• Journal of the Korean Society for Railway
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• v.6 no.2
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• pp.122-128
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• 2003

The acceptance test of KTX has been performed in Korea. During the test, lateral vibration of carbody over the accepted value called sway was found. Many activities have been taken to find the cause of the vibration and the counter-measure. KTX has 20 car trainset formation whose trailer cars are linked by articulate bogies. So this study is performed to see the effects of long trainset formation on vehicle dynamics and the train stability by 16 car vehicle model. Firstly the reliable vehicle model which shows well the tendencies appeared in the tests on the high speed test line is required to find the cause of lateral vibration and the countermeasure. Vehicle model was made for the analysis with VAMPIRE. The analysis results show that secondary air spring lateral stiffness is the most significant parameter to cause carbody lateral vibration. Mode analysis results show that the least damped mode shape is similar to the vibration pattern shown in the tests that the amplitude of the motion increases along the train set and decreases in the tail part. The lateral vibration was "appeared at the speed range between 100km/h and 200km/h and disappeared at the low speed and the high speed.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1001-1008
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• 2022

As a part of the Smart Cities Mission, the Government of India in 2015 embarked upon the development of 100 existing cities as smart cities. In this study, the authors selected Ahmedabad city as the smart city development in India and presented project-level elements of the city based on the secondary data availability. At first, the authors focused on peer-reviewed articles, policy documents, and technical reports. Next, the authors collected the secondary data of project-level elements of the Ahmedabad city from the years 2015 to 2019. The findings show no significant improvement in the sewage system and waste collection as compared to the level of investment made in these sectors. The study showed that the water supply system outperformed revenue generation based on the government investment made in that sector. As a lesson learned, these findings indicate that significant improvement should be addressed in sewage management and waste collection. These study findings could help government officials, investors, developers, and city planners in making the appropriate decision before and during smart city execution. The lesson learned from this study could be used as a reference to improve revenue during the future smart city implication.

• International Journal of Computer Science & Network Security
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• v.24 no.7
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• pp.79-86
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• 2024

This research is conducted in order to analyze the student's academic performance at the secondary school level in Sindh province of Pakistan. The study was focused on the students who have passed the Matriculation level recently. The sample of size equal to 1097 secondary level students was randomly selected in a way that from each college roughly up to 150 students took part in the survey. The sample selection was further divided on gender (Male=448, Female=649) and Locale (Urban=456, Rural=641). A survey questionnaire was circulated for data collection. The statistical analysis based on Pearson's Chi-Square and Correlation models were carried out using the collected data. The conclusion was drawn from results that strongly revealed that the student's academic achievement at high school level was highly associated to their parent's educational level and socio-economic background. Therefore, it is strongly recommended that the financial condition of the population must be enhanced by taking suitable measures. The affected students should be awarded adequate financial assistance or scholarships to face such hardships of their learning career. Free laptops, learning materials, books, and stationery should also be provided.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.1
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• pp.33-45
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• 1997

Axisymmetric shear layers around a free jet is forced by co-flowing and counter-flowing secondary jets from/to an annular tube around the jet nozzle. The jet potential core extends far downstream with co-flowing secondary jets due to inhibited vortex developing and pairing. For counter-flowing cases, the axisymmetric shear layer around the jet transits from convective instability to absolute instability for velocity ratios R＝1.3～l.65 for the uniform velocity jets. Consequently, the jet potential core length increases and the turbulence level in the jet core is reduced significantly. The jets are controlled better with extension collars attached to the outer nozzle exit because the annular secondary flow is guided well by the extension collars. For the vectoring of jet, the annular tube around the jet is divided in two parts and the only one part is used for suction. The half suction makes the different shear layer around the jet and vectoring the jet by Coanda effect. The vectoring and turbulent components are varied significantly by the suction ratio. The experiments are carried out to investigate the characteristics of forced free jets using flow visualization, velocity and turbulence measurements.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.4
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• pp.665-672
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• 2013

With the development of advanced processing technology, laser processing systems, which require high-quality precision processing, have attracted considerable attention. Although laser equipment is expensive, it enables quick processing and less deformation of materials. This technology is often applied to secondary batteries, which has thus farinvolved the use of argon tungsten inert gas (TIG) welding. However, the welding characteristics of argon TIG welding are not yet good, and a laser is used for welding to address this problem. In this study, lap-joint welding was conducted, and the desired welding characteristics were obtained when the laser power was 1800W and the laser beam travel speed was 1.8 m/min. Lap-joint welding was conducted on Ni-coated SS41. Two cases were compared. No pores were observed in the Ni-coated SS41 lap-joint welding part, and cracks appeared from the lap-joints. Moreover, the pole rod and tap were welded together in a T-joint form to improve the output of the secondary battery. T-joint laser welding showed better welding characteristics than TIG welding.

• The Journal of Korean Association of Computer Education
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• v.8 no.3
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• pp.61-76
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• 2005

The seventh secondary computer education curriculum is focused on computer literacy education. This computer curriculum is an elective course not a required course and is a part of other specific course. This computer education has problems that it is not consecutive, overlapped with other classes and not systematic. This research analyzes the computer education in Israel, India, and Japan. And it suggests the new secondary school computing education curriculum based on computer educating of Computer Curricula 2001 Computer Science, lEEE Computer Society and ACM has suggested 2001 for computer science education in university, and with a standard of 'A Model Curriculum for K-12 Computer Science', the suggestion for computer-science education for all grade of school.

• Composites Research
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• v.23 no.2
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• pp.31-39
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• 2010

In this paper, composite panels with hat-shaped stiffeners were made using the co-curing, co-bonding and secondary bonding methods. Co-curing is a manufacturing method in which the hat part and the plate are cured simultaneously in a manner that is more cost effective than other methods. Co-bonding is a method in which the stacked prepregs are cured with other cured parts, and secondary bonding is a method in which cured parts are bonded together using an adhesive. A rubber mold was manufactured for co-curing of composite panel with hat-shaped stiffeners, and finite element analyses were done to evaluate the expanding pressure of the rubber mold consistent with the curing temperature. The manufactured panels were also evaluated using a 3-D measurement tester and an ultrasonic tester. Pull-off tests were performed to evaluate their mechanical properties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.705-710
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• 1995

In order to find out the effect of rainfall at harvesting season on germination of malting barley, the seeds sampled from Cheju island and southern part of Korea were examined. The germination rate of seeds from Cheju island where rainfall was frequent at harvesting season, ranged from 46 to 71%, even though disease infection of the seeds was not that serious as would be expected. High sugar content of seed was resulted from the degradation of carbohydrates during the harvest season. From TZ test the rainfall - affected seeds were found to be highly viable but in the state of secondary dormancy. Results of cold germination test showed that the seeds were recovered from the secondary dormancy. Therefore, it was recommended that the seeds affected by the rainfall at harvesting season should be utilized after 12 months when the dormancy period terminated. The germination percent of the seeds was significantly enhanced by prechilling and / or 1 ppm gibberellic acid treatment. Different seed lots showed different rate of germination and the degree of dormancy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.136-140
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• 1992

The purpose of this research is to develop the lithium secondary battery. This paper describes the preparation, electrochemical properties of nontstoichiometric(NS)-$V_6O_{13}$ and characteristics of Li/$V_6O_{13}$ secondary battery. NS-$V_6O_{13}$ was prepared by thermal decomposition of $NH_4VO_3$ under Ar stream of 140ml/min~180ml/min flow rate. And then, this NS-$V_6O_{13}$ was used for cathode active material. Cathode sheet was prepared by compressing the composite of NS-$V_6O_{13}$, acetylene black(A.B) and teflon emulsion (T.E). Characteristics of the test cell are summarised as follows. Oxidation capacity of NS-$V_6O_{13}$ was about 20% less than its reduction capacity. A part of NS-$V_6O_{13}$ cathode active material showed irreversible reaction in early charge-discharge cycle. This phenomena seems to be caused by irreversible incoporation/discoporation of lithium cation to/from NS-$V_6O_{13}$ host. Discharge characteristics curve of Li/$V_6O_{13}$ cell showed 4 potential plateaus. Charge-discharge capacity was declined in the beginning of cycling and slowly increased in company with increasing of coulombic efficiency. Energy density per weight of $V_6O_{13}$ cathode material was as high as 522Wh/kg~765Wh/kg.

• Journal of Korean Home Economics Education Association
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• v.1 no.1
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• pp.63-85
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• 1989

The Change of environment related to human life, science, technology, economics and education level have much effect on home life. Therefore Home Economics Education have to get out of past trite concept that it is only a method to become good housewife and take the role to widen the human life and to grow creative power as a academic part of science. For these, Home Economics should become life education, life education of secondary school has to have relation to lifelong education. To achieve effective result from Home Economics Education, the object, system and methods of Home Economics Education, the object, system and methods of Home Economics Education have to be improved and teaching material has to be studied systematically. As an object of aboves and education planning in clothing is made for deep understanding the study of Home Economics Teaching Material. And to understand the real state, made some questions, had interview with 63-teaching in Kangweon province and show the results. 1) Tab 1~20 are the level of recognition about object, teaching content, time structure of secondary school. The object is recognized as cultural education and basic job education. 2) Tab 21~30 show the real state of textbook and study of it. To take effect from school lecture other teaching material except textbook is required. 3) Tab 31~40 are the result of sewing and handicraft practice. Sewing and handicraft needs much time and almost all time is used in practicing. 4) Tab 42~54 are the planning of textbook study for effective teaching, self-estimation and teaching material making is also considered. All above is collarless blouse’s planning. Base on above result, all objects of clothing life should be teached. For the development of Home Economics Education 1) Understanding and affection of teachers is required. 2) To solve indicated problem, national policy, education plan in school and education finance are fully supported. 3) More studies is required in Home Economics Education.