• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.1
• /
• pp.111-116
• /
• 2010

To improve occupants' safety in an emergency, crashworthy design is necessary to rotorcraft design and development. Especially, landing gear has the important role for crashworthy design because landing gear absorbs relatively large energy for the crash landing. In addition, military specifications require failure of landing gear shall not increase danger to any occupants by penetration of the airframe. To meet the specification requirements, crashworthiness device like failure mechanism should be prepared so that landing gear is collapsed safely and doesn't penetrate the airframe. In this study, design and design development test of the failure mechanism which is necessary for the rotorcraft landing gear was performed. First, collapse scenario was determined for the landing gear not to penetrate the airframe. Then, the failure pin which is the most important part of the failure mechanism was designed with 2 strength range in order to meet design criteria. Finally, design of the failure mechanism was verified successfully by design development test.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.1 s.17
• /
• pp.71-79
• /
• 2004

In the stage of feasibility study of urban rehabilitation projects, the precise forecast of physical and environmental changes has great influence on the further transaction of the projects. However, various important decision makings are made by the experience and intuition of the person-in-charge in practice without the process and method for systematic and quantitative analysis. In spite of various qualitative influent factors on the projects, the feasibility studies are made by the result of economic analysis only, which often lead the projects to the crucial deficit. The main reasons of such a mal-functional transaction are due to the absence of the reasonal procedure of feasibility study and decision making reflecting the characteristics of urban rehabilitation projects. The objective of this paper is to propose feasibility study processes and decision making methods in relation to various influent factors on urban rehabilitation projects in the initial stage. The goal and process of every analysis stage and the pertinent factors and decision makings are analyzed and proposed through the survey of current research, a case study, interview with the professionals. The processes and methods are well applied to improve current problems of feasibility study of urban rehabilitation projects. In addition, the establishment of the analysis goal at three principal stage and a series of reasonable decision makings with pertinent factors to each stage will lead the project to more successful result than ever.

• The Journal of Korean Institute for Practical Engineering Education
• /
• v.3 no.2
• /
• pp.18-26
• /
• 2011

Computational chemistry is one of the chemistry fields that deals with the theoretical chemistry problem using computer calculations and can be described as the chemistry lab moved on computer space. In line with recent enhancement of processing capability of computers, utilization of high performance computer cannot be overemphasized in the field of computational chemistry in performing complex calculation of huge molecular structure and simulation. While they have to use commands and consoles for high performance computer to execute complex calculation of huge molecular structure and simulation, most of students in natural science and engineering, who are not experts in computer technically, are likely to be unaware of UNIX. Under the circumstances, web-based educational support system for computational chemistry is needed to enable them to practice computational chemistry, even not knowing UNIX command. In this study, e-Chem, one of such educational support systems, is developed by using Liferay portal platform, which is a Java open source more oriented to standard and outstanding in its content management and collaboration function than other web portals. By using this system, even students who are not familiar with computer, are expected to take part in lab classes and save time learning Unix command and also enhance the learning efficiency by using familiar interface.

• The Journal of the Korea Contents Association
• /
• v.14 no.5
• /
• pp.166-178
• /
• 2014

In this study, to know the influence of pro-social behavior by service orientation of care facility for the elderly, made a research from 80 care facility for the elderly of about 400 professor employees with visiting them and by the mail. survey was from 302 senior citizens by 61 facilities, and the final analysis was helped by 297 professor employees. First, as analysis from the standard of prime variable, it showed 3.84 of relatively high marked from the who have had aware of the level of pro-social behavior. overall, standard of service orientation shown 3.69 out of 5 which is also relatively high. Looking at the sub- dimensions of service-oriented leadership performance has shown 4.13 points out of 5, 3.78 points out of 5 on buildup the systems, management of human resource orientation shown 3.5 points out of 5 and attitude of services shown 3.36 points out of 5. In general, the service has showed up higher points on the overall. Second, by the analysis from the regression analysis, fulfillment of leadership (B=.004, P=.938), attitude of service (B=.031, P=.476), management of human resource (B=.147, P=.003), system build up (B=.175, P=.001) were made meaningfully influenced on pro-social behavior. Especially, the sub- dimensions of human resource management and the system buildup had a importantly major role for influencing on pro-social behavior. Based on this, in this study, care facility for the elderly professionals the ability to manage human resources programs and services to improve the efficiency of the system was proposed for building plans.

• Journal of Science Education
• /
• v.44 no.1
• /
• pp.61-73
• /
• 2020

Teachers are the most important factor contributing to determining the quality of education. Therefore, the quality of teachers should be improved to enhance the quality of education. Teacher's competencies are defined as the skills required for teaching profession, that is, the ability to perform not only in teaching activities, but also in guidance and class management. The purpose of this study is to analyze the competencies of science teachers that elementary, middle and high school students want. To this end, 332 elementary, middle and high school students were asked to describe their preferred science teacher's competencies and avoiding science teacher's competencies as an open questionnaire. The resulting concepts were analyzed by semantic network analysis (SNA). The results of this study are as follows: 1) The competencies of science teachers that students prefer varied. This suggests that most students think positively about science teachers. In addition, it is possible to show students the positive or preferred competencies of teachers in various ways. 2) The students wanted teachers to explain the theories and concepts related to scientific phenomena through experiments. They also preferred hands-on activities and experience in science class. 3) The students put emphasis on the class-related contents in the competencies of science teachers. Accordingly, the image of science teachers and science itself should be enhanced through the improvement of science teaching methods and positive attitudes toward students. It is expected that further research on the image according to specific teaching methods of science teachers will be conducted based on the findings of this study.

• Journal of Animal Science and Technology
• /
• v.49 no.1
• /
• pp.59-66
• /
• 2007

Sixty-seven Hanwoo calves were allocated into two groups, 27 spring calves (SC) and 40 fall calves (FC) to investigate the effects of calving season on water and nutrient intakes, growth performance and disease occurrence for the nursing and the post-weaning period. Mean DMI of 3 to 4 mo old FC was lower than that of SC due to low temperature in winter for FC. Water intake was higher for FC (birth to 1 mo old) but lower for SC (2 to 4 mo old) than the others. Mean BW did not differ between SC and FC, but average daily gain for over 2 mo old SC were significantly higher than FC. Diarrhea was mainly observed when the calves were before 60 d old; in particular, it occurred more frequently for less than 30 d old FC compared with SC. The present results indicate that calving season may affect water intake, feed intake and growth performance of Hanwoo calves.

• Journal of Satellite, Information and Communications
• /
• v.1 no.2
• /
• pp.95-100
• /
• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 version. Eurostar 3000 EpS is fully autonomous operation in nominal conditions or in the event of a failure and provides a high level of reconfigure capability. This paper introduces the COMS EPS preliminary design result. COMS EPS consists of a battery, a solar arrat wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SDAM(Solar Array Drive Mechanism) and relay and fuse brackets. COMS EPS can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type fo solar cells is selected ad GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated to battery and solar array wing generates a power bus fully regulated at 50 V. Power bus os centralized protection and distribution by relay and fuse brackets. PRU provides power for firing actuarors devices. The solar array wing is rotated by the SADM under control of the attitude orbit control subsystem. The control and monitoring of the EPS, especially of the battery, is performed by the PSR in combination with the on-board software.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.33 no.5
• /
• pp.335-342
• /
• 2015

In this study, data linking module called GeoSWMM was developed using a typical secondary flooding model SWMM in order to improve the accuracy of the input data of SWMM and to map hourly inundation estimation areas that were not represented in the conventional inundation map. GeoSWMM is a data linking module of GIS and SWMM, which can generate a SWMM project file directly from sewer network GIS data. Utilizing the GeoSWMM the project file of SWMM model was constructed in the study area, Seocho 2-dong, Seoul. The actual flooding has occurred September 21, 2010 and the actual rainfall data were used for flood simulation. As a result, the outflow started from 2 PM due to the lack of water flow capacity of the sewage system. Based on the results, hourly inundation estimation maps were produced and compared with flood train map in 2010. The comparison showed about 66% matching in the overlap of inundation areas. By utilizing GeoSWMM that was developed in this study, it is easy to build the sewer network data for SWMM. In addition, the creation of hourly inundation estimation map using SWMM will be much help to flood disaster prevention plan.

• Korean Journal of Cognitive Science
• /
• v.26 no.1
• /
• pp.53-67
• /
• 2015

Metacognitive monitoring refers to high dimensional cognitive activities. Understanding one's own cognitive processes accurately can make effective controls for their performance. Brain area related with metacognition is PFC which is completed the order of late and it can be inferred that monitoring abilities is developing during late adolescent. In this study, we explored the developmental difference in monitoring accuracy between high school students and college students using by measuring JOL(Judgment of Learning). Participants was asked that they study Spanish-Korean word pairs and judge their future performance of memory. In the result, people in both groups thought that they could remember word pairs better than their actual performance. Absolute bias scores which mean the degree to predict their performance apart from true scores showed the interaction between subject groups and task difficulty. Specifically, people judged their learning state quite accurately in easy task condition. However, in difficult task condition, both groups showed inaccuracy for predicting their learning and the magnitude of the degree was bigger in the group of high school students.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.4
• /
• pp.311-318
• /
• 2016

The VTS concept was located as a principal methods of maritime safety administration in world's major harbors and expected to become the pivotal role for the future of the maritime and harbor society with e-Navigation epoch. If recent limelight concept of big-data has been included in aspect of information gathering and analysis with various studies, it's required advanced studies to improve the information analysis capability and application range of the data that can be mining by the VTS. In this study, contrast to other studies that aimed quantitative analysis as communication number, it can be mining the time information and each of the communication VTS for the target vessel, including qualitative analysis, such as the purpose or the type of communication. This comparison across multiple items of the collected information, and presenting the VTS data mining model (VCDF) that can be analyzed for the purpose of analyzing way, type and number of communication by ship's type, also number of violations through VTS communication. First, In Busan port case, it shows frequently information service and shows frequently communicating with particular types of vessels. Second, Passive VTS carried out notwithstanding many kinds of traffic violations due to communication congestion. This arranged information can be used as data for the analysis, as possible the level of traffic for VTSO situational awareness, which pointed to the 'workloads' in 'IALA Guideline' and could be used as a database for future research of e-Navigation.