DTFC에 의한 對稱形 패� 스위칭 컴퓨터망의 POWER特性

박형식,양회국 경북대학교 공과대학 1981 工大硏究誌 Vol.10 No.-

The Performance of DTFC(Drop and Throttle Flow Control), a kind of IBL(Input Buffer Limit) scheme, is observed with respect to several values of threshold L, which controls to accept input packets and transit packets into the input buffer of a node, in the symmetrical packet-switched network. Performance measures are throughput, delay, and power of a tradeoff between throughput and delay. Computer results show that there exist a suboptimal threshold L with respect to throughput, but not with respect to power.

Self-Monitoring Method: Its Utilization in the Field

( Hwoi Sook Choi ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

The relationship between arousal and performance has been one of the most frequently investigated research themes in sports psychology. Particularly, the level of arousal which allows athletes to perform at their optimum is the focus of the interests. However, most literatures simply proposed several theories to account for the relationship between the two. On the other hand, practical sports settings strongly require the following solutions: the identification of optimal arousal levels for individual athletes, the reproduction of such optimal levels, and the development of specific training methods to improve the basic abilities to control those. Therefore, based on the idea of IZOF model (Individual Zones of Optimal Functioning by Hanin, 2000), Choi and Nakagomi have developed psychological training method (named Self-Monitoring Method) to improve athletes` self-control ability, which can lead to their psychological conditioning in practical sports settings (Choi & Nakagomi, 2005, 2006, 2009). In this presentation, focusing on Sports Self-Monitoring Method, the background of our research and the actual state of our training will be described. Then, its utilization in the field will be introduced with case studies.

Effect of Pig Manure Compost or Sucrose Application on Recovering Chinese Cabbage from Ammonium Toxicity

Hyun-Hwoi Ku,Seung-Hwan Kim 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.3

This study was carried out to evaluate the effect of application of urea and combination of urea and pig manure compost (PMC) on the occurrence of and the recovery from ammonium (NH₄<SUP>+</SUP>) toxicity in Chinese cabbage. To identify NH₄<SUP>+</SUP> toxicity of the crop four levels of urea at 0, 160, 320, and 480 kg N ha<SUP>-1</SUP> were applied, in addition, three levels of PMC at 10, 20, and 40 M/T ha<SUP>-1</SUP> was also applied with urea 320 kg ha<SUP>-1</SUP>. For recovery NH₄<SUP>+</SUP> toxicity, six levels of sucrose were treated at the amount of 0, 600, 1,200, 1,800, 2,400, and 3,000 kg Cha<SUP>-1</SUP> at each level of combining treatments of urea and PMC. Our results showed that NH₄<SUP>+</SUP> toxicity was occurred at every urea application of 320 kg N ha<SUP>-1</SUP> regardless of PMC applied to the soils because NH₄<SUP>+</SUP> contents in the soils were more than 155 mg kg<SUP>-1</SUP> which was found to be the critical level to damage crop growth at 2 days after transplanting (DAT) in this experiment, the more sucrose was applied up to 1,800 kg Cha<SUP>-1</SUP> for the plants damaged by ammonium toxicity occurred at 320 kg N ha<SUP>-1</SUP>, the greater extents recover the plants from the toxicity. PMC showed the similar effect with sucrose on recovering Chinese cabbage plants from NH₄<SUP>+</SUP> toxicity at 30 DAT.

Alleviating Effect of the Application of the Easily Decomposable Carbohydrate on Ammonium Toxicity in Chinese Cabbage (Brassica rapa var. chinensis)

Hyun-Hwoi Ku,Sang-Eun Lee 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.5

An excess application of N fertilizer causes physiological and morphological disorder known as ammonium(NH₄<SUP>+</SUP>) toxicity in Chinese cabbage and it has been to be an issue for appropriate N fertilizer management. Hence, the pot experiment was conducted in order to evaluate the alleviating effect of the application of the easily decomposable carbohydrate on NH₄<SUP>+</SUP> toxicity in Chinese cabbage. Four levels of urea at 0, 160, 320, and 640 kg N ha<SUP>-1</SUP>, represented as T1, T2, T3, and T4, respectively, were applied. In order to evaluate the alleviating effect of the application of the easily decomposable carbohydrate (sucrose) at T3 and T4 where NH₄<SUP>+</SUP> toxicity had occurred, five levels of sucrose were applied to meet C/N ratios of 0, 2, 4, 6, and 10, respectively. Our results showed that the NH4+ toxicity was observed at T3 and T4 at 5 days after treatment(DAT). NH4+ toxicity contributed to decrease fresh weight, length of leaves, length of root, and number of leaves significantly (p<0.05). The application of sucrose as a source of mitigating NH₄<SUP>+</SUP> toxicity had a good performance at T3 with the alleviating effect as 73 % and reduced in NH₄<SUP>+</SUP> -N content in soil at 29 DAT. In the maximum N rate of T4, however, sucrose application recovered it as 32 % only compared to T2 even though the same C/N ratio was treated. Consequently, sucrose as the easily decomposable carbohydrate played crucial role to reduce NH₄<SUP>+</SUP> concentration in soil and finally alleviated NH₄<SUP>+</SUP> toxicity in plant.

Measurement of Soil Surface and Plant Canopy Ammonia Fluxes in Red Pepper Field Using Dynamic Chamber Method

Hyun-Hwoi Ku 한국토양비료학회 2020 한국토양비료학회지 Vol.53 No.4

Ammonia (NH₃) gas is the agent of the secondary particulate matter (PM2.5) generated from crop fields amended with organic and inorganic fertilizer application. The purpose of this study is to provide a more reasonable method of calculating NH₃ emissions by comparing amounts of NH₃ gas emitted in the soil surface and plant canopy in red pepper cultivated field. And we used two types of dynamic chamber such as soil surface chamber and plant canopy chamber, for comparing seasonal NH₃ emissions. Ammonia estimated by soil surface and plant canopy chamber methods were 36.4% and 24.1% of total nitrogen applied to field, respectively. The lower NH₃ emission in plant canopy chamber method than that in soil surface chamber method should be attributed to absorption of NH₄⁺ and/or NH₃ by plants. Though soil surface chamber method is widely used, it is necessary to develop method for more accurate estimation of NH₃ emission from crop fields.

Comparison of Different Approaches on Determining Nitrogen Balance in a Lowland Paddy Soil

Hyun-Hwoi Ku 한국토양비료학회 2018 한국토양비료학회지 Vol.51 No.3

Nitrogen (N) balance is a key indicator assessing a degree of soil fertility and N loading by accounting input minus output N in agro-ecosystem. However, a recent approach on determining N balance has been evaluated regarding a change in soil N stock for continuing crop cultivation. To describe an assessment method on N balance, this study was conducted with three different methods, Method A (Input N - Output N (crop N removal+Loss N) = N surplus or deficit), Method B (Input N - Output N (crop N removal+Loss N + Δ soil total N) = N surplus or deficit), and Method C (Input N - Output N (crop N removal+Loss N) + Δ soil total N = N surplus or deficit). Four levels (0, 60, 120, and 180 kg N ha<SUP>-1</SUP>) of N from urea and two levels (120 and 180 kg ha<SUP>-1</SUP>) of N from combination of urea and CM (Urea:Cattle Manure = 60:60 and 60:120) were applied in a lowland paddy soil. Results showed that Method B indicated all negative N values regardless the sources and rates of N application, while Method A and C described different N balance values in the given N applications. Using Method A, a response of N balance to urea applications (0, 60, 120, and 180 kg N ha<SUP>-1</SUP>) was linearly increased. The values of N balance were negative at 0 and 60 kg N ha<SUP>-1</SUP>, while it was close to zero at 120 kg N ha<SUP>-1</SUP> and showed the higher value at 180 kg N ha<SUP>-1</SUP>, respectively. Similarly, the combined N applications at 120 and 180 kg N ha<SUP>-1</SUP> showed similar N balance values. Meanwhile, Method C indicated different N balance values at the combined N applications, showing significantly higher N balance values at 120 kg N ha<SUP>-1</SUP> and the more value at 180 kg N ha<SUP>-1</SUP>, as compared with Method A. The difference was attributed to the soil N stock considering as count factor in determination of N balance. Thus, the study recommended Method C when evaluating both of soil fertility and N loading in crop cultivation field.

Effect of the Application of Sucrose on Rapid Decrease of Soil Inorganic Nitrogen

Hyun-Hwoi Ku(구현회),Woo-Jin Lim(임우진),Sang-Eun Lee(이상은) 한국토양비료학회 2010 한국토양비료학회지 Vol.43 No.4

질소 비료 과용에 의한 토양 무기태 질소의 과다 축적과 그에 따른 염류 집적이 심각한 시설원예 토양의 문제점을 해결하기 위하여, C/N율이 높은 이분해성 탄수화물의 시용이 토양 무기태 질소 함량과 전기전도도 감소에 미치는 영향을 실내 실험을 통하여 검토하였다. sucrose의 처리는 토양 NH₄<SUP>+</SUP>-N 함량을 크게 감소시켰는데, 감소량은 sucrose 처리량이 많을수록 컸으며, NH₄<SUP>+</SUP>-N 함량을 최저점 (약 10 mg kg<SUP>-1</SUP> 이하)에 도달하게 할 수 있는 sucrose 처리량은 최초의 NH₄<SUP>+</SUP>-N 함량에 관계없이 C/N율로 약 10부근이었다. sucrose 처리는 토양 NH₄<SUP>+</SUP>-N 함량을 매우 빠르게 감소시켰는데, 최초 NH₄<SUP>+</SUP>-N 함량 50~250mg kg<SUP>-1</SUP>을 1/2로 감소시키는데 15~36시간이 걸렸으며, 최저점 (약 10 mg kg<SUP>-1</SUP> 이하)으로 감소시키는 데에는 36~69시간이 걸렸다. sucrose 처리는 토양 NO₃<SUP>-</SUP>-N 함량을 큰 폭으로 감소시켰는데, 감소량은 처리량이 많을수록 컸으며, sucrose 처리량이 C/N율로 10 이상인 경우에는 최초 348 mg kg<SUP>-1</SUP> 이었던 NO₃<SUP>-</SUP>-N 함량이 최저 14~21 mg kg<SUP>-1</SUP>으로 감소하였다. sucrose 처리는 토양 NO₃<SUP>-</SUP>-N 함량을 매우 빠르게 감소시켰는데, 토양 NO₃<SUP>-</SUP>-N 함량을 최저점으로 감소시키는데 걸리는 시간은 sucrose 처리량이 C/N율로 10이상인 경우에는 36~60시간이 걸렸으며, 처리량이 C/N율 5로 적었던 경우에는 3주로서 상대적으로 긴 시간이 걸렸다. sucrose 처리에 의한 토양 EC의 감소는 NO₃<SUP>-</SUP>-N 함량의 감소와 같은 양상을 보였다. 논문의 결과를 응용함에 있어서 명심해야될 사항이 있다. 설탕은 인류에게 에너지와 탄소 원 (原)을 공급하는 매우 중요한 자원이므로 특별한 경우가 아니면 토양에 시용하는 것을 피해야 한다. 토양의 염류집적을 막는 최선의 방법은 시비량을 줄이는 일이며, 염류가 집적된 후에 여러 대응방안을 강구하는 것은 사후약방문 (死後藥方文)에 불과하다. To solve the problems with excessive accumulation of soil inorganic N and resulting saline soils from overuse of nitrogen fertilizer, the effect of sucrose application on decrease of soil inorganic N content and electrical conductivity (EC) was studied. Sucrose treatment greatly reduced NH₄<SUP>+</SUP>-N content in soil. The amount of reduction was greater as the amount of sucrose treatment was increased. When NH₄<SUP>+</SUP>-N content was reached the lowest point (about 10 mg kg<SUP>-1</SUP>or lower), the C/N ratio, which determines the amount of sucrose treatment, was around 10 regardless of initial NH₄<SUP>+</SUP>-N content. For the rate of NH₄<SUP>+</SUP>-N reduction 15~36 hours was required to reduce the initial NH₄<SUP>+</SUP>-N content to half, and 36~69 hours to lower NH₄<SUP>+</SUP>-N content to the lowest point (about 10 mg kg-1or lower). In addition, sucrose treatment greatly lowered NO₃<SUP>-</SUP>-N content. In case of C/N ratio above 10, initial NO₃<SUP>-</SUP>-N content of 348 mg kg<SUP>-1</SUP> was reduced to the lowest of 14~21 mg kg<SUP>-1</SUP>. As for the rate of NO₃<SUP>-</SUP>-N reduction by sucrose treatment, it took 36~60 hours for NO₃<SUP>-</SUP>-N content to reach the lowest point for C/N ratio of 10 or higher, and it took 3 weeks, comparably longer time, for C/N ratio of 5. Lowering soil EC from sucrose treatment showed the same trend as NO₃<SUP>-</SUP>-N content. As an important energy and carbon source for humankind, sugar should not be wasted and must be carefully applied to soil. In principle, the best way of preventing salt accumulation in soil is to optimize the fertilizer input. However, when over-fertilization should be dealt with, the sucrose treatment would be a possible and effective counter-measure to reduce overdosed nitrogen sources in soil.

A Case Study of School Safety Practices in France and Japan

Kyung Hwoi Kim,Hyun Joo Lee,Day Young Oh,Josh Sung Chang Ryoo 위기관리 이론과 실천 2018 Crisisonomy Vol.14 No.8

The article examines school safety practices in France and Japan in order to seek insightful information for school safety policy in Korea. School safety training in France characterizes: 1) participation in professional development of school safety program is open to teachers, and 2) community safety agencies such as fire stations help school to operate the program. School safety education for students in Japan is featured as follows: 1) schools train students to prepare natural disasters regularly and tightly, 2) school safety manuals are well prepared and tailored to unique risks in each school. The controversial issues around the adoption of the practices in France and Japan to the Korean educational context include the scope of professional development programs about school safety and the revision of safety manuals according to disaster characteristics. 본 연구는 프랑스의 안전교육 전문교사 연수과정과 일본의 재난대응 학생 훈련과정을 심층 분석하여 우리에게 주는 시사점을 논구하고 있다. 프랑스는 학교에서 안전교육 담당자를 교사의 자발적 참여와 학교 외 유관기관의 협력을 얻어 양성하고 있다. 모든 교사를 안전교육 전문가로 연수하기보다는 희망자를 대상으로 심층 연수하여 안전교육 담당자로 배치하고 있다. 연수프로그램은 이론과 경험, 일반론과 특수론의 균형을 중요시한다. 한국의 ‘학교안전관리사’ 국가자격증 도입에 앞서 프랑스처럼 희망교사를 대상으로 연수를 통한 안전교육 전문교사를 양성하는 것을 검토할 필요가 있다. 일본의 학생대상 재난대응 훈련은 조직적이고 체계적이며, 재난유형별 교육훈련 매뉴얼은 완성도가 높으면서 학교별 위험 특성을 반영하여 작성된다. 우리도 지역과 학교의 재난특성에 맞춰 재난 메뉴얼을 작성하고 이에 따라 재난대응훈련이 필요하다. 또한, 일본처럼 학교에서 재난대응 계획수립과 훈련에서 지역사회 및 가정과의 연계를 강화해야할 것이다.

시호의 형태 감별에 관한 연구

양회정 ( Hwoi Jeong Yang ),길기정 ( Ki Jung Kil ),이영종 ( Young Jong Lee ) 대한본초학회 2004 大韓本草學會誌 Vol.19 No.2

N/A Objective : In order to reveal the morphological characteristics of Bupleuri Radix prevailed in Korea, the raw and artificial Bupleurum falcatum L. and the raw B. longiradiatum Turcz. were collected., and their external, internal, and flour states were observed via microscopic examination. Method : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and the flour of it was mounted by the liquid made by the same ratio of each of glycerin, acetic acid, and water, and then observed and photographed by olymphus -BHT. Result 1. The external form of B. falaztum L., plant root, looked like a circular cone and had no room between the joints. However, B. longiradiatum Turcz., plant rhizome, had well-articulated joints where many small roots were attached with a cavity in the middle of pith of its slice. 2. The internal form of B. falcatum L. has cork layers composed of 7~8 lines of cells, and 6~8 secretory cells were found around vitta. The cork layers of B. longiradiatum Turcz. was composed of over 10 lines of cells, and 10~20 secretory cells were distributed around vitta. 3. In the flour form, B. longiradiatum Turcz. contains rhizome epidermal cell, which was not observed in B. falcatum L.. Moreover, stoma was not consistently arranged. Conclusion There were differences in external, internal, and flour states between B. falcatum L. and B. longiradiatum Turcz., so that microscope can be used to distinguish between these two.

Nondestructive and Rapid Estimation of Chlorophyll Content in Rye Leaf Using Digital Camera

Hyun Hwoi Ku,Seung Hwan Kim,Kwan Soo Choi,Ho-Yong Eom,Sang-Eun Lee,Seung-Gil Yun,Tae Wan Kim 韓國作物學會 2004 Korean journal of crop science Vol.49 No.1

We have developed and tested a new method for nondestructive estimation of chlorophyll- and nitrogen-contents in rye leaf. It was found that the relation-ships among nitrogen, chlorophyll content and fresh weight were significantly positive correlated. Nitrogen and chlorophyll content were positively correlated whereas correlation coefficients among R, G, R-B and G-B on the basis of photo-numerical values were negative. We have found that R/(R-B) obtained from data of digital camera is the best criterion to estimate the chlorophyll content of leaves. The regression curves of the relation between R/(R-B) and chlorophyll content were also calculated from the data collected on cloudy days. The coefficients of determination (~textrmr2 ) were ranged from 0.33 to 0.99. In this study, the accuracy in estimating chlorophyll content from the color data of digital camera image could be improved by correcting with R, G, and B values. It is suggested that, for practical purposes, the image values estimated with sufficient accuracy using a portable digital camera can be applied for determining chlorophyll content and nitrogen status in plant leaves.