• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.55-55
• /
• 2017

본 연구는 파프리카를 자동 수확하기 위한 시스템 개발의 일환으로 수확작업기의 절단장치를 설계하고자 파프리카 과병의 절단특성을 분석하고자 하였다. 파프리카 과병의 절단특성을 분석하기 위하여 사용한 파프리카는 경기도 평택시에서 재배된 파프리카를 사용하였다. 적색 품종인 Nagano RZ와 황색 품종인 Helsinki, 주황색 품종인 Boogie를 사용하였다. 파프리카 과병의 절단 특성을 분석하기 위하여 상기 세 가지 품종의 파프리카 30개씩 총 90개의 파프리카를 사용하여 과병의 중앙 지점을 절단하였다. 절단 특성을 측정하기 위하여 push-pull gauge인 digitect dtg-20을 사용하였으며, 파프리카의 과병의 절단 특성을 측정하기 위하여 일반 농가에서 사용하는 접도 OLFA CK2의 접도의 칼날을 digitect dtg-20에 장착하여 측정하였다. 파프리카 과병의 절단 특성의 시험 항목은 절단강도를 측정하였다. 파프리카의 과병의 절단 특성 측정은 수확작업기의 파프리카 과병의 절단을 위한 절단장치의 설계를 위하여 진행하였다. 파프리카 과병의 절단 특성은 파프리카의 훼손을 최소화한 수확작업을 위한 중요한 요소이다. 파프리카의 과병의 중앙을 절단하여 절단강도와 절단력을 측정하였다. 그 결과 파프리카 과병의 절단강도는 $4.18{\pm}1.18kgf$로 나타났으며, 최대값은 6.91kgf, 최소값은 2.26kgf로 나타났다. 파프리카 과병은 측정된 절단강도의 최대값인 6.91kgf보다 큰 힘을 이용하여 절단하여야 하므로 그에 맞게 수확작업기의 절단장치의 모터를 선정하고 설계가 이루어져야 한다고 판단한다.

• Korean Security Journal
• /
• no.41
• /
• pp.7-36
• /
• 2014

Recently the Korean government announced that minimum wage policy would be applied even to apartment security staffs by 2015 who had been waived from the policy enforcement for their unique work conditions. This caused apartment management to introduce unmanned security system instead of employing security staffs because of fearing possible hike of management fees. People recklessly tend to believe unmaned system is cheaper than maned system if minimum wage guideline is applied. This study examines the economic feasibility of two different apartment security systems by utilizing cost-benefit analysis: maned and unmaned security systems. The authors estimate the costs and the benefits of each security system for 5 years(2014-2018) with application of social discount rate(5.5%). Thirty six apartment complexes at 8 different areas(meons and dongs) in Asan, Chungcheongnam-do province were surveyed. And to attain the exact costs of unmaned system establishment and operation, the authors interviewed persons working for the unmaned security corporations. The benefit-cost(B/C) ratio for unmanned security system is 1.66% at minimum and 1.30% at maximum. while B/C ratio for manned security system is 1.42% and 1.66% respectively. This results mean that people's belief is not correct, that is, transferring from maned system to unmaned is not always economically efficient. Benefits of maned security system is more diverse than unmaned system. The former provides living conveniences(parking helps and keeping parcels) and social benefits(employing aged worker and giving them opportunities to enjoy happier lives) as well as security benefits like crime prevention. The latter provides security benefits only, but that effect is also doubtable. Taking into account these diverse benefits maned system provides, the B/C ratio of maned system is equitable or higher than unmaned system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.1
• /
• pp.98-104
• /
• 2018

The assessment of the light trespass in terms of light pollution is difficult due to the complexity of light environments. As a result, the light pollution research has examined the influences of light pollution using simulation program such as RELUX. However, there still exists a differences between the real measurement value and the simulation value for the light trespass. In this paper, we analyzed the light trespass using the RELUX simulation program, and compared results with real measurement values. In this study, the regions (Seoul, Incheon, etc.) were investigated regarding the light trespass for outdoor lighting. The survey of vertical illuminance was analyzed measuring point (more than 2 point) out the window that was expected to light trespass for the higher anticipated to illumination. The illuminational predicted values for the RELUX program were compared with maximum one. As a result of this study, the illuminational errors between the measurement values and predicted values for the simulation were examined from -0.97 lx to 0.65 lx except 2.08 lx and -7.70 lx. The light trespass was analyzed the higher by how much the located close to the height, length, width of the outdoor lighting for the window. For measuring predicted values using RELUX, it was not sufficiently considered in the simulation conditions because of environmental factors and investigator error etc. Limitations of this study include the limited number of measurements, and greater field data is required in future studies.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.05a
• /
• pp.185-188
• /
• 2005

형광램프는 일정전력을 소비하는 경우, 전원주파수 1[kHz]부근에서 전류는 최대 값을 램프전압은 최소값을 갖는 현상을 나타낸다. 본 논문에서는 원자레벨의 방전 모델식을 만들어 입자밀도와 전자온도의 변화를 수치해석을 이용하여 계산하고, 이를 이용하여 전원주파수에 따라 형광램프의 전류와 램프전압이 변화하는 현상을 이론적으로 설명하였다.

• The Journal of the Acoustical Society of Korea
• /
• v.27 no.5
• /
• pp.256-261
• /
• 2008

In this paper, we propose a novel approach to improve the performance of minima controlled recursive averaging (MCRA) which is based on the conditional maximum a posteriori criterion. A crucial component of a practical speech enhancement system is the estimation of the noise power spectrum. One state-of-the-art approach is the minima controlled recursive averaging (MCRA) technique. The noise estimate in the MCRA technique is obtained by averaging past spectral power values based on a smoothing parameter that is adjusted by the signal presence probability in frequency subbands. We improve the MCRA using the speech presence probability which is the a posteriori probability conditioned on both the current observation the speech presence or absence of the previous frame. With the performance criteria of the ITU-T P.862 perceptual evaluation of speech quality (PESQ) and subjective evaluation of speech quality, we show that the proposed algorithm yields better results compared to the conventional MCRA-based scheme.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.3
• /
• pp.119-124
• /
• 2011

Interpolation filters are widely used in many communication and multimedia applications. Polynomial interpolation computes the coefficients of the polynomial according to the input information to obtain the interpolated value. Recently, FIR interpolation method using supplementary filters was proposed to improve the performances of polynomial interpolation methods. In this paper, by combining a weighting factor approach with the supplementary filter method, we propose a weighted interpolation method which can be efficiently used to compute the maximum or minimum values of a given curve using only a restricted number of sample values. With application to the interpolation of normal distribution curves used in XRF systems, it is shown that the proposed approach exhibits improved performances compared with conventional interpolation methods.

• Journal of the Society of Naval Architects of Korea
• /
• v.34 no.3
• /
• pp.1-8
• /
• 1997

Internal solitary waves between two-stratified fluid layers are examined. Hamilton's principle is used to derive a governing equation. The wave speed-wave height relation is obtained and this agrees well with the experiment. The wave profiles obtained also agree well with the experimental result. There exist minimum and maximum wave speeds depending on the depth ratio and the density ratio of two layers. The KdV equation overpredicts the wave speed for a given wave height and underpredict the wave height for a given wave speed.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.460-460
• /
• 2011

국내에서는 수자원 정보화 사업에 일환으로 국가수자원종합정보시스템(WAMIS)을 개발하여 수자원에 관련된 많은 기초 자료 정보를 일반에 공개 제공하고 있으나, 주 이용 계층은 수자원관련 종사자 또는 연구자들이 대부분이다. 국가수자원종합정보시스템에서 제공하는 양질의 수자원 정보를 일반 국민들이 보다 쉽게 이해하고, 이용할 수 있도록 국내에서는 이들 기초자료를 바탕으로 다양한 수자원 지표 및 지수를 개발하였다. 이러한 수자원 관련 지표 및 지수를 개발하기 위해서는 서로 다른 단위와 특성을 가진 자료들을 모아 하나의 지표로 정의하는 과정이 필요하며, 하나의 지표로 정의되기 위해서는 반드시 표준화(normalization)과정이 필요하다. 국내에서 가장 보편적으로 사용하고 있는 방법은 Z-score법이며, 이외에도 가장 단순하고 간단한 방법인 Ranking 법, 자료의 극값(최대값, 최소값)을 이용하는 Re-scaling법, 일정 지표를 기준으로 하는 Distance to a reference country법 등이 있다. 표준화 방법은 각기 다른 장 단점을 가지고 있으며, 그 특성에 따라 정의되는 지표값은 다르게 나타날 수 있기에 지수값의 변화를 야기시킬 수 있다. 본 연구에서는 기 개발된 물이용안전성지수를 이용하여 기존 분석과 다양한 표준화 방법을 이용하여 지표를 산정하였을 때 표준화 방법에 따른 변화를 분석해 보고자 한다. 기존 연구에서 사용된 표준화 방법은 Z-score법이며, 다른 표준화 방법을 적용해 봄으로서 기존 산정 결과와의 차이를 비교 분석하였다. 지수를 구성하는 세부지표에 따라 수집되는 기초자료의 단위 및 특성은 다양하기 때문에 적합한 표준화 방법을 찾는 과정은 매우 중요하며, 이는 지표를 보다 정확하게 산정할 수 있도록 한다. 합리적인 표준화 방법을 통해 올바른 지수를 도출할 수 있고 객관적으로 수자원 환경을 평가할 수 있으며, 또한 수자원 계획 및 정책 개발에 있어 중요한 기준으로서 적용 할 수 있을 것으로 기대된다.

• The Journal of the Korea Contents Association
• /
• v.15 no.6
• /
• pp.399-410
• /
• 2015

The primary goal of the study is to examine the possibility of applying the time series model to forecasting demand and supply of social services. In the study, we used survey data based on a nationally represented sample which is secondary processed data. We selected developmental rehabilitation service. The analysis, we made models of a demand and a supply using time series analysis. Utilizing the estimates, we identified each model's pattern. This study provides an empirical evidence to suggest benefits of using the time series model for forecasting the demand and the supply pattern of newly introduced social services. We also provide discussions on policy implications of utilizing demand and supply time series models in the process of developing new social services.

• Journal of KIISE:Software and Applications
• /
• v.33 no.8
• /
• pp.692-702
• /
• 2006

In this study, a weighted fuzzy min-max (WFMM) neural network model for pattern classification is proposed. The model has a modified structure of FMM neural network in which the weight concept is added to represent the frequency factor of feature values in a learning data set. First we present in this paper a new activation function of the network which is defined as a hyperbox membership function. Then we introduce a new learning algorithm for the model that consists of three kinds of processes: hyperbox creation/expansion, hyperbox overlap test, and hyperbox contraction. A weight adaptation rule considering the frequency factors is defined for the learning process. Finally we describe a feature analysis technique using the proposed model. Four kinds of relevance factors among feature values, feature types, hyperboxes and patterns classes are proposed to analyze relative importance of each feature in a given problem. Two types of practical applications, Fisher's Iris data and Cleveland medical data, have been used for the experiments. Through the experimental results, the effectiveness of the proposed method is discussed.