• Journal of Korean Society for Atmospheric Environment
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• v.21 no.4
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• pp.459-469
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• 2005

In recent years, concerns have been growing globally regarding greenhouse gases. Open burning of biomass causes emission of a number of greenhouse and other gases and substances. This paper studied an analysis on the characteristics of four types of biomass using duel type cone calorimeter. Cone calorimeter is widely used for assessing combustibility of materials in Europe. As a result, we evaluated several characteristics of biomass, such as heat released rate, smoke production rate, CO, $CO_2$ production and mass loss rate, and so on. $CO_2$ is currently responsible for over $60\%$ of the enhanced greenhouse effect, and may be the most important contributor to future. $CO_2$ production for biomass in the range of $1.74\~1.99kg/kg$ is similar to previous research conducted by Bhattacharya et al. (2002a).

• The Korean Journal of Ecology
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• v.18 no.1
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• pp.137-146
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• 1995

Acer pseudo-sieboldianum, A. ginnala, A. negundo and A. saccharinum were selected as materials for the studies on the seasonal fluctuation of chlorophyll content and photosynthetic rates. In all the four species during the growing season except in October, the principal component that determined the total chlorophyll content was chlorophyll a. Content of chlorophyll b increased with leaf age, but that of chlorophyll a decreased. In contrast to A. saccharinum and A. pseudo-sieboldianum which showed their maximum chlorophyll content in June, A. negundo, which showed the highest chlorophyll content of the four species, exhibited its maximum chlorophyll content in July, whereas September in the case of A. ginnala. The fluctuation of chlorophyll content was similar to that of air temperature, and it increased till July. But chloprophyll content showed a significant relationship in early stage of leaf development, and there could be any interdependence between them in accordance with the seasonal change, no longer. In all four species light compensation points decreased in accordance with the seasonal change, and the maximum photosynthetic rates were obtained in August. Respiratory rates were shown no significant difference among species, and they decreased according to the adbance of season.

• The Journal of Korean Medical History
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• v.29 no.1
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• pp.11-31
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• 2016

Objectives : The goal of this paper is to research what affected diagrams of lung originated from Ming Tang Zang Fu Tu during the time they were changed in. Methods : Diagrams of lung in Traditional Chinese and Japanese medical books had been collected as many as possible. Besides being grouped by Huang Longxiang (黃龍祥)'s classification, they were analysed by 4 form factors, e.g. shape, number, veins and petiole of leafs. Results : Reliability of this methods had been checked on by the correspondence with Huang's 14 standard books, before 29 diagrams of lung were selected from 33 books including 13 books that Huang had already made his proposal. The lobes in most of diagrams resembled 6 lanceolate or long oval leafs, or a maple leaf with 5 indentations. In most of diagrams, veins of leafs were described variously, more or less than 9 nodes often drew in petioles. Conclusions : Suwen (素問), Nan Jing (難經) and Wang Bing would had steadily worked on 29 diagrams of lung, since diagram of lung stemmed from Ming Tang Zang Fu Tu, went out into the world in Zhen Jiu Ju Ying (鍼灸聚英). But they were not drawn through dissection during same periods.

• Journal of the Korea Furniture Society
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• v.28 no.3
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• pp.233-247
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• 2017

Woodcraft activities have an inseparable relationship with our daily life, and it is a field that needs to be continued because of the value of education for the growing students. The interest in woodworking from childhood to old age is rapidly expanding nowadays, therefore this study has been done to provide images to those who are engaged in woodcraft business and also those who are interested in this field. If we look at the use of wood in our daily life, We can classify it into Architecture, Civil engineering, Furniture, Musical Instrument, Packaging, Recreational instrument, Exercise instrument, Stationery, Daily commodity, and Industrial use. Among them, We examined kinds of stationery and which type of woods were used. As a result of classifying 101 stationery products in 22 countries, stationery materials using wood can be used for Business cards, Envelope houses, Box houses, Pen holders, Locker plates, Stationery baskets, Book holders, Stamps, Paper knives, Bookmarks, and Photo frames. It was found various wooden stationery are made in USA, Japan, UK, Canada etc. And the most frequently used species are hardwoods such as Walnut (Juglans regia), Maple (Acer spp.), Cherry (Prunus serotina), Birch (Betula spp.), Mahogany (Swietenia macrophylla), Tulip (Liriodendron tulipifera Linnaeus), Bubinga (Guibourtia tessmannii J. Leonard), Wenge (Milletia laurentii De. wild), Cocobolo (Dallbergia cultrata Grah), Zebrawood (Microberlinia brazzavillensis A. Chev.) and Ebony (Diospyros spp.).

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.103-108
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• 2012

Radiofrequency(RF) signal is a key medium to the most of the present wireless communication devices including RF identification devices(RFID) and smart sensors. However, the most critical barrier to overcome in RFID application is in the failure rate in detection. The most notable improvement in the detection was from the introduction of EPC Class1 Gen2 protocol, but the fundamental problems in the physical properties of the RF signal drew less attention. In this work, we focused on the physical properties of the RF signal in order to understand the failure rate by noting the existence of the ground planes and noise sources in the real environment. By using the mathematical computation software, Maple, we simulated the distribution of the electromagnetic field from a dipole antenna when ground planes exist. Calculations showed that the dark area can be formed by interference. We also constructed a test system to measure the failure rate in the detection of a RFID transponder. The test system was composed of a fixed RFID reader and an EPC Class1 Gen2 transponder which was attached to a scanner to sweep in the x-y plane. Labview software was used to control the x-y scanner and to acquire data. Tests in the laboratory environment showed that the dark area can be as much as 43 %. One who wants to use RFID and smart sensors should carefully consider the extent of the dark area.

• Korean Institute of Interior Design Journal
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• no.37
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• pp.95-102
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• 2003

It has been true that major investment among local business hotels were placed in furniture design character as there are increasing number of international events hosted by Korea. The study, under these circumstances, as a study In advance to see the design feature and trend of local business hotel's guest room furniture, has done interview with guest room manager, photographing of rooms, actual survey for analysing guest room plane surface, etc., researcher directly visiting 15 hotels that have special first grade businessmen only floor in Seoul. In addition, a survey has been done to know if each hotel room and furniture has particular image, from this survey the design feature of local business hotel's guest room has been analysed, and the result is as following. The result shows that similar pattern is applied in furniture placement of each guest room but for the furniture type and design concept, some try to re-design of wooden furniture available in Lee dynasty and others adopt European style like France and United Kingdom for the realization of semi-classic image. Typical material and color is red oak and maple.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.843-847
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• 2014

In Super Junction (SJ) MOSFETs, charge balance is the most important issue of the SJ fabrication process. In order to achieve the best electrical characteristics, such as breakdown voltage and on-resistance, the N-type and P-type drift regions must be fully depleted when the drain bias approaches the breakdown voltage, which is known as the charge balance condition. In conventional charge balance analysis, based on multi-epi process SJ MOSFETs, analytical model has only N, P pillar width and doping concentration parameter. But applying a conventional charge balance principle to trench filling process, easier than Multi-epi process, is impossible due to the missing of the trench angle parameter. To achieve much more superior characteristics of on-resistance in trench filling SJ MOFET, the appropriate trench angle is necessary. So in this paper, modulated charge balance analysis is proposed, in which a trench angle parameter is added. The proposed method is validated using the TCAD simulation tool.

• Communications of Mathematical Education
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• v.24 no.1
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• pp.29-48
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• 2010

The purpose of this paper is to discuss about the use of technology in teaching-learning school mathematics. In this paper, we study the theoretical background of teaching-learning school mathematics by the use of technology. For the purpose of successful use of technology in teaching-learning school mathematics, we research the present states of it appeared in textbooks of high school mathematics And we give suggestions for the effective use of technology in teaching-learning school mathematics. Furthermore, we introduce models for teaching-learning school mathematics in areas of mathematics by the use of computer programs such as GSP, Maple, and GrafEq.

• Structural Engineering and Mechanics
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• v.70 no.5
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• pp.601-621
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• 2019

This study presents a comprehensive nonlinear dynamic approach to investigate the linear and nonlinear vibration of sandwich plates fabricated from functionally graded materials (FGMs) resting on an elastic foundation. Higher-order shear deformation theory and Hamilton's principle are employed to obtain governing equations. The Runge-Kutta method is employed together with the commercially available mathematical software MAPLE 14 to solve the set of nonlinear dynamic governing equations. Method validity is evaluated by comparing the results of this study and those of previous research. Good agreement is achieved. The effects of temperature change on frequencies are investigated considering various temperatures and various volume fraction index values, N. As the temperature increased, the plate frequency decreased, whereas with increasing N, the plate frequency increased. The effects of the side-to-thickness ratio, c/h, on natural frequencies were investigated. With increasing c/h, the frequencies increased nonlinearly. The effects of foundation stiffness on nonlinear vibration of the sandwich plate were also studied. Backbone curves presenting the variation of maximum displacement with respect to plate frequency are presented to provide insight into the nonlinear vibration and dynamic behavior of FGM sandwich plates.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.324-324
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• 2021

2020년 우리나라 중부지역의 장마철('20.6.10.~8.16.) 기간이 54일로 1973년 전국적인 기상관측을 시작한 이래 가장 길었고, 장마철 전국강수량(686.9mm)은 역대 2위로(1위 '06년 699.1mm) 약 8,000여명의 수재민과 42명의 인명피해가 발생하였다. 이처럼 '이상기후'라 부르는 극한 기상 사건들인 홍수, 폭우, 폭염, 가뭄 등의 자연재해가 해마다 우리나라 포함 전 세계적으로 자주 발생하면서 수문기상 정보 관리 및 활용의 중요성 또한 점차 커지고 있다. 이를 위해 기상청에서는 일반국민과 물관리 관계기관(회원)의 편의와 자료의 활용 증진을 위해 유역별 수문기상 관측·예측 정보를 생산하여 서비스를 제공하고 있다(https://hydro.kma.go.kr). 수문기상 관측 정보는 유역별 면적강수량, 증발산량 등을 산출하여 GIS기반으로 실시간 자료와 2000년 이후 과거 관측강수량의 기간(월, 계절, 연)자료를 제공하며, 예측 자료는 초단기 수치 모델(KLAPS), 레이더(MAPLE), 수문기상 예측모델(UM3km), 한국형 수치 예보 모델(KIM)을 활용하고 있다.