• 한국산학기술학회논문지
• /
• 제17권11호
• /
• pp.545-551
• /
• 2016

본 논문은 철도차량 안전의 핵심 요소인 제동성능을 확인하는 평가방법의 비교와 제동성능에 영향을 미치는 차륜과 레일의 마찰계수의 분포가 감속도에 미치는 영향을 분석하고 열차 편성에 따른 감속도의 분포를 예측하였다. 제동성능의 평가는 실제 운행중인 도시철도차량의 실차 시험을 통하여 제동시 제동거리와 제동시간을 측정해서 감속도를 산출하는 제동성능 평가방법과 UIC 544-1에 따른 제동중량비율을 이용한 평가 방법에 대하여 두 방법을 서로 비교하여 장단점을 살펴보았으며 각 방법의 호환성을 검토하였다. 차륜과 레일의 마찰계수 분포를 검토한 확률적 제동모델을 수립하고 제동성능에 가장 큰 영향을 미치는 차륜과 레일의 점착계수 분포가 열차의 편성에 미치는 영향을 분석하였다. 제동중량비율을 이용한 평가방법은 일정 초기 제동속도를 시험한 결과를 다양한 제동초기속도에서의 제동거리로 환산할 수 있어 열차 신호시스템의 설계나 신규 노선에서의 운전 패턴을 설계 검증할 수 있는 기초 자료로 활용이 가능할 것으로 보이며 편성에 따른 감속도의 확률적 분포 예측을 통하여 열차분리 결합등 가변 조성시 감속도의 분포를 예측함에 따라 보다 정밀한 열차신호 설계의 기초자료로 활용가능할 것으로 판단된다.

• Journal of applied mathematics & informatics
• /
• 제5권1호
• /
• pp.99-110
• /
• 1998

In this paper we study cyclic codes in $Z_m$. i.e., ideals in $Z_mG$, G afinite abelian group and we give a classification of such codes. We also sgtudy the minimum Hamming distance and the generalized Hamming weight of BCH codes over $Z_m$.

• 한국멀티미디어학회논문지
• /
• 제21권6호
• /
• pp.698-704
• /
• 2018

When the new ammunition is designed, it is necessary to confirm in advance how long the target distance is depends on the shape and weight of the designed ammunition. Therefore we can use commercial software such as PRODAS to predict the target distance in the design stage. This commercial software has aerodynamic data for various ammunition shape and calculates the target range by calculating the kinetic equations of the ammunition using the aerodynamic data most similar to the designed ammunition. The ammunition for predicting the target distance through software such as PRODAS is a non-guided ammunition that has no control after launch but the glide type ammunition is guided and control ammunition. So it is predicts the state of ammunition after the launch. A new type of simulator is needed to analyze the maximum range and to verify the onboard guided and control algorithm. The simulator constructed in this paper is an optimized simulator for glide type ammunition. Unlike unmanned aircraft and guided missiles. The rotation characteristics of the ammunition are considered and the navigation initialization algorithm is applied. The constructed simulator confirmed the performance by performing maximum range analysis of glide type ammunition.

• 한국해양공학회지
• /
• 제26권2호
• /
• pp.14-19
• /
• 2012

There are insufficient data to consider the effect zone for the marine life of coastal fisheries, because no standard has been defined for the sound level of marine life. In this study, equations for distance attenuation were used to determine the effect zone for oceanic noises. A reference noise level was divided into 4 parts to consider the characteristics of the fishes, and the effect zone of each reference noise level was determined. To increase the reliability of the effect scope, approximately 100 repetitions of blasting work split into several parts by the boring depth, the sound level of the source caused by an increase in weight, and the effect zone were calculated using the prediction equation. According to the prediction, the maximum distance of the effect zone was 4.92 km.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.311-317
• /
• 2007

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• 한국통신학회논문지
• /
• 제33권9C호
• /
• pp.704-711
• /
• 2008

본 논문은 효율적인 시각적 향상을 보여주는 새로운 비월 주사 방식 기법을 제안한다. 제안하는 알고리듬은 새로운 거리 가중치를 고려하며 이전에 개발되었던 EDI (Edge Dependent Interpolation) 알고리듬과 NAL (New Adaptive Linear interpolation) 알고리듬을 이용한다. 비월 주사 기법은 크게 2단계로 나된다. 우선 에지의 방향을 근접한 화소들의 정보를 이용하여 결정한다. 그리고 나서 잃어버린 화소 값들을 결정된 에지의 방향을 따라 보간 한다. 본 논문에서는 EDI 알고리듬을 통해 에지를 예측한 후에 NAL 알고리듬을 바탕으로 거리 가중치를 이용함으로써 잃어버린 화소들을 보간 한다. 실험 결과는 제안된 알고리듬이 기존의 알고리듬들보다 객관적 및 주관적인 평가에서 우수함을 입증한다.

• 한국연초학회지
• /
• 제10권2호
• /
• pp.93-98
• /
• 1988

This study was conducted to obtain basic information for varietal difference of leaf breakdown in field of flue-cured tobacco at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute in 1987. The experiment was designed in randomized block with 3 replications, data ware analysed as Split split-plot design. Main plots were varieties, sub-plots were leaf positions, 4, 5 and 6th from bottom, and each sub-plot was divided into 3 parts with distance of midrib, 7 10 and 13em from stalk. Four varieties, NC 95, NC 2326, NC 82 and BY 4 were transplanted in 15 April, and measured the weight of leaf breakdown by artificially weighted in 5 June. The results obtained are as follows : 1. Weights of leaf breakdown according to leaf position, NC 95 were lower as 358-5799 than those of other varieties as 555-597g, were not significantly different regardless of varieties. 2. Weights of leaf breakdown in relation to distance of midrib from stack, NC 95 were lower as 309-419g than those of other varieties as 472-710g. 3. Weights of leaf breakdown were significantly different according to distance of midrib from stalk, and not significantly different according to leaf position under the same distance of midrib from stalk regardless of varieties.

• 보건교육건강증진학회지
• /
• 제24권5호
• /
• pp.69-85
• /
• 2007

연구목적: 본 연구는 1999년과 2005년의 다른 코호트에 있는 아동과 청소년 집단의 신체발육 특징을 비교분석함으로써 한국 아동과 청소년 신체발육의 단기적 시대변화를 파악하고자 하였다. 연구방법: 1999년 서울시 고등학교에 재학한 16세 남학생 231명, 여학생 346명과 2005년 서울시 고등학교에 재학한 16세 남학생 171명과 여학생 400명을 대상으로 이들의 건강검사 기록을 통해 종단적 신체발육자료를 수집하여 비교분석하였다. 연구결과: 주요 연구결과는 다음과 같다. 첫째, 남학생과 여학생 6세에서 16세까지의 모든 학생들의 2005년도 신장, 체중, 좌고, 흉위가 1999년에 비하여 더 컸다. 따라서 비교적 짧은 기간 동안에도 발육과정에 긍정적인 변화가 있음을 알 수 있었다. 둘째, 체중의 발육속도는 peak age이전이나 이후 모두 2005년이 컸으나, 신장은 peak age 이후에만 유의하게 컸다. 셋째, 2005년의 남학생들은 1999년에 비하여 신장은 평균 0.28년, 체중은 1.02년, 좌고는 0.39년, 흉위는 0.93년 앞서 있는 것으로 나타났다. 여학생의 경우, 신장은 0.81년, 체중은 0.76, 좌고는 0.32, 흉위는 0.57년 2005년이 앞서있었다. 즉, 2005년의 남학생들은 1999년에 비해 0.28-1.02년, 여학생들은 0.32-0.81년 발육이 앞서 있었다. 넷째, peak velocity에서만 남학생, 여학생 모두 유의한 시대적 변화가 있었고, peak age에서는 시대적 변화가 발견되지 않았다. 다섯째, BMI, 체중, 좌고, 흉위관련 지표에서 시대적 변화가 발견되었다. 특히 남학생의 경우는 체중, BMI, 흉위 관련지표에서, 여학생은 체중, 좌고에서 2005년과 1999년 간 유의한 차이가 발견되었다.

• The Korean Journal of Ecology
• /
• 제20권1호
• /
• pp.51-59
• /
• 1997

To investigate the distribution of heavy metal concentrations in Onsan bay, concentrations of cadmium, copper, zine and lead in surface sediments and the periwinkles (Littorina brevicula) were determined in Feburary and July, 1996. The ranges of cadmium, copper, zinc and lead concentrations in the surface sediments were 0.08-3.72, 3-307, 49-1273 and 15-399 ${\mu}g/g$ dry weight, respectively, The decrease of concentration in heavy metals with distance from Daejeong stream indicated that this stream is the pollutant source of heavy metals in Onsan Bay. The concentrations of cadmium, copper, zinc and led in L. brevicula were 0.11-11.81, 21-212, 30-96 and 0.26-4.12 ${\mu}g/g$ dry weigth in February and 1.01-24.9, 66-325, 54-225 and 0.68-8.41 ${\mu}g/g$ dry weight in July, respectively. These concentrations in L. brevicula were the significantly different (p<0.001) with the season of sampling. However, overall distribution of concentrations of heavy metals in L. brevicula had very similar tendency that concentrations of heavy metal decreased with the distance from the pollutant source irrespective of the two seasons. Therefore, L. brevicula is considered as a useful indicator for heavy metals pollution, According to analysis of the organs, tissues such as the digestive gland, gill and viceral mussel accumulate high concentrations of heavy metals.

• 한국초지조사료학회지
• /
• 제9권2호
• /
• pp.77-81
• /
• 1989

This experiment was conducted to elucidate the changes of dry matter production in permanent pasture and its relation with relative yield of the 1st cutting, regrowth capacity, and persistance of orchardgrass sward, based on the data of preceeding The results were summarized as follows; 1. Relationship between relative yield of the 1st cutting and regrowth capacity were changed by the times of established pasture. Thus, the relative yield of the 1st cutting have negative significant correlation (P < -0.001) with regrowth capacity. 2. Regrowth capacity(RC) was positively significant correlations with the dry weight of plant (DW/pl.), number of tillers per plant (NT/pl.), plant size(PS) and distance between adjacent plants (DIS) of the 1st cutting. Also, regrowth capacity(RC) was positively correlations with the dry weight of plant (DW/pl.), number of tillers per plant (NT/pl.), stubble diameter(DIA), stubble area(SB), plant size(PS) and distance between adjacent plants(D1S) of the 2nd cutting. 3. The coefficients of regression of the 1st cutting showed a tendency to slightly decrease, on the other hand, the 2nd cutting and total yield were tended to increase by the times of established pasture. 4, Between the regrowth capacity and persistency were may deeply concerned to the changes of dry matter production in permanent pasture. 5. The process of dry matter production in permanent pasture can be shown in following diagrams.