• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.3
• /
• pp.1-7
• /
• 2012

In this paper, we consider a channel selection method for the coexistence of heterogeneous systems in the TV white space (TVWS). First, we define the target heterogeneous system structure. Then, under the defined system structure, we discuss how the heterogeneous systems share the TVWS channels. Specifically, the heterogeneous systems having different bandwidths cannot use the TVWS channels due to the lack of wideband channels when only narrowband channels are remained. Hence, in order to minimize the blocking from the different bandwidth problem, we propose a channel selection method for the narrowband systems to firstly occupy the narrowband channels rather than the wideband channels. The proposed narrowband-first channel selection is shown to enhance the spectral efficiency of the TVWS, especially in the IEEE 802.19.1 wireless coexistence system.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06d
• /
• pp.261-266
• /
• 2007

그리드 컴퓨팅은 이질적인 환경에서 자원 공유를 가능하게 함으로써 작업을 효율적으로 수행할 수 있는 환경을 제공한다. 현재 그리드 컴퓨팅의 환경은 유선 그리드 환경에 모바일 장치들을 통합하는 무선 그리드와, 사용자의 이동성을 고려한 모바일 그리드 환경으로 진화하고 있다. 모바일 장치는 성능 면에서 비약적으로 증가하고 있고, 최근 몇 년 사이에 사용자도 많이 늘어났다. 따라서 본 논문에서는 모바일 그리드 환경에서 모바일 장치를 자원으로 이용하기 위하여 모바일 장치의 특성을 고려한 결함 포용적 자원 선택 알고리즘을 제안한다. 이 알고리즘은 1) 모바일 장치의 배터리 잔류량 정보, 이동성 정보, 장치의 성능 정보를 고려하여, 2) 모바일 장치들의 순위를 계산하고 k개의 그룹으로 분류한 뒤, 3) 작업을 할당할 때 결함 포용을 고려하여 최상위 그룹과 차상위 그룹에 동시에 작업을 분배한다. 모바일 장치의 순위를 매기고 그룹화하는 과정은 모바일 장치의 동적인 특성을 고려하여 작업이 요청될 때마다 수행하도록 한다.

• The Journal of Korean Association of Computer Education
• /
• v.7 no.5
• /
• pp.71-82
• /
• 2004

The purpose of the study was to suggest policy implications to support K-12 education, especially weak areas, through e-Learning, With the literature review and discussions among experts in the field of K-12 education, we identified three areas - support for neglected students, preference-based curriculum, and gifted education - as the ones e-Learning may contribute much, and discussed current situations and problems for the each area followed by policy implications accordingly. In addition, we suggest strategic bases for the policy implications, which were reform of the law and polices, contents sharing, and quality control of e-Learning.

• Korean Journal of Cognitive Science
• /
• v.12 no.4
• /
• pp.29-39
• /
• 2001

Kaplan(2000) reported that instances were categorized more accurate in the aligned condition than in the non-aligned condition irrespective of similarity between instances[16]. This study investigated wether Kaplan(2000)\\`s results could be explained by stimulus types she used and alignment effects in categorization were due to selective attention to aligned attributes. In Experiment 1. I examined whether attribute alignment produced significant effects on similarity and categorization and aligned attributes were recalled more than non-aligned ones. Results showed that instances were rated more similar and categories were learned more rapidly in the aligned condition than in the non-aligned condition. It can be explained that categories are learned rapidly in the aligned condition because attribute alignment increases within-category similarity. But. the result that aligned attributes were recalled more than non-aliened ones in the attribute recall test implies that alignment effects in categorization can be independent of similarity between instances partially. In Experiment 2. I used equal numbed of attributes defining two categories and instructed subjects to pay their attention to categorization-relevant dimensions only. Results showed that dimension instruction facilitated category learning in the non-aligned condition only but categories were learned more rapidly in the aligned condition than in the non-aliened condition irrespective of instruction types. In conclusion. attribute alignment in categorization may facilitate paying selective attention to categorization-relevant attributes.

• Journal of Science Education
• /
• v.43 no.2
• /
• pp.239-257
• /
• 2019

This study attempts to understand the context of shared learning in the trading zone formed by teachers from different backgrounds and the process in which this shared learning varies in the educational context, focusing on the case of 'Woodwork Science Education Study Group.' To do this, data was collected through in-depth interviews with eight teachers who participated in the 'Woodworking Science Education Research Group' and analyzed their responses based on grounded theory. As a result, the causal conditions of the teachers' research group were 'various contexts of entering the trading zone' and the central phenomenon was 'encounter with learning in the trading zone.' Contextual conditions affecting this phenomenon were 'woodwork as a boundary object and individual transfiguration experience,' and action/interaction strategy was 'various efforts and influences in the field.' The intervention condition was 'practical effort and experience in educational field.' Final result in this model is 'the new practice of learning shared in the trading zone.' In selective coating, it was found that the practice of the teacher's research group appears as four types of' 'Extracurricular creative experience type,' 'career education type,' 'curricula education type,' and 'school management type.' The results of this study suggest that the shared learning and antonymous practice among teachers in the teachers' research group as trading zone do not only meet their learning needs but also lead to various teaching practices in the individual teachers' context of education and improve the diversity and quality of education.

• Journal of Korean Academy of Dental Administration
• /
• v.5 no.1
• /
• pp.45-54
• /
• 2017

The purpose of this article is to cope with the abuse of antibiotics in the clinic, to determine the necessity of antibiotic administration, to share information on the selection and proper use of appropriate antibiotics, and to increase the appropriateness of antibiotic prescription through continuous monitoring. In line with the latest research and guidelines trends of various agencies, we will supplement the antibiotic prescription guidelines and use them for the treatment in Apple Tree Dental Hospital. Specially, by history taking and the penicillin allergy test, amoxicillin is prescribed as a primary selective antibiotic for 1 day. The complaints and treatment effects of the first antibiotic should be evaluated at the next visit. If the primary antibiotic was ineffective, we replaced it with a broad-spectrum antibiotic. If there was no improvement in symptoms, the patient would be referred to upper grade hospital. The staff of the Apple Tree Dental Hospital regularly monitored and educated antibiotic prescriptions. The current guidelines should be supplemented continually and positively affect the abuse of antibiotics and the habit of dental practice.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.210-210
• /
• 2013

그래핀은 뛰어난 기계적, 화학적, 광학적, 전기적 특성을 가지고 있는 2차원 물질로, 대면적 합성법과 전사 공정을 통해 다양한 기판에서의 사용이 가능해지면서 차세대 전자 소자로 활용하기위한 활발한 연구가 이루어지고 있다. 디스플레이, 태양전지의 전극과 전계 효과 트랜지스터의 채널로 적용한 연구에서 우수한 결과들을 보이고 있다. 특히, 금속/금속 산화물 전극은 염료 감응형 태양전지와 유기 발광 다이오드 구조에서 화학적으로 불안정할 뿐 아니라 일함수가 고정되어 쇼트키 접촉이 형성되면 저항을 낮추기 어렵지만, 그래핀은 금속/금속 산화물 전극보다 화학적으로 안정하고 일함수의 조절이 가능해 옴 접촉 형성에 용이하다. 그래핀의 일함수를 조절하는 연구는 크게 공유결합과 비공유 결합을 이용한 방법이 시도된다. 공유 결합을 이용한 방법은 합성과정에서 그래핀의 구조에 내재된 결함 혹은 새로운 결함을 형성하여 다른 원소를 첨가하는 방법이다. 이러한 방법은 그래핀의 결함 영역에서 작용하기 때문에 그래핀 전자 구조의 높은 수준 조절을 위해선 그래핀 구조의 파괴가 동반된다. 반면, 비공유 결합을 이용한 방법은 전하 이동 도핑 효과를 이용해 그래핀의 전자 구조를 제어하는 방법으로, 금속/금속산화물/기능기와 그래핀의 적층으로 복합 구조를 형성하는 방법이다. 금속/금속 산화물과의 복합구조는 안정적인 p-형 도핑이 보고되었지만, n-형 도핑은 대기중의 수분, 산소 그리고 기판과의 상호작용에 의해 대기중에서 불안정해 추가적인 피막공정이 요구된다. 기능기를 이용한 적층 구조는 그래핀과 기판사이의 상호작용 혹은 그래핀 전자 구조를 다양한 기능기를 이용해 제어하는 것으로, 이극성을 가진 자기정렬 단일층(self-assembled monolayers)이 대표적인 방법이다. 공간기(spacer)의 길이나 말단기(end group)의 종류로 p-형과 n-형의 도핑 수준을 제어할 수 있지만, 흡착기(chemisorbing groups)의 반응성이 기판의 화학적, 물리적 표면상태에 의존하기때문에 기판 선택이 제약되며 전처리 공정이 요구될 수 있는 한계가 있다. 본 연구에서는 다양한 기판에 적용가능한 용액 공정을 이용해 그래핀과 고분자를 적층하였고, 안정적이고 효과적으로 일함수를 낮추는 구조를 확인하였다.

• Environmental Mutagens and Carcinogens
• /
• v.9 no.1
• /
• pp.1-12
• /
• 1989

To study the selective organospecific carcinogenesis by the specific chemical carcinogens, the breast cancer induction model by oral administration of 7, 12-dimethylbenzanthracene (DMBA) or by intravenous injection of N-methylni-trosourea (NMU) on female rats was analyzed. In the present experiment, we compared the effexts of ages on the chemical mammary carcinogenesis by studying the metabolic system of the carcinogenic activation, detoxification or DNA damage and repair. The breast tumor incidence was significantly higher in the young rats of 50 days old than in those of one year old rats. As an index of organospecific DNA damage or repair, the in vivo covalent binding index(CBI) of the specific organs by the specific chemical carcinogens was monitored. And for the analysis of carcinogenic activation, the quantity of cytochrome P450`s was determined with the respective type-specific monoclonal antibody, while the detoxication capacity was deduced by the activity monitoring of glutathione S-transferase (GST) and peroxidase. The skin tissues of the mammary region had the highest CBI with both of DMBA and NMU at 50 days of age. And there were contrasting differences in the contents of carcinogenic activation and detoxication system: that is, the content of T.C.D.D.-inducible cytochrome P450 was high, while the activities of GST and peroxidase was low in the mammary skin tissues at tumor prevalent age. These results led us to conclude that the molecular organospecific carcinogenesis, as illustrated with mammary carcinoge-nesis by DMBA and NMU, is operated probably through the differential capacity of the target tissues in the high carcinogenic activation, low detoxication and the low DNA repair function.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.10
• /
• pp.39-44
• /
• 2008

Scan architecture is very effective design-for-testability technique that is widely used for high testability, however, it requires so much test time due to test vector shifting time. In this paper, an efficient scan test method is presented that is based on the Illinois scan architecture. The proposed method maximizes the common input effect via a scan chain selection scheme. Experimental results show the proposed method requires very short test time and small data volume by increasing the efficiency of common input effect.

• The Korean Journal of Pesticide Science
• /
• v.7 no.2
• /
• pp.155-158
• /
• 2003

2-Imino-1,3-thiazolines 1 show selective antifungal activity against pyricularia oryzae by new mode of action. A synthesis of novel 2-cyano-l,3-thiazolines 2 in which cyano moiety is substituted in imino group at C-2 of 1 is described. The lone pair electrons of sulfur and nitrogen as well as strong electron withdrawing cyano substituent in 1,3-thiazoline scaffold would effect the biological activity of 2-imino-1,3-thiazoline series. Regiospecific nucleophilic attack of thiourea 4 for $\gamma$-chloro-$\beta$-ketoacetoacetanilide 3 followed by acid catalyzed dehydration gave 2.