• The Journal of Engineering Geology
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• v.27 no.2
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• pp.165-172
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• 2017

This research aims to define influence factors to perform an optimized section design and evaluate tunnel collapse risk during construction using Delphi technique. A total of five upper classification systems were constructed through literature review, pervious research analysis, and brainstorming of expert group for establishing influence factors. The $1^{st}$, $2^{nd}$, and $3^{rd}$ Delphi survey process was proceeded by panel group which is consisted 21 experts to prevent errors and bias in the expert judgement process. In Delphi $1^{st}$ survey, a total of 22 influence factors candidates were derived through open-ended questionnaire. In Delphi $2^{nd}$ survey, questionnaire was proceeded based on 7-point Likert scale method. In order to verify the validity, CVR (Content Validity Ration) analysis was performed to exclude inappropriate candidates. In the $3^{rd}$ survey, verification of influence factors was proceeded once more with the result of $2^{nd}$ survey, and lastly, a total of 14 influence factors was derived by CVR and COV (Content Validity Ration) analysis for response of experts.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.12
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• pp.471-480
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• 2016

Recently, the damage of cyber attack toward infra-system, national defence and security system is gradually increasing. In this situation, military recognizes the importance of cyber warfare, and they establish a cyber system in preparation, regardless of the existence of threaten. Thus, the study of Intrusion Detection System(IDS) that plays an important role in network defence system is required. IDS is divided into misuse and anomaly detection methods. Recent studies attempt to combine those two methods to maximize advantagesand to minimize disadvantages both of misuse and anomaly. The combination is called Hybrid IDS. Previous studies would not be inappropriate for near real-time network environments because they have computational complexity problems. It leads to the need of the study considering the structure of IDS that have high detection rate and low computational cost. In this paper, we proposed a Hybrid IDS which combines C4.5 decision tree(misuse detection method) and Weighted K-means algorithm (anomaly detection method) hierarchically. It can detect malicious network packets effectively with low complexity by applying mutual information and genetic algorithm based efficient feature selection technique. Also we construct upgraded the the hierarchical structure of IDS reusing feature weights in anomaly detection section. It is validated that proposed Hybrid IDS ensures high detection accuracy (98.68%) and performance at experiment section.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.8
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• pp.379-384
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• 2017

In real software business environment, there are required to validate software quality in diverse usage range of software for many small & medium companies. Software quality means both qualities of production and process. In our situation, we focus on better process quality of a test organization than a whole organization. But even the original test maturity model (TMM) does not enough to apply with our domestic venture/small & medium companies. To solve this problem, we suggest the simplified test maturity model for our companies. We redefine this simplified model with the original TMM and a test process improvement next (TPI next) model. The previous models just have provided each definition of maturity level, goal and activity per each level, which not exists an assessment guideline and a formal assessing procedure. Due to this reasons, an assessor is difficult to assess the test organization without them. this paper suggest an assessment guideline of the simplified TMM and also define the procedure which is included with activities and byproducts. With these assessment guideline, an assessor can work possible to formally assess test organizations of small & medium companies, and with self assessment guideline they can be correctly provision before assessment of their organizations.

• Korean Security Journal
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• no.42
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• pp.37-57
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• 2015

The purpose of this study was to verify goodness-of-fit by Many-Facets Rasch model for applying martial arts training satisfaction scale to security martial arts trainees. To achieve the purpose, 255 security martial arts trainees' data were used in the analysis. In addition, In addition, the AMOS 20.0 program was used for unidimensionality validation, and take advantage of the Facets 3.61 program for goodness-of-fit verification. Specific results are as follows: First, Unidimensionali test results showed that model fit, reliability and standardized ${\beta}$ value are suitable. Second, the analysis results of goodness-of-fit, items 1, 2, 3 are inadequate, 4, 8, 11, 13, 14 items once found to be over-fit questions. Also, analysis of item difficulty, item 1 has highest difficulty and item 7 was lowest. Third, According Facets item difficulty and response difference verification result, female group exhibited a high level of item difficulty compared to the male group, goodness-of-fit was all accurate. As the result of item difficulty and response difference verification based on Martial arts training flow, there is no response difference according to the training experience. On the other hands, less than 4 years to 5 years and less than 5 years to 6 years trainees represented over-fit features. Results of item difficulty and response difference verification by grade level, first grade was the most highly recognized the item difficulty and fourth grade was also recognized the lowest of item difficulty Fourth, the response category analysis showed that the six points response categories are not appreciate.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.253-258
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• 2005

It is necessary to determine a nitrogen supplying capacity (NSC) of soil for sustainable agriculture. NSC has been decided by directly detecting N mineralization potential (NMP) and inorganic nitrogen or by indirectly approximating from organic matter and chemical properties of soil. NMP is best method for NSC but it takes long period. A study was conducted to find a short-term incubation method using pepsin through 1) determining NMP of 3 upland and 3 paddy soils, 2) establishing analytical condition of pepsin digestion by comparing to NMP, 3) validating with relations to N requirements for maximum yield of rice. NMPs of 6 soils were ranges from $63mg\;N\;kg^{-1}$ to $156mg\;N\;kg^{-1}$. The pepsin digestion method of soil nitrogen was established by determining amino nitrogen from digesting 5 g of soil for 30 minutes by 0.02% pepsin. This method was so highly correlated with a maximum rate of nitrogen fertilizer that it could be used for determining NSC in paddy soil.

• Journal of Korean Society of Transportation
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• v.21 no.3
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• pp.15-22
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• 2003

In general, the linear regression model has been used to estimate trip generation in the travel demand forecasting procedure. However, the model suffers from several methodological limitations. First, trips as a dependent variable with non-negative integer show discrete distribution but the model assumes that the dependent variable is continuously distributed between -$\infty$ and +$\infty$. Second, the model may produce negative estimates. Third, even if estimated trips are within the valid range, the model offers only forecasted trips without discrete probability distribution of them. To overcome these limitations, a poisson model with a assumption of equidispersion has frequently been used to analyze count data such as trip frequencies. However, if the variance of data is greater than the mean. the poisson model tends to underestimate errors, resulting in unreliable estimates. Using overdispersion test, this study proved that the poisson model is not appropriate and by using Vuong test, zero inflated negative binomial model is optimal. Model reliability was checked by likelihood test and the accuracy of model by Theil inequality coefficient as well. Finally, marginal effect of the change of socio-demographic characteristics of households on trips was analyzed.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.10-10
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• 2003

일라이트-스멕타이트 혼합층광물(I-S)은 열역학적으로 상호 대립적인 두 가지 모델로 이해되고 있다. 첫째, MacEwan 결정자 모델은 I-S를 5-20개의 스멕타이트와 일라이트 층으로 구성된 결정자로 해석한다. 이러한 모델은 분산과 재응집 과정을 기초로 하는 X-선 회절분석(XRD)에서 기인한 것으로 Reynolds의 XRD 모델과 동일하다. 둘째, 기본입자 모델은 I-S를 물리적으로 분리될 수 있는 최소 입자인 기본입자가 $c^{*-}$축 방향으로 응집된 응집체로 해석한다. 이러한 모델은 분산 과정을 기초로 하는 주사전자현미경(TEM) 관찰에서 기인한 모델이다. 강일모 등(2002)은 이 두 가지 모델을 비교함으로써 1< $N_{F}$<100/% $S_{XRD}$ ( $N_{F}$=평균 기본입자 층개수, %$S_{XRD}$=XRD 분석을 통하여 측정된 팽창성)을 도출하였다. 이 식은 기본입자모델과 Eberl & Srodon(1988)이 제시한 최대 팽창성(%$S_{MAX}$)을 동시에 해석할 수 있게 해준다. %$S_{MAX}$는 XRD 모델에서는 고려하지 않는 I-S 결정자 상$\cdot$하부에 존재하는 두 개의 0.5nm 규산염층을 하나의 스멕타이트 층으로 간주하여 얻어진 팽창성이다. Srodon et al.(1992)은 %$S_{MAX}$=100/ $N_{F}$을 제시하였으며, 강일모 등(2002)은 %$S_{MAX}$는 기하학적으로 기본입자가 무한적층을 하였을 때 관찰되는 %$S_{XRD}$와 동일함을 밝힌 바 있다. 만약, XRD 분석을 위한 시료 준비과정에서 I-S 결정자가 분산되었다가 재응집을 한다면, XRD에서 관찰되는 결과는 일차적으로 기본입자의 적층성에 영향을 받게 된다. 따라서, 기본 입자의 적층성은 XRD 분석을 이용하여 I-S 구조를 해석하는데 매우 중요한 요인이다. 본 연구는 기본입자의 적층성을 정량화하기 위해 %$S_{XRD}$=A/ $N_{F}$ (0$S_{MAX}$=100/ $N_{F}$로부터 얼마나 벗어나 있는가는 지시해 준다 금성산화산암복합체에서 산출되는 11개 I-S 시료와 14개의 Drits et al.(1998) 자료로부터 1nA=-0.14 $N_{F}$+4.7의 실험식을 도출할 수 있었으며, 기본입자의 적층성은 일차적으로 기본입자의 두께에 의해 영향을 받는 것으로 관찰되었다. Nadeau(1985)는 기본입자두께분포로부터 I-S 결정자의 팽창성을 측정하기 위하여 Ps=$\Sigma$p(N)/N을 제시하였다(Ps=스멕타이트 층 비율, N=기본 입자 층개수, p(N)=N의 확율). 그러나 위식은 실질적으로 %$S_{MAX}$를 제공해주기 때문에 %$S_{XRD}$를 유추하는데는 부적합하다. 본 연구는 이를 변형하여 Ps=$\Sigma$p(N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%$S_{XRD}$)의 기본입자분포로부터 %$S_{XRD}$를 계산한 결과, 16%$S_{XRD}$의 결과값을 얻을 수 있었다. 따라서, 본 연구에서 도출한 관계식들이 유효함을 확인할 수 있었다.계식들이 유효함을 확인할 수 있었다.

• Research in Mathematical Education
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• v.7 no.3
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• pp.139-150
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• 2003

The purpose of this paper is to review the gifted education from a reflective perspective. Especially, this research touches upon the issues of selection process from a critical point of view. Most of the problems presented in the mathematics competition or in the programs for preparing such competitions share the similar characteristic: the circumstances that are given for questions are too artificial and complicated; problem solving processes are superficially and fragmentally related to mathematical knowledge; and the previous experience with the problem very much decides whether a student can solve the problem and the speed of problem solving. In contrast, the problems for selecting students for Gifted Education Center clearly show what the related mathematical knowledge is and what kind of mathematical thinking ability these problems intend to assess. Accordingly, the process of solving these problems can be considered an important criterion of a student's mathematical ability. In addition, these kinds of problems can encourage students to keep further interest, and can be used as tasks for mathematical investigation later. We hope that this paper will initiate further discussions on issues derived from the mathematically gifted student selection process.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.175-182
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• 2010

Differences in physiochemical characteristics of row waxy rice, steeped in optimum steeping conditions ($31.5^{\circ}C$, 9 days) were investigated along with the relationship between these properties and the quality characteristics of Gangjung made from ten different varieties of waxy rice in order to identify the optimal waxy rice variety for making Gangjung. The moisture content of ten waxy rice varieties was increased, but protein and ash contents were decreased during steeping. Mineral analysis, showed that the Fe, Mg, Ca, Na and K contents of all samples were decreased during steeping. Regarding the gelatinization behavior of the ten waxy rice varieties, the peak viscosity and breakdown were increased with the exception of Backjinju and Backjinju-1 during steeping. Shinsunchalbyeo was the most adaptable waxy rice variety for making Gangjung, as its tested scores for expansion ratio and crispness were higher than other waxy rice varieties. The textural properties of Gangjung made from Backjinju and Backjinju-1 had the highest levels of hardness and showed the lowest expansion ratios. Therefore, Backjinju and Backjinju-1 are considered the worst varieties for making Gangjung.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.288-294
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• 2014

Penicillin and its salts, including the benzatine, procaine, and sodium salts, have been widely used in human and veterinary medicine. Owing to their low toxicity, they currently form the most important group of antibiotics. However, overdose and abuse of these antibiotics may lead to potential risk in human health. Therefore, this study was conducted to validate the analysis method established by the Korea Food Code in 2012 and to monitor the levels of benzylpenicillin residues in products with reference to the maximum residue level (MRL). Of the 232 product samples tested, benzylpenicillin was detected in 11 livestock products and 2 marine products. Benzylpenicillin concentrations were found to be lower than the MRL in 12 products; however, the concentration of benzylpenicillin was found to be greater than the MRL in 1 pork product. The limit of quantification (LOQ) for benzylpenicillin was found to be 0.001-0.002 mg/kg, with an average recovery of 90.4-115.3%. Calibrations showed good linearity of 0.995 over a range of 0.002-0.05 mg/kg.