• 한국사회정책
• /
• v.23 no.3
• /
• pp.17-47
• /
• 2016

This paper aims to analysis working-time of Korea focusing on "the difference and the distribution" by a stratum. Classifying working-time into four categories including marginal part-time, part-time work, standard-time work and long-time working, it compares the relative distribution by income quintile. The outcome is as following : 20% of low-ranking income quintile are (marginal) part-time working, 60% from income quintile 2 to 4 are in long-time working and 20% of top-ranking income quintile are in the standard-time working in overall. Working-time classes can be divided up into three: short time-low income of type 1, long time-medium income of type 2 and standard time-high income of type 3. Analysing working time type, the low wage-short time, medium wage-long time and high wage-standard time by the wage per month and low wage-very long time, medium wage-long time and high wage-standard time by the wage per hours are confirmed. Also, stratification of working-time has been intensified in terms of age, jobs and work status. Policy implication from this study is that the increase of minimum wage to the lowest income class and creation of employment by the reduction of working-time to the medium income class could be effective policies.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.18 no.3
• /
• pp.17-25
• /
• 2014

The purpose of this paper is to present a method to estimate the storage life of propellant bag for degradation of breaking load with storage time by using gamma process model. The nitrogen compound generated by natural decomposition of propellants degrades the breaking load of propellant bag with time. The statistical distributions of condition and lifetime with time were shown from the results of accelerated life test of propellant bag cloth at $80^{\circ}C$. It was found that the use of median for life was highly appropriate and the $B_1$ or $B_5$ life should be selectively applied to the quality assurance policy.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.113-113
• /
• 2023

기후변화로 인한 온도 상승이 대기 중 수분량을 증가시키면서 극한 강우가 전 세계적으로 빈번하게 발생하고 있으며, 이에 따라 대규모 홍수 피해가 지속적으로 초래되고 있다. 본 연구에서는 이러한 현상에 대응하기 위한 노력으로, 대기 연직 기둥 내 총 수분량을 나타내는 총가강수량(Total Precipitable Water, TPW)과 극한 강우사상(Extreme Precipitation, EP) 간의 연관성이 강우지속기간에 따라 어떻게 변하는지 분석하였다. 관측 및 재해석(reanalysis) 데이터를 활용하여 동시극한지수(Concurrent Extremes Index, CEI, 0~1, 1에 가까울수록 강한 연결)로 두 변수 간의 정량적 연결 강도를 살펴보았다. 분석 결과, CEI의 지속 시간에 따른 변동 경향성은 지역에 따라 상당한 차이를 보였다. 지중해와 중앙아시아와 같은 대부분의 중위도 지역에서는 강우의 지속 기간이 길어질수록 CEI 값이 급격히 감소하였다. 그러나 한반도를 포함한 동아시아 지역은 중위도임에도 불구하고 긴 지속 기간의 강우 사상에서도 높은 수준의 CEI 값을 유지하였다. 이러한 동아시아 지역의 경향성은 열대지역과 매우 유사하게 나타났으며, 이는 동아시아 지역의 극한 강우 증가가 기후변화의 직접적인 영향을 받을 수 있음을 시사한다.

• Journal of Digital Contents Society
• /
• v.17 no.5
• /
• pp.375-381
• /
• 2016

Recently, a foreground-background segmentation using codebook model has been researched actively. The codebook is created one for each pixel in the image. The codewords are vector-quantized representative values of same positional training samples from the input image sequences. The training is necessary for a long time in the most of codebook-based algorithms. In this paper, the initial codebook model is generated simply using median operation with several image frames. The initial codebook is updated to adapt the dynamic changes of backgrounds based on the frequencies of codewords that matched to input pixel during the detection process. We implemented the proposed algorithm in the environment of visual c++ with opencv 3.0, and tested to some of the public video sequences from PETS2009. The test sequences contain the various scenarios including quasi-periodic motion images, loitering objects in the local area for a short time, etc. The experimental results show that the proposed algorithm has good performance compared to the GMM algorithm and standard codebook algorithm.

• Communications of Mathematical Education
• /
• v.18 no.2 s.19
• /
• pp.441-451
• /
• 2004

수학의 내용을 학생에게 지도할 때 기계적인 계산법칙을 가르치는 것보다 개념을 이해할 수 있도록 돕는 것은 교사의 중요한 역할이다. 그 동안 연구를 통해 정수를 지도하기 위한 모델들은 꽤 많이 알려져 왔으나 이 모델들을 학생에게 직접 적용하였을 때 일어나는 현상을 파악한 연구는 그리 많지 않다. 따라서 본 연구는 상위, 중위권 초등학교 5학년을 대상으로 EIS이론에 바탕을 둔 정수의 모델을 통해 학생들이 정수의 개념을 어떻게 형성하고 그 과정에서 어떤 오류를 나타내는지, 또 무엇을 가장 어려워하는지 등 그 학습과정을 조사하였다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.1
• /
• pp.1-6
• /
• 2004

Agricultural recycling of livestock wastes by composting has lots of beneficial effects on crop production and soil fertility. Most of composts are made from pig manure and water content controller such as saw dust, bark, rice hulls etc. by aerobic processing. But the insufficient supply of saw dust, bark etc. cause the indiscreet use of industrial waste having heavy metals and toxic synthetic chemicals. This research investigated the present quality status of organic by-product fertilizers, and suggested the way of quality interpretation under the statistical approaches based on median, mean and weighted average value. Since the data of one hundred of samples for heavy metal contents (Cd, Pb, Cu, and Cr) and OM/N showed extremely left-skewed distribution, the median was more useful than the mean in representing the characteristics of distribiition for each items. The weighted average value will be a useful index for the quality based on the total amount of producing.

• The Journal of the Korea Contents Association
• /
• v.15 no.7
• /
• pp.343-352
• /
• 2015

This purpose of this study was to identify view of occupational therapy fieldwork supervisor and novice occupational therapists in job. 117 fieldwork supervisor and 104 novice occupational therapists that work on 58 domestic hospitals were chosen. The collected data were analyzed by using the SPSS 20.0 statistics package for Window which determined frequency, percentage, mean, standard deviation, median, and range. The following are the results of this study. First, fieldwork supervisor considered that basic refinement and manners are most important when they evaluate student. Second, novice occupational therapists responded that importance is 10 points, conduction is 7 points, and satisfaction is 6 points in general job. Third, importance of fieldwork supervisor for the job were problem identification and established intervention plan in intervention plan appears over the first 2 above. But, conduction of novice occupational therapists for the job were evaluation in all 4 of the top 5 except 2 place. The results of this study are expected to be used as direction guidance of fieldwork to the solve difficulty of novice occupational therapists.

• Journal of the Korean Institute of Telematics and Electronics T
• /
• v.35T no.2
• /
• pp.13-19
• /
• 1998

The Median of a set of number is a number which partitions the given set. The specified numbers of a set partitions in one subset and in another subset. In Image Processing, The Sorting method of numbers of one subset equal to the previous Median Filtering. but The Sorting method of numbers of another subset not equal to in the other. In this paper, a fast two-dimentional Median Filtering Algorithm is proposed. The Algorithm designed in such a during the partitioning of the previous window are used. Test results obtained by running the Algorithm on IBM PC(586) are presented and its filtering. It is shown that the proposed Algorithm's processing time is faster and independent of the number of bits used to represent the data values.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.11
• /
• pp.1245-1256
• /
• 2014

The physical nature of fatigue shows the considerable amount of scatter from intrinsic and extrinsic factors. In this study, some degradation models, such as the gamma process model, were reviewed in terms of uncertainties associated with the continuous, gradual, and monotonic nature of fatigue crack growth. Statistically varying fatigue crack growth data obtained from Lu and Meeker were used as an example to demonstrate the use of the gamma process model. This model can describe the condition and lifetime as statistical distribution curves whose shapes vary with cycles. From the skewness of the statistical distribution curves, it was confirmed that the median is suitable for being considered as the expected life. The use of the gamma process model enables the optimum replacement period and percentile life to be employed as criteria for preventive maintenance policy.

• The KIPS Transactions:PartB
• /
• v.14B no.7
• /
• pp.549-558
• /
• 2007

Collaborative filtering systems have problems when users rate items and the rated results depend on their feelings, as there is a possibility that the results include noise. The method proposed in this paper optimizes the matrix by excluding irrelevant ratings as information for recommendations from a user-item matrix using dispersion. It reduces the noise that results from predicting preferences based on original user ratings by inflecting the information for items and users on the matrix. The method excludes the ratings values of the utmost limits using a percentile to supply the defects of coefficient of variance and composes a weighted user-item matrix by combining the user coefficient of variance with the median of ratings for items. Finally, the preferences of the active user are predicted based on the weighted matrix. A large database of user ratings for movies from the MovieLens recommender system is used, and the performance is evaluated. The proposed method is shown to outperform earlier methods significantly.