• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.6
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• pp.455-466
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• 2020

In this study, we built a thermal model for SNIPE 6U nano-satellite which has scientific mission for measuring science data in near Earth space environment and described thermal design based on the thermal model. And the validity of the thermal design was verified through the on-orbit thermal analysis. The thermal design was carried out mainly on the passive thermal control techniques such as surface finishes, insulators, and thermal conductors in consideration of the characteristics of the nano-satellite. However, the components with narrow operating temperature range and directly exposed to the orbital thermal environments, such as a battery and thrusters, are accomodated with heaters to satisfy the temperature requirements. On-orbit thermal analysis conditions are based on the basic orbital conditions of the satellite, and thermal analysis was performed for Normal mode, Launch & Early Orbit Phase (LEOP), Safehold mode, and Maneuver mode which are classified by the power consumption and the attitude of the satellite according to the mission scenario. The analysis results for each mode confirmed that every component satisfies the temperature requirement. In addition, the heater capacity and duty cycle of the battery and thruster were calculated through the analysis results of the Safehold mode.

• Journal of Life Science
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• v.30 no.9
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• pp.813-818
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• 2020

The archaeal clusters of orthologous genes (arCOG) algorithm, which identifies common genes among archaebacterial genomes, was used to identify conservative genes among 168 archaebacterial strains. The numbers of conserved orthologs were 14, 10, 9, and 8 arCOGs in 168, 167, 166, and 165 strains, respectively. Among 41 conserved arCOGs, 13 were related to function J (translation, ribosomal structure, and biogenesis), and 10 were related to function L (replication, recombination, and repair). Among the 14 conserved arCOGs in all 168 strains, 6 arCOGs of tRNA synthetase comprised the highest proportion. Of the remaining 8 arCOGs, 2 are involved in reactions with ribosomes, 2 for tRNA synthesis, 2 for DNA replication, and 2 for transcription. These results showed the importance of protein expression in archaea. For the classes or orders having 3 or more members, genomic analysis was performed by averaging the distance values of the conservative arCOGs. Classes Archaeoglobi and Thermoplasmata of the phylum Euryarchaeota showed the lowest and the highest average of distance value, respectively. This study can provides data necessary for basic scientific research and the development of antibacterial agents and tumor control.

• Journal of Distribution Science
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• v.11 no.8
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• pp.5-14
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• 2013

Purpose - We live in a world of constant change and competition. Many airports have specific competitiveness goals and strategies for achieving and maintaining them. The global economic recession, financial crises, and rising oil prices have resulted in an increasingly important role for facility investment and renewal and the implementation of appropriate policies in ensuring the competitive advantage for airports. It is thus important to analyze the factors that enhance efficiency and productivity for an airport. This study aims to determine the efficiency levels of 20 major airports in East Asia, Europe, and North America. Further, this study also suggests suitable policies and strategies for their development. Research design, data, and methodology - This paper employs the DEA-CCR, DEA-BCC, and DEA-Malmquist production index analysis models to determine airport efficiency. The study uses data on the efficiency and productivity of the world's leading airports between 2006 and 2010. The input variables include the airport size, the number of runways, the size of passenger terminals, and the size of cargo terminals. The output variables include the annual number of passengers and the annual cargo volume. The study uses basic data from the 2010 World Airport Traffic Report (ACI). The world's top 20 airports (as rated by the ACI report) are investigated. The study uses the expanded DEA Model and the Super Efficiency Model to identify the most effective airports among the top 20. The Malmquist productivity index analysis is used to measure airport effectiveness. Results - This study analyzes longitudinal and cross-sectional data on the world's top 20 airports covering 2006 to 2010. A CCR analysis shows that the most efficient airports in 2010 were Gatwick Airport (LGW), Zurich Airport (ZRH), Vienna Airport (VIE), Leonardo da Vinci Fiumicino Airport (FCO), Los Angeles International Airport (LAX), Seattle-Tacoma Airport (SEA), San Francisco Airport (SFO), HongKong Airport (HKG), Beijing Capital International Airport (PEK), and Shanghai Pudong Airport (PVG). We find that changes in airport productivity are affected more by technical factors than by airport efficiency. Conclusions - Based on the study results, we offer four airport development proposals. First, a benchmark airport needs to be identified. Second, inefficiency must be reduced and high-cost factors need to be managed. Third, airport operations should be enhanced through technical innovation. Finally, scientific demand forecasting and facility preparation must become the focus of attention. This paper has some limitations. Because the Malmquist productivity index is based on the hypothesis of the, the identified production change could be over- or under-estimated. Further, as DEA estimates the relative efficiency. It also cannot generalize to include all airport conditions because the variables are limited. To measure airport productivity more accurately, other input variables and environmental variables such as financial and policy factors should be included.

• The Korean Nurse
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• v.29 no.3
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• pp.36-48
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• 1990

This study was attempted to provide us with basic information on how to improve understanding with patients for operation, and to offer then better nursing and treatment. This kind of study will help scientific application to nursing practice and operating room. The data was collected by interviewing 29 patients who underwent the elective surgery under the general anesthesia at Y hospital in Seoul. The interview ran from October 15 to December 15, 1989. The research instrument was a anxiety measurement device (SAAI) originally developed by Spielberger, et al and modified by Jung-Tack Kim. 1. Hypothesis Testing Hypothesis one was that there would be a difference in state anxiety level according to a time difference in watiting for operation. This hypothesis was rejected(state.anxiety level one hour before operation P>.05, r-.747, State anxiety level half an hour before operation P>.05, r-.1550, state anxiety level just before operation, P>.05, r=.1099). However, state anxiety, evel appeared to be associated with a longer watiting period, like one day before operation (P<.05, r-.4628). Hypothesis two was that there would be a difference according to state anxiety level of patients for operation. This was rejected. (Change of blood perssure in systolie P>.05 r=.1082, Change of blood pressure in diastolic P>.05, r=.088, Change of pulse rate, P>.05, r-1.909) 2. Examining trait anxiety and state anxiety levels, the average level of trait anxiety was 42.034, and the average level of state anxiety one day before operation was 43,000. The average level of state anxiety was averaged 42.356 in a waiting room for operation. 3. Examining the state anxiety level by time period, the one hour before was 42.379 the level half an hour before 42.276, and the level just before operation 42.414. The low level of state anxiety was due to the fact that premedication was not eliminated. 4. Age and time period like one day before operation was related to state anxiety level (F=5.271, P<.0.01) and blood pressure in waiting room for operation. That is, state anxiety level and blood pressure of patients one day before operation appeared high. Sex was relation to changes of blood pressure ; the blood pressure of male patients appeard higer than of female patients. A marital status was also related anxiety level one hour before operation the married patient for operation showed a higher state anxiety level than that of the unmarried patient for operation. Education was similarily related to trait anxiety level in which highly educated patients show lower levels of trait anxiety than poorly educated ones. Motive for hospitalization was related to state anxiety level for patient one hour before operation (F=6.464, P<.05) likewise, patients who are supposed to undergo operation hastily showed higher levels of anxiety than patients who expect elective surgeries.

• Conservation Science in Museum
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• v.22
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• pp.53-68
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• 2019

Two lime-soil mixture barrier tombs were excavated from the tomb complex of the Woo Family of the Danyang Wu clan dating to the Joseon dynasty in Godeung-dong, Seongnam-si, Gyeonggi-do. Relevant records offer information for more precisely dating these tombs and identifying their occupants. Tomb No. 4, in which a married couple was interred, has a corbeled square ceiling and inscriptions and paintings on its outer walls. The conservation treatment and an infrared inspection revealed that they were intended to express mourning. Tomb No. 6 has a corbeled rectangular ceiling and a single individual interred within. As the basic structure of the tomb was partially damaged in the process of disassembling it while moving the burial site, it was planned to exhibit the tomb outdoors after the remains and relics are collected. However, as the conservation treatment revealed the presence of funeral fans and pitch, and since the remaining structure clearly demonstrates the features of lime-soil mixture barrier tombs from the Joseon dynasty, the plan was changed following a meeting of an advisory council that decided in favor of presenting the tomb indoors. According to the analysis, the pitch is assumed to be resin of a rather low purity due to the immixture of foreign substances. The two tombs are expected to serve as important materials for related research, such as changes by period in the forms of Joseon-era tombs.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.209-219
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• 2016

The survey was conducted to investigate biomass and distribution of fisheries resources using a quantitative echo sounder and a fixed gillnet around Marado coast of Jeju to obtain the scientific basic data for dispute resolution with a large purse seine fishery and coastal fishing and policy establishment of reasonable fisheries resources. Hydroacoustic surveys were conducted six times (November 28~29, 2015 (night), February 23~24, 2016 (night) and March 3~4, 2016 (night/day), March 30~31, 2016 (night/day)) using a quantitative echo sounder. The pelagic fish densities were relatively higher around Marado in November 2015, February 2016 and March 3~4, 2016. However, demersal fish densities were relatively higher in Jeju coastal waters on March 30~31, 2016. Catch data using fixed gill net were used to calculate biomass. Based on the hydroacoustic data, fish length-weight function and target strength information of dominant fish, the biomass of fishes were estimated as follow: 5.64 ton CV = 70.2% at night on November 28-29 2015, 7.14 ton CV = 35.8% of pelagic fish and 530.77 ton CV = 34.6% of demersal fishes at night on February 23-24 2016, 2.34 ton CV = 56.7% of pelagic fish and 571.93 ton CV = 40.3% of demersal fish at daytime, 1.39 ton CV = 48.4% of pelagic fish and 194.59 ton CV = 54.3% of demersal fish at night on March 3~4 2016, 0.37 ton CV = 72.9% of pelagic fish and 338.79 ton CV = 99.7% of demersal fish at daytime, 0.24 ton CV = 21.3% of pelagic fish and 68.61 ton CV = 53.8% of demersal fish at night on March 30~31 2016.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.1-11
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• 2015

The needs for ecological engineering, which can design ecosystems that integrate human society and their natural environment for the benefit of both, has increased. The Korean Society of Ecology and Infrastructure Engineering (KSEIE) was established for this purpose and has contributed to the research and development of theories and technologies in related fields. However, the current state of educational services and contents of ecological engineering is still needed to be standardized and systematized. In this paper, we outlined the trends of ecological engineering education at international and domestic levels and proposed a sample services and curriculum, brought from the discussions and suggestions made during the forum, Founding the Education for Ecological Engineering, held by the KSEIE. Education of ecological engineering can nurture people who can design and manage ecosystems for the benefits of human and natural society and can restore ecosystems disturbed artificially. The services and curriculum have to meet and cover the challenges facing the future of ecological engineering; a. the ethical interpretation of the balance between human and nature, b. developing and strengthening its relationship with other scientific disciplines and societies - business, policy, education, and practitioners, c. identify and fuse the key ecological engineering principles into other discipline. We proposed a three layers curriculum system, basic (mathematics, physics, chemistry, biology, etc.), core (ecology, hydrology, engineering, etc.), and advanced subjects. The first two can belong to an undergraduate program and the last two can be put into graduate program. The selection of subjects is according to the purpose and needs of the major.

• Journal of Science Education
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• v.36 no.1
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• pp.35-48
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• 2012

The purpose of this study was to analyze inquiry activities in the middle school science textbooks focused on the unit 'Nutrition of Plants' of the 2007 revision curriculum and the corresponding unit 'The Structure and Function of Plants' of the 7th curriculum in terms of content, process and contexts of inquiries. The average number of the inquiry activities in the unit 'Nutrition of Plants' was 9.2, which was a 3.8 decrease than in the unit 'Structure and Function of Plants'. In the respective of process of the inquiry activities, 'observation' was most prevailing in the basic inquiry process and 'data interpretation' was most prevailing in the integrated inquiry process in both of the units. In the respective of the types and contexts of the inquiry activities, 'experiment/observation' was most prevailing and the percentage of the natural scientific contexts was larger in both of the units. In the unit 'Nutrition of Plants', the components of the integrated inquiry process and the percentage of personal contexts were larger than in the unit 'Structure and Function of Plants'. And simulation activities were newly presented and technical contexts and natural environmental contexts were included in the unit 'Nutrition of Plants'. This study makes a suggestion that a wider variety of inquiry activities should be included when new science textbooks are developed.

• Journal of Internet Computing and Services
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• v.20 no.6
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• pp.85-93
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• 2019

Computational Science and Engineering is a convergence study that understands and solves complex problems such as science, engineering, and social phenomena through modeling using computing resources. Computational science and engineering combines algorithms, computational and informatics, and infrastructure. The importance of computational science is increasing with the improvement of computer performance and the development of large data processing technology. In Korea, Korea Institute of Science and Technology Information (KISTI) has been developing national computational science engineering software and utilization technology by combining basic science and computing technology through EDISON project. The EDISON project builds an open EDISON platform and integrates and services information systems in seven areas of computational science and engineering (computational thermal fluids, nanophysics, computational chemistry, structural dynamics, computational design, and computational medicine). Using this, we have established a web-based curriculum to lay the groundwork for fostering scientific talent and commercializing computational science and engineering software. The purpose of this study is to derive the quality characteristic factors of computational science platform and to empirically examine the effect on user satisfaction. This paper examines how the quality characteristics of information systems, the computational science engineering platform, affect the user satisfaction by modifying the research questions according to the propensity of the computational science platform by referring to the success factors of DeLone and McLean's information system. Based on the results of this study, we will suggest strategic implications for platform improvement by searching the priority of quality characteristics of computational science platform.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.61-77
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• 2005

Statement of problem. The implant prosthesis has been utilized in various clinical cases thanks to its increase in scientific effective application. The relevant implant therapy should have the high success rate in osseointegration, and the implant prosthesis should last for a long period of time without failure. Resorption of the peri-implant alveolar bone is the most frequent and serious problem in implant prosthesis. Excessive concentration of stress from the occlusal force and biopressure around the implant has been known to be the main cause of the bone destruction. Therefore, to decide the location and angulation of the implant is one of the major considering factors for the stress around the implant fixture to be dispersed in the limit of bio-capacity of load support for the successful and long-lasting clinical result. Yet, the detailed mechanism of this phenomenon is not well understood. To some extent, this is related to the paucity of basic science research. Purpose. The purpose of this study is to perform the stress analysis of the implant prosthesis in the partially edentulous mandible according to the different nature locations and angulations using three dimensional finite element method. Material and methods, Three 3.75mm standard implants were placed in the area of first and second bicuspids, and first molar in the mandible Thereafter, implant prostheses were fabricated using UCLA abutments. Five experimental groups were designed as follows : 1) straight placement of three implants, 2) 5$^{\circ}$ buccal and lingual angulation of straightly aligned three implants, 3) 10$^{\circ}$ buccal and lingual angulation of straightly aligned three implants. 4) lingual offset placement of three implants, and 5) buccal offset placement of three implants. Average occlusal force with a variation of perpendicular and 30$^{\circ}$ angulation was applied on the buccal cusp of each implant prosthesis, followed by the measurement of alteration and amount of stress on each configurational implant part and peri-implant bio-structures. The results of this study are extracted from the comparison between the distribution of Von mises stress and the maximum Von mises stress using three dimensional finite element stress analysis for each experimental group. Conclusion. The conclusions were as follows : 1. Providing angulations of the fixture did not help in stress dispersion in the restoration of partially edentulous mandible. 2. It is beneficial to place the fixture in a straight vertical direction, since bio-pressure in the peri-implant bone increases when the fixture is implanted in an angle. 3. It is important to select an appropriate prosthodontic material that prevents fractures, since the bio-pressure is concentrated on the prosthodontic structures when the fixture is implanted in an angle. 4. Offset placement of the fixtures is effective in stress dispersion in the restoration of partially edentulous mandible.