• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.7
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• pp.53-61
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• 2008

Consider a typical wireless sensor network in which stem nodes form the backbone network of mesh topology while each stem node together with leaf nodes in its vicinity forms a subnetwork of star topology. In such a wireless sensor network, we must heed the following when we design a MAC scheme supporting the packet delivery from a leaf node to a stem node. First, leaf nodes are usually battery-powered and it is difficult to change or recharge their batteries. Secondly, a wireless sensor network is often deployed to collect and update data periodically. Late delivery of a data segment by a sensor node causes the sink node to defer data processing and the data segment itself to be obsolete. Thirdly, extensive signaling is extremely limited and complex computation is hardly supported. Taking account of these facts, a MAC scheme must be able to save energy and support timeliness in packet delivery while being simple and robust as well. In this paper, we propose a version of ALOHA as a MAC scheme for a wireless sensor network. While conserving the simplicity and robustness of the original version of ALOHA, the proposed version of ALOHA possesses a distinctive feature that a sensor node decides between stop and continuation prior to each delivery attempt for a packet. Such a decision needs a stopping rule and we suggest a Bayes stopping rule. Note that a Bayes stopping rule minimizes the Bayes risk which reflects the energy, timeliness and throughput losses. Also, a Bayes stopping rule is practical since a sensor node makes a decision only using its own history of delivery attempt results and the prior information about the failure in delivery attempt. Numerical examples confirm that the proposed version of ALOHA employing a Bayes stopping rule is a useful MAC scheme in the severe environment of wireless sensor network.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.471-476
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• 2020

We propose an practical embodiment-based programming training course for middle school students using Arduino and conduct survey before and after the curriculum. Arduino is an open source physical computing platform that integrates the IDE used in processing language. It is a low-cost, relatively simple I/O interface compared to other platforms, and because of its practical formability, it is educational material suitable for programming. Subsequent surveys will provide feedback on changes in cognition of programming needs and improvement in thinking skills. In this study, the program based on embody-based programming using Arduino was conducted for 8 weeks for each first grade, and 112 middle school students for two years from '16 to '17. Based on the theoretical and practical training, the training was based on the application of the ultrasonic sensor to the RC car and the preparation of the adduction quadrotor drone. The purpose of this study is to prove that the recognition, necessity, and programming education of middle school students are effective for the improvement of thinking ability through the program based on embody-based programming using Arduino.

• Industry Promotion Research
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• v.2 no.2
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• pp.31-44
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• 2017

This study is to investigate the relationship between the communication type recognized by members of organization and the learning transfer climate in the organization, and when it comes to the type of communications within organization set as independent variable, four variables such as communication with supervisor, media quality communication, and organizational outlook communication were proposed and regarding learning transfer climate which is a dependent variable, four sub-parameters such as supervisor support, colleague support, transfer opportunity and organizational compensation recognition were selected. 116 copies of the statistical data excluding statistically insignificant surveys were used for 150 participants who participated in the 2015 core competency curriculum for SMEs and 3 months have passed, in order to achieve this study's objective. Meanwhile, the research hypothesis was verified with the collected data through frequency analysis, factor analysis, reliability verification, technical statistical analysis, and simple and multiple regression analysis by using the statistical package program of SPSS 20.0. Results of this study have shown that firstly, communication with supervisor, media quality communication, and organizational outlook communication all showed a positive (+) significant influence on the superior support in the influence relationship between communication type in organization and supervisor support which is learning transfer climate. Secondly, communication type in organization doesn't appear to affect colleague support of learning transfer climate. Thirdly, communication with supervisor, media quality communication, and organizational outlook except for communication with colleagues have shown a positive (+) influence on transfer opportunity in the influence relationship between communication type in organization and transfer opportunity of learning transfer climate. Lastly, communication with supervisor and communication on organizational outlook showed positive(+) influence in the influence relationship between communication type in organization and organizational compensation recognition of learning transfer climate.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.33-37
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• 2019

In this study, the graded thermal properties of composites are obtained by difference in specific gravity of fillers including Cu, h-BN and GO powders in epoxy. Relatively heavy powders such as Cu and h-BN compared to GO mostly at the bottom layer, while light GO powders were dispersed in the top layer in the composites. The thermal conductivity of composites was gradually increased from 0.55 (0.52) W/mK to 2.82 (1.37) W/mK for GO/h-BN (GO/Cu) epoxy composites from surface to bottom. On the contrary, the coefficient of thermal expansion was decreased from 51 ppm/℃ to 23 ppm/℃ and from 57 ppm/℃ to 32 ppm/℃ for GO/Cu and GO/h-BN, respectively. The variation of thermal properties in composites is attributed due to intrinsic material properties of filler including thermal conductivity, morphology and the distribution by the specific weight of fillers. This simple strategy for realizing graded thermal composites by introducing different filler materials would be effective heat transfer at interface of heterostructure with large thermal properties such as inorganic semiconductor/plastic, metal/plastic, and semiconductor/metal.

• Journal of Agricultural Extension & Community Development
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• v.3 no.2
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• pp.197-209
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• 1996

Bangladesh that is known as the poorest country of the world has the large land of fertile soil and very good environment to live, even though we think she may be very bad to live. People being habituated to that good environment, the population explosion made the people to be starven, but the treatment has been simple support without deep analysis of the root of poverty. As the result it is general that the poverty is severer and severer in spite of continuous support. For the last century Korea changed from the country of poverty and despair to that of development and hope, to be model mid vision of under development countries including Bangladesh. At this point it is necessary to look back the way of development to help them to solve their poverty problem. That is the goal of this project, and this thesis is the result of it. It is evaluated for the 1st 5 years work of the project to apply the result to the next 5 years plan. This project had been proceeded from 1. Jul. 1990 to 30. Jun. 1995 at Chilmari area of Bangladesh, with teaching and training to wake up the mentality of the people, demonstration farming and cooperative association. It was proceeded as the Agriculture project of KDAB(Korean Development Association in Bangladesh, an NGO registered to Bangladesh) supported by Good Neighbors, KOICA and many churches and individuals. Especially the teaching and training work was proceeded as the branch of the Canaan Farmer`s School of Korea with instruction and support. After the basic survey for project, the confirmation of working place and the preparation of training facility, 10 times of long term training(3 months worse, boarding) was completed, with many times of short term training, informal training, demonstration farm, various demonstrating works. The results of the work are understanding of the not of problem by participatory observation, making plan to solve it, getting the trust from the people and beginning the practical work with the trainees for development of economy and living situation. The biggest problem of Bangladesh is being understood losing the desire to solve the poverty problem and the self-confidence to be able to do it. It is the conclusion that after solving the problem of thought and mentality, the education, technology and money can be effective for development. So the 1st 5 year project is evaluated as the basic work to analyse the root of problem, to chance mentality of people and to search income source. The next goal is to promote practical living level of people. For that it is necessary to develope die mentality of people including responsibility and self-confidence by teaching and training, to educate cooperative association and technology for economical development, to proceed integrated rural development work with economical development, educational improvement and reformation of environment. It is very important result that they decided to grow poultry for main economical source of Chilmari area, to do economical development work by joint operation of poultry through cooperative association.

• Journal of architectural history
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• v.3 no.1
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• pp.101-122
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• 1994

This paper is one of the sequels from 'A Survey of Villages and Dwellings of Korean Immigrants in the North-Eastern Part of China'. It is the result of the extensive survey of Ch'ang-ts'ai-tsun village and covers several architectural characteristics of the dwellings. This paper alma to identify the 'double file' dwelling type, which is believed as one of the main stream of Korean folk dwelling. In this type, 'Chung-ju-kan' forms the central open space, where main household functions are carried out. This type originates from climatic reasons and functional reasons as well. This paper also aims to clarify how the dwelling forms are changed according to the life styles of various periods. The Korean immigrants in this village have experienced rapid changes in modern times like other Chinese. Through various political movements, the original dwelling type of this village has changed to adapt various needs and functions, which shows the simple truth : dwelling form changes according to the changes of life style and social structure. In this paper the directions of chimney through various periods are analyzed to verify the differences of the house layout methods and concepts of the time. The village had grown through 3 main periods before liberation period(1946), communization period(1946 - 1966) and contemporary period (1967 - ). It is concluded as follows: 1. The village was originated in late 19th century along the east-west street, which was a major routes of Korean Immigrants to China. In this area there was no regularity in its site plan. The direction of chimney, which was usually westward, was not determined according to the location of gate. This type was kept until liberization of this area, 1946. The plans of dwellings followed Ham-kyong-do 'double file' dwelling type, '6-kan dwelling' or '8-kan dwelling'. 2. The 'New Village' area, which was formed in the communization period, has a strict regularity in its site plan. The direction of chimney was determined as opposite direction of the gate. This method was maintained until 1976, when Mao died and new 'open' policy was held by Chinese government. In this area the 'dwelling house' plan type was not changed, but its layout and size were restricted. The general form of the dwelling in this village was shaped in this period. 3. The contemporary dwellings were built in random site location. The dwelling type was changed because of the reduction of family size and the permissin of private ownership. The number of rooms was reduced but the storage rooms and domestic animal hutches were added. But the 'Chung-ju-kan', the major chacteristics of north-eastern Korea dwelling is still kept. It becomes one large 'Chtin-ju-kan' room like 'open plan' type.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.1
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• pp.123-127
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• 2003

Cornelia de Lange syndrome is a dysmorphogenic disorder characterized by multiple congenital abnormalities, mental retardation, growth retardation and neurodevelopmental abnormalities. Diagnosis for the Cornelia de Lange syndrome is dependent on the clinical observation because neither definite biological marker nor definite chromosomal abnormality have been investigated. Clinical observation is important for the diagnosis, so we report a case of Corenelia de Lange syndrome with mental retardation and autistic disorder. The patient is a 6-year old girl. Her motor development and language development have been delayed. She could say no meaningful word and understood simple command partially. She showed poor eye contact and poor emotional interaction. Social interaction was impaired and she Showed stereotypic behaviors. Thus we diagnosed her as mental retardation with autistic disorder. She had vesicoureteral reflux, frequent upper respiratory infection and pneumonia. She had experienced febrile convulsions 4 times. She had short stature, confluent eyebrows, long eyelashes, and upturned nose with anteverted nostrils. She also showed low hairline and hypertrichosis in body and extremities. Her finger was short. In this case, we diagnosed Cornelia de Lange syndrome by her characteristic face, hypertrichosis and medical and behavioral problems that were frequently showed in this syndrome.

• Korean Journal of Community Nutrition
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• v.15 no.4
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• pp.536-549
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• 2010

The purpose of this study was to investigate food intake, dietary diversity and dietary pattern during the summer in middle aged and older adults living in Gugoksundam (Gurye, Goksung, Sunchang and Damyang counties), Jeonla Province located in southern part of Korea and known as one of the representative Korean longevity areas. Food intake and dietary diversity were assessed by using the data from 2 day-24 hour recall of 1,051 subjects (394 males and 711 females) aged 45 years and older (45-93 years in male, 45-105 years in female). The average ages of males and females were 70.7 years and 71.1 years, respectively. Average total daily food intake was significantly decreased with aging in both genders, and the average animal food intake ratio to total food intake was ranged 10~14% in 3 different age groups, 45~64 years, 65~74 years and 75 years and older. The contribution of each food group, in weight, to total food intake showed the descending order of grains, fruits, vegetables and alcohols in males, and grains, fruits, potatoes and meats in females. On daily intake amount of each food item, rice, watermelon, soju, kimchi, and potato were ranked on top 5 in descending order in males, and rice, watermelon, potato, kimchi and ylmukimchi in females. On intake frequency, rice, kimchi, onion, green pepper and potato were ranked on top 5 in descending order in both genders. Dietary variety score (DVS) and dietary diversity score (DDS) for the assessment of dietary diversity and balance were significantly decreased with aging in both genders. In food group intake pattern (DMGFV), 01101 type without consumption of dairy and fruits was the most prevalent, and only 3.6% of male and 3.9% of female subjects showed 11111 type, consumed all the 5 food groups a day. Dietary pattern of subjects was analyzed by cluster analysis with 18 food groups intake. Overall dietary pattern was classified into two clusters, one was more desirable and the other was less desirable. The percentage of subjects with more desirable dietary pattern was about 15% in male and 32% in female. In conclusion, most of our subjects living in Gugoksundam area were taking very simple diet with low amount of dairy products and fruits. These results indicate that nutrition intervention and education for older people living in rural areas should be focused on various food intake including dairy products and fruits.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.72-78
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• 2020

Demand for cosmetics with functionality and eco-friendliness has increased dramatically due to recent aging, well-being trends, and increased interest in beauty. Cosmetics production in 2014 was 8,970.4 billion won, an increase of about 50% compared to 6,014.6 billion won in 2010. In the midst of this, similar companies in intense competition are pursuing differentiated strategies and innovation activities to solve quality, price and delivery problems. In particular, cosmetics packaging work is getting more difficult due to the increasing bill of materials (BOM) and difficult assembly methods. Therefore, in this study, the following problems were identified and suggestions for the improvement of the packaging Many research laboratories such as biotechnology, chemistry, and pharmaceuticals, which are undergoing various studies, are equipped with ready-made laboratory safety equipments such as bio-safety workbenches, aseptic bases, and exhaust workbenches. However, most researchers are disadvantaged in using existing safety equipment. This is because existing safety equipment can not take into account all of the unique characteristics of the research. For this reason, researchers are demanding the development of customized safety equipment that is well suited to their research needs. process of Company C, which is facing difficult situation to respond to the customer 's delivery due to the 52 - hour work week. First, we used the stopwatch to find the difficulty process in the packaging process and show ways to improve it. Second, to improve the efficiency of line balancing in the packaging process, we integrate processes, improve work methods, and perform simple automation. As a result, the prepare loss for replacement was reduced by 1 minute from 5 minutes, resulting in a 23% increase in productivity from 112 ea./hour to 137ea./ hour per person. At this time, the LOB of the packaging process was improved from 70% to 82% by operating one more production line through one person per line, total 9 people saving.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.3 s.55
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• pp.53-62
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• 2007

This paper presents a new vibration control method for long-span bridges using complex damper system. The new system presents simple mechanical configuration with oil and elasto-plastic dampers which have velocity and displacement dependency in vibration energy absorbing. This system can produce various damping forces according to the applied external forces by the velocity and displacement-dependent characteristics of the dampers. The oil damper dissipates vibration energy for relatively frequent and small amplitude like in the case for small to moderate earthquakes, whereas the elasto-plastic damper system works for rare and large amplitude vibration such as high seismic excitation. Thus, the proposed system exhibits the advantage of low cost with high performance since the roles of the two different dampers are effectively separated. A numerical model is established for the complex damper system, and the response characteristics and effectiveness of the proposed system are presented through numerical simulations. Numerical results show that the proposed complex damper system can significantly improve the seismic performance of long-span bridge structures with much more effective damping mechanism than single conventional passive damper systems.