신뢰모델기반의 ZigBee 네트워크 구성 및 신뢰성 측정

황재우,박호현,Hwang, Jae-Woo,Park, Ho-Hyun 한국정보통신학회 2010 한국정보통신학회논문지 Vol.14 No.5

USN을 구성 하는 중요 기술로 평가 받고 있는 ZigBee는 근거리 통신을 지원하는 IEEE 802.15.4 표준 가운데 하나로, 라우팅 방식으로 주소 할당 방식을 바탕으로 한 계층적 라우팅과 라우팅 테이블에 기반을 둔 요구형 경로 탐색 방식을 지원한다. 계층적 라우팅은 라우팅 테이블을 사용하지 않고, 자식 노드 또는 부모 노드를 중간 노드로 선택 하여 데이터를 전달하기 때문에 네트워크 토폴로지가 전체적인 네트워크 성능을 좌우하게 된다. 본 논문에서는 ZigBee 네트워크 구성 시 깊이와 편차가 큰 LQI 값만을 이용하여 부모 노드를 선택하는 방식에서 신뢰 모델을 추가 하여 좀 더 신뢰성 있는 네트워크 토폴로지를 구성하는 알고리즘과 신뢰 모델을 활용하여 전체적인 네트워크의 신뢰도를 측정하는 방법을 제안하였고 NS-2를 이용한 네트워크 시뮬레이션과 MG2400 ZigBee 보드로 구현하여 성능을 검증하였다. The ZigBee is one of the most important technologies for composing USN. It is one of the IEEE 802.15.4 standards to support personal area networks. It uses a hierarchical routing or an on-demand route discovery strategy as an address allocation method. A hierarchical routing doesn't use a routing table but only uses a child node or a parent node as an intermediate node for data delivery. Therefore, the ZigBee network's topology greatly affects the overall network performance. In this paper, we propose a more trustworthy algorithm than only using the depth and widely variable LQI during network formation, and moreover we propose an algorithm to measure network's trustworthiness. We simulate our algorithm using the NS-2 and implement our network using the MG2400 ZigBee module for verifying performance.

반송 ( Pinus densiflora for . multicaulis ) 의 몇 가지 동위효소의 유전변이

황재우(Jae Woo Hwang),이석우(Seok Woo Lee) 한국산림과학회 1996 한국산림과학회지 Vol.85 No.3

Isozyme variations in 4 enzyme systems in Pinus densiflora for. multicaulis in 31 individual trees collected throughout the country were studied by starch gel electrophoresis using haploid megagametophyte tissue to compare with those of Prinus densiflora. A minimum of 7 loci were found to code for isozymes of the enzyme systems. No variation was found at locus GOT-A; at the remaining 6 variable loci (GDH-A, GOT-B, GOT-C, IDH-A, LAP-,A, LAP-B) and 2 to 4 alleles were identified. We could not find azy marker alleles to distinguish Pinus densiflora for. multicaulis from Pinus densiflora at the isozymes studied here. Allele frequency distributions at each loci were almost all the same as those of P. densiflora. The percentage of polymorphic loci(99% level), the number of alleles per locus, the observed and expected heterozygosities were 85.7, 2.3, 0.165 and 0.186%, respectively. The level of genetic diversity in Pinus densiflora for. multicaulis seemed to be less than that of P. densiflora.

고등학교 기하와 벡터 과목에서 풀이과정 서술의 오류 분석

황재우 ( Hwang Jae-woo ),부덕훈 ( Boo Deok Hoon ) 한국수학교육학회 2017 수학교육 Vol.56 No.1

By analysing the examination papers from third grade high school students, we classified the errors occurred in the problem solving process of high school `Geometry and Vectors` into several types. There are five main types ― (A)Insufficient Content Knowledge, (B)Wrong Method, (C)Logical Invalidity, (D)Unskilled Expression and (E)Interference.. Type A and B lead to an incorrect answer, and type C and D cannot be distinguished by multiple-choice or closed answer questions. Some of these types are classified into subtypes ― (B1)Incompletion, (B2)Omitted Condition, (B3)Incorrect Calculation, (C1)Non-reasoning, (C2)Insufficient Reasoning, (C3)Illogical Process, (D1)Arbitrary Symbol, (D2)Using a Character Without Explanation, (D3) Visual Dependence, (D4)Symbol Incorrectly Used, (D5)Ambiguous Expression. Based on the these types of errors, answers of each problem was analysed in detail, and proper ways to correct or prevent these errors were suggested case by case. When problems that were used in the periodical test were given again in descriptive forms, 67% of the students tried to answer, and 14% described flawlessly, despite that the percentage of correct answers were higher than 40% when given in multiple-choice form. 34% of the students who tried to answer have failed to have logical validity. 37% of the students who tried to answer didn`t have enough skill to express. In lessons on curves of secondary degree, teachers should be aware of several issues. Students are easily confused between `focus` and `vertex`, and between `components of a vector` and `coordinates of a point`. Students often use an undefined expression when mentioning a parallel translation. When using a character, students have to make sure to define it precisely, to prevent the students from making errors and to make them express in correct ways.

Genetic relationship among acer species revealed by RAPD and PCR-RFLP

Jae Woo Hwang(黃在禹),Eun Woon Noh(盧銀雲),Jae Soon Lee(李載順),Sook Kyung Park(朴淑京) 한국육종학회 1996 한국육종학회지 Vol.28 No.4

Ten different species of Acer including A. triflorum, A. saccharinum, A. pseudo-sieboldianum, A paimatum var. sanguineum, A. mono, A. ruburm, A. negundo, A. palmatum, A ginnala, and A. tegmentosum were compared with regard to their DNA variation based on RAPD profiles and PCR-RFLP. For RAPD study, only five species(A. triflorum, A. saccharinum, A pseudo-sieboldianum, A. palmatum var. sanguineum, and A. mono) consisting of more than 5 individuals were compared. For PCR-RFLP, 6 species that produced the target bands with the sequence specific primers were considered. Forty four loci were generated by RAPD with 4 arbitrary primers. Similarity between individuals was estimated by calculating the frequency of shared bands out of total bands. Cluster analysis based on the similarity produced two groups. While the first group was exclusively composed of A. pseudo-sieboldianum, the second comprised the remaining 4 species. When the primers specific to the gene sequences rpl2 and psbA in chloroplast DNA were used, A pseudo-sieboldianum again appeared to have different amplification pattern from the rest of Acerspecies examined. Analysis of the amplified psbA-rpl2 region(1.7 kb) by PCR-RFLP revealed that the species in the genus could be readily differentiated from each other by the fragmentation profile. We found that although RAPD worked on Acer species, it costed too much time and labor for the optimization of PCR conditions. On the other hand, the PCR-RFLP technique is very simple and straight forwarded to get reproducible results since it uses very stringent reaction conditions.

선다형 문제와 서술형 문제의 점수 차이와 이에 대한 학생들의 인식-고등학교 기하 교과를 중심으로-

황재우 ( Hwang Jae-woo ),부덕훈 ( Boo Deok Hoon ) 한국수학교육학회 2018 수학교육 Vol.57 No.3

Descriptive problems can be used to grow student’s ability of thinking logically and creatively, because it shows if the students had a reasonable way of thinking. Rate of descriptive problems is increasing in middle and high school exams. However, students in middle and high schools are generally used to answering multiple-choice or short-answer questions rather than describing the solving process. The purpose of this paper is to gain a theoretic ground to increase the rate of descriptive problems. In this study, students were to solve some multiple-choice problems, and after a few weeks, to solve the problems of same contents in the form of descriptive problems which requires the students to write the solving process. The difference of the scores were measured for each problems to each students, and students were asked what they think the reason for rise or fall of the score is. The result is as follows: First, average scores of 7 of 8 problems used in this study had fallen when it was in descriptive form, and for 5 of them in the rate of 11.2%~16.8%. Second, the main reason of falling is that the students have actual troubles of describing the solving process. Third, in the case of rising, the main reason was that partial scores were given in the descriptive problems. Last, there seems a possibility gender difference in the reason of falling. From these results, followings are suggested to advance the learning, teaching and evaluation in mathematics education: First, it has to be emphasized enough to describe the solving process when solving a problem. Second, increasing the rate of descriptive problems can be supported as a way to advance the evaluation. Third, descriptive problems have to be easier to solve than multiple-choice ones and it is convenient for the students to describe the solving process. Last, multiple-choice problems have to be carefully reviewed that the possibility of students’ choosing incorrect answer with a small mistake is minimal.

중학교 기하 증명의 서술에서 나타나는 오류의 유형 분석

황재우 ( Jae Woo Hwang ),부덕훈 ( Deok Hoon Boo ) 한국수학교육학회 2015 수학교육 Vol.54 No.1

By analysing the examination papers for geometry, we classified the errors occured in the proofs for geometric problems into 5 main types - logical invalidity, lack of inferential ability or knowledge, ambiguity on communication, incorrect description, and misunderstanding the question - and each types were classified into 2 or 5 subtypes. Based on the types of errors, answers of each problem was analysed in detail. The errors were classified, causes were described, and teaching plans to prevent the error were suggested case by case. To improve the students`` ability to express the proof of geometric problems, followings are needed on school education. First, proof learning should be customized for each types of errors in school mathematics. Second, logical thinking process must be emphasized in the class of mathematics. Third, to prevent and correct the errors found in the proofs for geometric problems, further research on the types of such errors are needed.

공동주택 친환경건축물인증 사례를 통한 평가항목 개선안 연구

김명신(Myoung-Shin Kim),황재우(Jae-Woo Hwang),박경순(Kyung-Soon Park),손원득(Won-Tug Son) 한국산업융합학회 2008 한국산업응용학회 학술대회 논문집 Vol.- No.-

The Green Building Certification is issued through self-assessment of applicant, assessment of assessment members and deliberation committee members. These assessments are carried out based on a standard provided Ministry of land transport and maritime affairs and environment. However, opinion difference of assessment standards could be occurred due to diversity of understanding for a standard or subjectivity of committee member. In this paper, We discussed the primary cause of score difference after analyzed assessment standard for the site, transportation, energy and resources, ecological environment, indoor environment in five different Apartment Houses located in Seoul. At a result, score difference was at least 3 points in each section except indoor environment and total score difference of housing complex is by 10 points. To improve these problems, educational program should be activated and guide for assessment standard should be published.

질소 (窒素) 시비 (施肥)와 간벌 (間伐)이 잣나무 당년생 침엽과 소지의 생장 및 양분에 미치는 영향

손요환(Yo Whan Son),황재우(Jae Woo Hwang),이도형(Do Hyeung Lee),김종성(Jong Sung Kim),양수영(Soo Young Yang) 한국산림과학회 2001 한국산림과학회지 Vol.90 No.1

To investigate the effects of nitrogen fertilization and thinning on growth and nutrition of current-year needle and twigs in Pinus koraiensis we treated two clone banks with three levels of nitrogen fertilizer in Yongin and Chuncheon, and also thinned two plantations with three intensities in Yangpyeong. The fertilization and thinning effects greatly varied depending on study sites and stand ages. However, dry weights of needle and twig increased following low nitrogen fertilization in older stands. Moderate thinning increased dry weight and nitrogen concentration of twigs in the 12-year-old stand.

주택성능등급과 친환경건축물인증의 평가방법 비교를 통한 개선안 연구 : 환경관련등급을 중심으로

김명신(Myoung-Shin Kim),황재우(Jae-Woo Hwang),천정길(Jung-Gil Chun),하대웅(Dae-Woong Ha),박경순(Kyung-Soon Park),손원득(Won-Tug Son) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

A variety of Certification systems are initiated, as increased demands for housing quality of building & house owner. New building and apartment built in Seoul metropolitan should acquire Building Energy Rating System and Housing Performance Grade indication System, Green Building Certification System. Building Energy Rating System could be acquired through the certification from energy performance index of environment grade in Housing Performance Grade Indication. Between Housing Performance Grade Indication and Green Building Certification System, There are troublesome to acquire certification because a lot of assessment items are overlapped. At a result, the rational and efficient certification system should be initiated not only to avoid overlap among those certification systems and promote Green Building market share but also efficient certification system operation. We will discuss on assessment items between Housing Performance Grade Indication System and Green Building Certification System and release the improvement method those Certification Systems to avoid overlapping to assessment items.

몬티콜라잣나무 ( Pinus monticola ) 묘목의 생리적 차이와 잣나무털녹병 감염률과의 관계

우관수(Kwan Soo Woo),황재우(Jae Woo Hwang),강건우(Gun Uh Kang),이헌호(Heon Ho Lee),이인중(In Jung Lee) 한국산림과학회 2002 한국산림과학회지 Vol.91 No.4

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