• 대한수학교육학회지:수학교육학연구
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• 제8권2호
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• pp.527-540
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• 1998

In the teacher's guide of mathematics textbook for the 1st grade of the middle school, the clear and logical reason why the multiplication of negative number to negative number makes positive number, and $a^{-m}$ with a>0 and m>0, is defined by ${\frac{1}{a^m}}$ is not given. When we define the multiplication or the power by successive addition or successive multiplication of the same number, respectively, we encounter this ambiguity, in the case that the number of successive operations is negative, In this paper, we name this number, negative counting number, and we make the following more logical and intuitive definition, which is "negatively many successive operations is defined by positively many successive inverse operations." According to this new definition, we define the multiplication by the successive addition or the successive subtraction of the same number, when the multiplier is positive or negative respectively, and the power by the successive multiplication or the power is positive or negative, respectively. In addition, using this new definition and following the E.R.S Instruction strategy which revised and complemented the Bruner's E.I.S Instruction strategy, we develope new teaching model available in the 1st grade class of middle school where the concept of integers, three operations of integers are introduced.ntroduced.

• East Asian mathematical journal
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• 제30권3호
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• pp.355-360
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• 2014

Let D be a finite digraph with the vertex set V (D) and the arc set A(D). A function f : $V(D){\rightarrow}\{-1,\;1\}$ defined on the vertices of a digraph D is called a bad function if $f(N^-(v)){\leq}1$ for every v in D. The weight of a bad function is $f(V(D))=\sum\limits_{v{\in}V(D)}f(v)$. The maximum weight of a bad function of D is the the negative decision number ${\beta}_D(D)$ of D. Wang [4] studied several sharp upper bounds of this number for an undirected graph. In this paper, we study sharp upper bounds of the negative decision number ${\beta}_D(D)$ of for a digraph D.

• 대한수학회보
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• 제54권6호
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• pp.2149-2154
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• 2017

In this paper, we obtain a simple lower bound for the number of positive (resp. negative) crossings in oriented link diagrams in terms of the maximal (resp. minimal) degree of the Jones polynomial.

• 대한의료기공학회지
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• 제20권1호
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• pp.148-162
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• 2020

Objective : The purpose of this study is not only to examine the negative functions of alcohol, but also to examine the positive functions and look at it with a balanced perspective. Methods : We investigated the number of times the word "酒"(alcohol) appears in 《Hwangjenaegyeong》 and 《Gyeongakjeonseo》. The meaning of alcohol was divided into seven categories. The number of positive and negative functions of alcohol was counted and the ratio was calculated. Results : 1. In the 《Hwangjenaegyeong》, the word alcohol appears 23 times, of which 9 times has positive functions, 10 times has negative functions, and the remaining 4 times does not correspond anywhere. The ratio of positive functions is 39.13% and negative functions 43.48%. 2. In the 《Gyeongakjeonseo》, the word alcohol appears 1,487 times, of which 1,140 times (76.66%) has positive functions, and 327 times (21.99%) has negative functions. Conclusions : 1. In 《Hwangjenaegyeong》, the number of comments about positive and negative functions of alcohol is similar. 2. 《Gyeongakjeonseo》 has commented a lot about the positive functions of alcohol. However, it has more mentions to negative functions of alcohol except for those related to herbs and prescriptions (48 to 64 chapter). 3. It is somewhat unreasonable to judge the emphasis on the positive and negative function of alcohol according to the number of references to alcohol in oriental medicine classics. But in these books, we can find a balanced approach between the two sides, not a one-sided biased view. 4. From a curative point of view, it is desirable to know and to use the positive and negative functions of alcohol, and drink alcohol as appropriate control.

• 한국항만경제학회지
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• 제25권2호
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• pp.57-72
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• 2009

본 논문에서는 국내 13개 항만을 대상으로, 정상DEA 제1모형에서는 2개의 산출물(수출입 물량, 선박입출항척수)과 2개의 투입물(접안능력, 하역능력), 제2모형에서는 4개의 투입물(접안능력, 하역능력, 경비함정수, 특수함정수)과 2개의 산출물(수출입물량, 선박입출항척수)을 이용하여 전통적인 투입지향, 가변규모수확조건하에서 분석을 통해 상대적인 효율성을 측정하였으며, 기존연구의 한계를 확장시키기 위해서 국내 항만분야에서는 처음으로 Negative DEA분석(산출지향, 가변규모수확조건, 투입요소: 수출입물량, 선박입출항척수, 산출요소: 해양사고, 해상범죄, 해양오염사고)을 통해서 항만운영에 위험이 되는 산출요소를 반영하여 가장 효율적인 항만들이 가장 운영위험이 큰 항만들임을 실증분석을 통해서 보여 주었다. 주요한 실증분석 결과는 다음과 같다. 첫째, 정상 DEA모형에서 운영효율성이 가장 낮은 동해항은 여수항, 부산항, 울산항들의 운영방법을 중-장기적인 측면에서 벤치마킹해야만 한다. 둘째, Negative DEA모형에서 가장 운영위험이 높은 항만들은 태안, 여수, 통영, 부산, 속초항으로 나타났다. 본 연구의 정책적인 함의는 다음과 같다. 즉, 첫째, 항만운영에 관여하는 정책입안가들은 본 연구에서 사용한 정상DEA모형에 의해서 비효율적인 항만들은 단기 중기 장기적으로 벤치마킹항만들의 운영방법을 추구해야만 한다. 둘째, Negative DEA분석을 통해서 가장 운영위험이 높은 항만은 5개 항만인 것으로 나타났다. 즉, 태안, 여수, 통영, 부산, 속초항들이다. 따라서 이러한 항만들은 중-장기적으로는 2층 효율성 분석에서 효율적이지 않은 것으로 나타난 인천, 울산, 포항, 동해항을 벤치마킹해야만 한다. 본 논문의 한계점은 Simak(2000)이 제시한 것과 같은 다양한 방법과 다년도분석법을 사용하여 항만들의 운영위험을 예측하는 측정을 했어야만 했지만 자료수집의 문제점 때문에 그렇게 하지 못하였다. 차후연구에서는 그러한 방법을 다루고자 한다.

• 한국연초학회지
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• 제22권1호
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• pp.31-38
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• 2000

Seven flue-cured tobacco(Nicotiana tabacum) varieties and their 21 progenies in Fl and F2 generation, half diallel crosses(no reciprocal), were tested for the degree of heterosis and combining abilities in sucker producing character according to topping and suckering treatment. Significant difference in number and weight of sucker was observed among seven cultivars. The values of general combining ability(GCA) were greater than those of specific combining ability(SCA) in weight and number of sucker in F$_1$ generation. In topping and suckering plot, Cocker 86, McNair 944, and Va 115 revealed the significant negative GCA effects for number and weight of sucker, but By 104 and Speight G-28 did positive GCA. Without topping and suckering, GCA effects for sucker weight in Cocker 139 and Cocker 86 were negative and those for sucker number in Va. 115 were also negative. Negative SCA values in sucker weight could be observed in F$_1$ generation of Cocker 86 X BY 104 and Speiht G-28 X Cocker 86, in F$_2$ of Hicks $\times$ Speight G-28 and McNair 944 $\times$ BY 104 in topping and suckering plot. SCA in F$_1$ of McNair 944 X Cocker 86 and Speight G-28 X Cocker 139 was negative without topping and suckering. The value of heterosis in sucker producing character of F$_1$ hybrids was positive

• 대한수학교육학회지:수학교육학연구
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• 제13권1호
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• pp.25-55
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• 2003

In the school mathematics, the negative numbers have been instructed by means of intuitive models(concrete situation models, number line model, colour counter model), inductive-extrapolation approach, and the formal approach using the inverse operation relations. These instructions on the negative numbers have caused students to have the difficulty in understanding especially why the rules of signs hold. It is due to the fact that those models are complicated, inconsistent, and incomplete. So, students usually should memorize the sign rules. In this study we studied on the didactical phenomenology of the negative numbers as a foundational study for the improvement of teaching negative numbers. First, we analysed the formal nature of the negative numbers and the cognitive obstructions which have showed up in the historic-genetic process of them. Second, we investigated what the middle school students know about the negative numbers and their operations, which they have learned according to the current national curriculum. The results showed that the degree they understand the reasons why the sign rules hold was low Third, we instructed the middle school students about the negative number and its operations using the formal approach as Freudenthal suggest ed. And we investigated whether students understand the formal approach or not. And we analysed the validity of the new teaching method of the negative numbers. The results showed that students didn't understand the formal approach well. And finally we discussed the directions for improving the instruction of the negative numbers on the ground of these didactical phenomenological analysis.

• Journal of Yeungnam Medical Science
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• 제2권1호
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• pp.183-190
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• 1985

본 시안(MCRCODE-N)은 말 그대로 시안인 바 많은 수정과 첨가가 필요할 것이라고 생각되나 국내 실정에 맞는 검사법이라고 생각된다. 본 시안을 이용하여 결정을 보완하는 일이 시급한 바 동학 선후배의 지도 편달을 바라는 바 이다.

• 대한인간공학회지
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• 제11권1호
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• pp.21-29
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• 1992

A study on analyze the effect of positive and negative contrast for user performance on the VDT tasks);text typing, text deiting, and searching task) has been performed. The performances were measured in terms of the completion time and the number of errors. The results of each VDT task are followings. In the text typing task and the searching task, the performances measured by the number of errors were better at the condition of negative contrast than at that of positive contrast. In the text deiting task, the performance showed a reverse tendency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1737-1739
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• 1998

The paper presents experimental results of Partial Discharge(PD) in Gas Insulated Switchgear(GIS), obtained using a computer-aided PD measurement system. Different discharge sources are simulated and identified. These included internal, interface, surface and protrusion. For internal discharge, it showed symmetrical discharge type between positive and negative cycle. Interface discharge showed smaller number and higher peak than internal discharge but symmetrical discharge as well. For surface discharge, it showed small number and high peak in positive half cycle but large number and low peak in negative half cycle. For protrusion discharge, small number and high peak of discharge were shown only in negative half cycle.