• Journal of Astronomy and Space Sciences
• /
• v.31 no.1
• /
• pp.67-72
• /
• 2014

The next generation small satellite-1 (NEXTSat-1) program has been kicked off in 2012, and it will be launched in 2016 for the science missions and the verification of space core technologies. The payloads for these science missions are the Instrument for the Study of Space Storms (ISSS) and NIR Imaging Spectrometer for Star formation history (NISS). The ISSS and the NISS have been developed by Korea Advanced Institute of Science and Technology (KAIST) and Korea Astronomy and Space science Institute (KASI) respectively. The ISSS detects plasma densities and particle fluxes of 10 MeV energy range near the Earth and the NISS uses spectrometer. In order to verify the spacecraft core technologies in the space, the total of 7 space core technologies (SCT) will be applied to the NEXTSat-1 for space verification and those are under development. Thus, the operation modes for the ISSS and the NISS for space science missions and 7 SCTs for technology missions are analyzed for the required operation time during the NEXTSat-1's mission life time of 2 years. In this paper, the operational concept of the NEXTSat-1's science missions as well as the verification of space core technologies are presented considering constraints of volume, mass, and power after launch.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.4
• /
• pp.1-11
• /
• 1999

Thermal behavior of spacecraft propulsion system utilizing monopropellant hydrazine ($N_2$$H_4$) is addressed in this paper. Thermal control performance to prevent propellant freezing in spacecraft-operational orbit was test-verified under simulated on-orbit environment. The on-orbit environment was thermally achieved in space-simulation chamber and by the absorbed-heat flux method that implements an artificial heating through to the spacecraft bus panels enclosing the propulsion system. Test results obtained in terms of temperature history of propulsion components are presented and reduced into duty cycles of the avionics heaters which are dedicated to thermal control of those components. The duty cycles are subsequently converted into the electrical power required in the operational orbit. Additionally, cyclic temperature of each component, which was made under thermal-balanced condition of spacecraft, is compared to the acceptable design range and justified from the viewpoint of system verification.

• The Journal of Society for e-Business Studies
• /
• v.18 no.2
• /
• pp.191-203
• /
• 2013

Today, information technologies have been applied to operations in container terminals, and it is possible to collect operational log data due to development of equipment and operations technology. Terminal operators are collecting event log data and try to figure out the way of resolving operations problems. Operators want to analyze event logs to determine the causes of the operation problems, but it can hardly be done manually. In this paper, we suggest a formal framework to evaluate performance measures using the collected log data of operations in container terminals. The proposed formal framework supports different container terminal layout, operational processes, and equipment. Our formal framework is composed of specification of terminal layout, log data, workflow, statistics, and report, based on the concept of container handling objects. For validation of our framework, we have implemented a terminal performance analysis system based on the proposed framework.

• Earthquakes and Structures
• /
• v.10 no.3
• /
• pp.523-538
• /
• 2016

Besides their spiritual significance, minarets are humanity's cultural heritage to the future generations due to their historical and architectural attraction. Currently, many historical masonry minarets are damaged and destroyed due to several reasons such as earthquakes and wind. Therefore, safety of these religiously significant buildings needs to be thoroughly investigated. The utmost care must be taken into account while investigating these structures. Our study investigated earthquake behavior of historical masonry minaret of Haci Mahmut Mosque. Destructive and non-destructive tests were carried out to determine earthquake safety of this structure. Brick-stone masonry material properties of structure were determined by accomplishing ultrasonic wave velocity, Schmidt Hammer, uniaxial compression (UAC) and indirect tension (Brazilian) tests. Determined material properties were used in the finite element analysis of the structure. To validate the numerical analysis, Operational Modal Analysis was applied to the structure and dynamic characteristics of the structure were determined. To this end, accelerometers were placed on the structure and vibrations due to environmental effects were followed. Finite element model of the minaret was updated using dynamic characteristics of the structure and the realistic numerical model of the structure was obtained. This numerical model was solved by using earthquake records of Turkey with time history analysis (THA) and the realistic earthquake behavior of the structure was introduced.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.67 no.4
• /
• pp.200-207
• /
• 2018

In recent, KEPCO (Korea Electric Power Corporation) faced difficulties of the DCC (distribution control center) due to the increase of field equipment and operational cost, and aging of operating staffs. In response to these changes in the DCC, KEPCO is trying to change the organization and system of the DCC. In this paper, we present a new attempt to change organization and structure of distribution control center, which was implemented by KEPCO recently. This paper is divided into three major parts. First, to examine the adequacy of the divided basis of current DCCs based on the quantity of installed electrical equipment, we analyzed the correlation between the operational history of the DCCs and the number of equipment. Through the analysis, we confirmed that there is little relationship between the number of equipment and actual workload. Second, we conducted visits and questionnaire surveys of all the DCCs to identify factors affecting the actual workload of distribution operators and then summarized the results. Third, based on this survey, a general formula for analyzing the workload of a DCC was derived, and each DCC's average annual total workload, day/night workload, and required number of personnel were calculated. Through this study, we proposed a more realistic management method of DCCs that can overcome the division criteria based on equipment quantity.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.8
• /
• pp.117-125
• /
• 2009

In this paper, an integrated management system of seismic observatory information based on XML is proposed. The number of organizations which have their own seismic stations eg. KMA, KIGAM etc is increasing since 1998. Related informations such as location, installed instruments. and operational profile are essential for efficient utilization of seismic data. It's not easy to provide the uniform type of information and has limitation to announce the updated information of station rapidly through individual information management system of each organization. In this paper, we propose an integrated management system of seismic observatory information which can support to manage information of their own seismic observatory by a person in charge via Web, to integrate that in nation-wide and to provide that for users. We investigated minimum information of observatory were needed to use seismic data and the analysis result was structured by using XML. The integrated management system consists of the observatory management module. information search module, and the latest information supply module etc. By using proposed system, seismic observatory information of each organization can be managed and be supplied efficiently in nation-wide.

• Structural Monitoring and Maintenance
• /
• v.10 no.1
• /
• pp.87-105
• /
• 2023

Seismic regulations have been updated from time to time to accommodate an increase in seismic hazards. Comparison of seismic fragility of the existing bridges in Indonesia from different historical periods since the era before 1990 will be the basis for seismic assessment of the bridge stock in Indonesia, most of which are located in earthquake-prone areas, especially those built many years ago with outdated regulations. In this study, seismic fragility curves were developed using incremental non-linear time history analysis and more holistically according to the actual strength of concrete and steel material in Indonesia to determine the uncertainty factor of structural capacity, βc. From the research that has been carried out, based on the current seismic load in SNI 2833:2016/Seismic Map 2017 (7% probability of exceedance in 75 years), the performance level of the bridge in the era before SNI 2833:2016 was Operational-Life Safety whereas the performance level of the bridge designed with SNI 2833:2016 was Elastic - Operational. The potential for more severe damage occurs in greater earthquake intensity. Collapse condition occurs at As = F_PGA x PGA value of bridge Era I = 0.93 g; Era II = 1.03 g; Era III = 1.22 g; Era IV = 1.54 g. Furthermore, the fragility analysis was also developed with geometric variations in the same bridge class to see the effect of these variations on the fragility, which is the basis for making bridge risk maps in Indonesia.

• Journal of the Korea Convergence Society
• /
• v.6 no.6
• /
• pp.285-291
• /
• 2015

FTMS, TCS, ITS equipment such as high-pass highway are just a situation that does not lack traceability and passive surveillance is related to fault DB has so far consisted of an integrated operations management to maximize utilization of the facility. In addition, there is no replacement parts are replaced when a failure occurs, increasing the number of parts and repair time I have trouble growing, and becoming a service interruption whenever you replace each time. In this study, proactively manage the failure history of a highway facility ITS tries to preventive maintenance. Therefore, the error history is based on the reliability of the high-pass facilities theory to calculate the reliability of the system through a systematic statistical analysis Operational Availability. The fault number and the time the replacement period through the estimate decreases and can reduce the budget expenses by securing the spare parts quantity, establish a management plan in part by improving the quality of the system through constant preventive maintenance, quality of service at all times It may direct the non-stop operation state of the available state.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.38 no.4
• /
• pp.25-34
• /
• 2010

This study was conducted to develop evaluation indicators to improve athletic performance and operational management of golf courses and the results of the research are as follows. Through theoretical research and a preliminary professional survey, 15 on-going evaluations of golf course composition and operational management and 55 sub-evaluation indices were rejected while 10 on-going evaluations and 52 sub-evaluation indicators were reconfigured as final for environmental-friendliness, level of member services, level of human service of game personnel, difficulties of course, management level of the course, fairness of operational management, accessibility and location characteristic, traditions and ambiance of the golf club, quality of course, and course layout. When analyzing the important decision factors in golf course user preference evaluation indicators, the following contributed in the order of higher to lower contributions: the management level of the course, excellence of the course, level of human services for personnel, course layout and environmental-friendliness. When identifying the path coefficient of golf course evaluation indicators, the curvature of a hole and the length of the course had a causal effect on the 'course layout' section. Tournament facilities and various shot values had a causal relationship with 'excellence of the course', in the order of higher to lower, and convenience of waiting and fair allocation of reservations for 'fairness of operational management'. The history of the golf course and its environmental characteristics, history and culture of the region have relatively higher causal effects on 'traditions of the golf club' and geographical conditions on 'accessibility and location characteristics', pesticide and fertilizer usage and water pollution on 'environmental-friendliness', and member benefit and kindness of employees on 'level of member services'. The kindness and expertise of the game personnel had a relatively higher causal effect on the 'level of human services of game personnel', the location of tenning area, and location of OB and hazards on 'difficulties of course', and rough conditions and obstacles management on 'management level of the course'. There is a need to complete a systematic evaluation index system for golf course user preferences through future studies for a more detailed assessment, as well as a process to verify these evaluation indicators by application to domestic and international golf courses.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.22 no.4
• /
• pp.122-134
• /
• 2009

Purpose: The purpose of this study is to know the blood stasis pattern for the patients who had hysterectomy. Methods: Among the patients who had hysterectomy in the department of obstetrics and gynecology, OO medical center from March 3rd 2009 to October 21st 2009, subjects who met inclusion criteria and submitted appropriate questionnaire. We compared blood stasis score and operational method, age, BMI, past operation history of abdominal and pelvic site, parity, whether adhesiolysis, oriental medicine intervention was done. For statistics, we used independent samples t-test, oneway analysis of variances(ANOVA) and SPSS version 13.0 for windows. Results: Blood stasis score of the subtotal hysterectomy group ($44.43{\pm}15.01$) is higher than that of the total hysterectomy group($39.04{\pm}12.46$). Blood stasis score under the age 40($51.88{\pm}12.68$) is higher than 40-49 age patients($40.34{\pm}14.24$) and over the age 50 patients($41.62{\pm}13.46$). There is no statistically significant difference between laparoscopic and abdominal trial, whether adhesiolysis, oriental medicine intervention was done, BMI, past operation history abdominal and pelvic site, parity, chief complaint before hysterectomy, oriental medicine intervention. Conclusion: Through the results showed, when traditional Korean medical doctors use static blood medication, history of hysterectomy and age should be considered as the history of subtotal hysterectomy and younger age tend to have a higher rate of a blood stasis pattern. We need a further study to develop blood stasis indicators with a validated questionnaire, and more subjects involved at multiple institutions.