejeon, it was verified that the GIS-based GTIS was very useful for the regional prediction of seismic hazards and also the decision support for seismic hazard mitigation.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.255-277
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• 2011

Product Service System(PSS), which is an integrated combination of product and service, provides new value to customer and makes companies sustainable as well. The objective of this paper draws Critical Successful Factors(CSF) of PSS through multiple case study. First, we review various concepts and types in PSS and Platform business literature currently available on this topic. Second, after investigating various cases with the characteristics of PSS and platform business, we select four cases of 'iPod of Apple', 'Kindle of Amazon', 'Zune of Microsoft', and 'e-book reader of Sony'. Then, the four cases are categorized as successful and failed cases according to criteria of case selection and PSS classification. We consider two methodologies for the case selection, i.e., 'Strategies for the Selection of Samples and Cases' proposed by Bent(2006) and the seven case selection procedures proposed by Jason and John(2008). For case selection, 'Stratified sample and Paradigmatic cases' is adopted as one of several options for sampling. Then, we use the seven case selection procedures such as 'typical', 'diverse', 'extreme', 'deviant', 'influential', 'most-similar', and 'mostdifferent' and among them only three procedures of 'diverse', 'most?similar', and 'most-different' are applied for the case selection. For PSS classification, the eight PSS types, suggested by Tukker(2004), of 'product related', 'advice and consulancy', 'product lease', 'product renting/sharing', 'product pooling', 'activity management', 'pay per service unit', 'functional result' are utilized. We categorize the four selected cases as a product oriented group because the cases not only sell a product, but also offer service needed during the use phase of the product. Then, we analyze the four cases by using cross-case pattern that Eisenhardt(1991) suggested. Eisenhardt(1991) argued that three processes are required for avoiding reaching premature or even false conclusion. The fist step includes selecting categories of dimensions and finding within-group similarities coupled with intergroup difference. In the second process, pairs of cases are selected and listed. The second step forces researchers to find the subtle similarities and differences between cases. The third process is to divide the data by data source. The result of cross-case pattern indicates that the similarities of iPod and Kindle as successful cases are convenient user interface, successful plarform strategy, and rich contents. The differences between the successful cases are that, wheares iPod has been recognized as the culture code, Kindle has implemented a low price as its main strategy. Meanwhile, the similarities of Zune and PRS series as failed cases are lack of sufficient applications and contents. The differences between the failed cases are that, wheares Zune adopted an undifferentiated strategy, PRS series conducted high-price strategy. From the analysis of the cases, we generate three hypotheses. The first hypothesis assumes that a successful PSS system requires convenient user interface. The second hypothesis assumes that a successful PSS system requires a reciprocal(win/win) business model. The third hypothesis assumes that a successful PSS system requires sufficient quantities of applications and contents. To verify the hypotheses, we uses the cross-matching (or pattern matching) methodology. The methodology matches three key words (user interface, reciprocal business model, contents) of the hypotheses to the previous papers related to PSS, digital contents, and Information System (IS). Finally, this paper suggests the three implications from analyzed results. A successful PSS system needs to provide differentiated value for customers such as convenient user interface, e.g., the simple design of iTunes (iPod) and the provision of connection to Kindle Store without any charge. A successful PSS system also requires a mutually benefitable business model as Apple and Amazon implement a policy that provides a reasonable proft sharing for third party. A successful PSS system requires sufficient quantities of applications and contents.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.422-434
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• 2020

This study aims to analyze the types of college admission that should be strengthened or reflected in universities and to suggest the direction of entrance examination by identifying the actual implementation of the literature-science integrated 2015 revised national curriculum. In order to do so, in-depth interviews on the current state were executed to five curriculum experts. As a result of the interview, it was found that the introduction and adoption of clear admission types look into the inner side of high school life are necessary. Also, it is required to establish specific criteria for student selection expand in-depth interviews related to learning activities in high school, strengthen evaluation competence of admission staffs and recruit more evaluation personnel. In addition, in order to revitalize the 2015 revised curriculum, it is necessary to evaluate how many subjects, especially in career-related subjects, students have taken in order to expand the school record-focused system. For this, it is required to extract evaluation elements and criteria of universities that can grasp continuous and active role performance, and to design a typical design that can objectively judge them. This study can contribute to the settlement of the selection process that can revitalize public education. And it is expected that the selection of the talents desired by the university will be used as a possible basic data.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.14-22
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• 2012

In regards to museum planning of Korea, it is mainly depending on overseas cases and relevant domestic books without systematic guideline on the space programme in a museum. Therefore, it is urgently required to establish systematic index as it is incapable of proposing detailed analysis and index in accordance with each element. As various problems occurred due to above reason, total floor area of museum was divided by the area of exhibition section, storage section, research section, and public & other area and its ratio was calculated for statistics targeting 614 museums built after 1990's when many public museums were built with the settlement of local self-governing system and the type of museums was diversified. It was again classified into 4 elements of period, region, scale, and type and then the influence of each element on each section of museum was understood through integrated analysis. First, looking into the space programme in regards to total floor area, the floor area ratio of exhibition section, storage section, and research section decreased and the floor area ratio of public & other area increased with the increase in total floor area. It was because not only rest area but also a space to enjoy various cultures, gaining new experience, and accumulate knowledge is located in public & other area. Second, it was revealed that the ratio of exhibition section and storage section has been decreasing since 1990's and ratio of research section and public & other area has been increasing as they can play various roles such as the education and convenience to satisfy cultural desires of visitor in accordance with current trend. Third, it was proved that floor area ratio of exhibition section is lower than storage section in museums located in highly urbanized region. In addition to this, it was revealed that the floor area ratio of research section is in proportion to the population density. As a result of study, significant relation was displayed in scale, era, and region among 4 elements thus it could be utilized as reference for the space programme of domestic museum planning in the future.

• Fire Science and Engineering
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• v.30 no.1
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• pp.138-148
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• 2016

A firefighting simulation was developed in order to assess the physical work capacity of firefighters. The simulation consisted of eight common firefighting tasks, including walking with radiant heat for 3 min while wearing full personal protective equipment (PPE). Nine professional firefighters performed the test a total of three times with a 5 min rest interval between each session. The entire series of tests took approximately 30 min to complete ($381{\pm}30s$). Rectal temperatures were found to increase from $37.4{\pm}0.3^{\circ}C$ to $38.5{\pm}0.4^{\circ}C$, while heart rates were found to increase from $92{\pm}18bpm$ to $185{\pm}13bpm$ during testing. Time to completion of the test drills and non-modified physical fitness values showed a significantly negative correlation (r = -0.728, p < 0.05). Firefighters who had longer periods of firefighting service had longer duration time and also recorded higher scores using an integrated scoring system of time to completion (TTC) and physiological strain index (PhSI). The results indicated that the determination of TTC alone can be a misrepresentation of capability, as it neglects to account for accumulated heat strain. The simulated firefighting test provided a useful insight into physical fitness level, but also the comprehensive work capacity of the firefighters when assessed based on TTC and PhSI.