Safe operation of freight vehicles is an important issue for drivers, cargo, and other road users. In particular, the center of gravity of a freight vehicle is directly related to the stability of the vehicle, and this can fluctuate in real time depending on weight changes. Every time a freight vehicle loads or unloads cargo, its center of gravity changes, and these changes greatly affect the risk of vehicle rollover. We researched a continuous center of gravity measurement system for freight vehicles for safe driving.

Most conventional instruments measuring disability rely on total score by simply adding individual item responses, which is dependent on the items chosen to represent the underlying construct (test-dependent) and a test statistic, such as coefficient alpha for the estimate of reliability, varying from sample to sample (sample-dependent). By contrast, item response theory (IRT) method focuses on the psychometric properties of the test items instead of the instrument as a whole. By estimating probability that a respondent will select a particular rating for an item, item difficulty and person ability (or disability) can be placed on same linear continuum. These estimates are invariant regardless of the item used (test-free measurement) and the ability of sample applied (sample-free measurement). These advantages of IRT allow the creation of invariantly calibrated large item banks that precisely discriminate the disability levels of individuals. Computer adaptive testing (CAT) method often requiring a testing algorithm promise a means for administering items in a way that is both efficient and precise. This method permits selectively administering items that are closely matched to the ability level of individuals (measurement precision) and measuring the ability without the loss of precision provided by the full item bank (measurement efficiency). These measurement properties can reasonably be achieved using IRT and CAT method. This article aims to investigate comprehensive overview of the existing disability instrument for back pain and to inform physical therapists of an alternative innovative way overcoming the shortcomings of conventional disability instruments. An understanding of IRT and CAT method will equip physical therapist with skills in interpreting the measurement properties of disability instruments developed using the methods.

제품 사용자의 감성 측정 연구에 있어서 제품을 처음 접하는 순간에 무의식적으로 발생하는 초기 감성의 측정은 매우 중요하다. 일반적으로 사용자의 감성은 사용자의 주관적인 평가를 토대로 하는 심리적 측정방법과 생리신호를 이용하는 생리적 측정방법, 그리고 행위적인 반응을 측정하는 행위적 측정방법이 있다. 하지만 각 측정방법들이 초기 감성 측정에 활용될 경우 여러 가지 한계점들이 발생하게 된다. 따라서 본 연구에서는 사용자가 제품을 실제 접하는 환경에서의 초기 감성을 측정할 수 있는 방법을 제안하였다. 먼저 사용자의 초기 감성을 보다 객관적이고 체계적으로 측정하기 위한 초기 감성 측정 프레임워크를 제시하였고, 이에 부합하는 감성 측정 방법들을 활용하여 사용자의 초기 감성을 보다 정확하게 측정할 수 있는 초기 감성 측정 시스템(IEMS)을 제안하였다. 시선 추적 및 동공 크기 변화를 측정하기 위해 모바일 시선 추적 장비를 활용하였고, 행동 관찰을 위한 관찰 카메라와 음성 녹음을 위한 휴대용 음성 녹음기를 결합하여 생리적, 행위적 감성 반응이 측정 가능한 초기 감성 측정 시스템을 제안하였다. 본 연구를 통해 실제 제품을 접하는 환경에서 사용자의 초기 감성을 보다 정확하고 객관적으로 측정할 수 있을 것으로 판단된다.

본 연구는 국내 7개 회사와 일본과 타이완 기업에서 만들어진 PET POY 사의 습열과 건축수축률을 연구하였다. 이들 사(絲)의 열적수축률들은 hank방법 (KSK 0215)과 Toray FTA-500 장치를 사용하여 측정되었으며 측정된 데이터는 측정방법에 따라 분석되고 토의되어졌다. 준비된 시료는 PET POY 85d/72f와 120d/35f이며 더구나 250d/48f와 155d/50f PET POY가 일본과 국내사 사이의 습열과 건열수축률의 비교를 위해서 역시 준비되어졌다. 그리고 각 시료들의 습열과 건열수축률들은 원사 케이크 내의 사(絲), 50,000m를 1개의 layer로 각각 나누어 각각의 layer 별로 측정되어졌으며 급내와 급간 열수축률이 측정 분석되었으며 국내와 외국 수입사(絲)에 따른 차이를 hank와 Toray 측정방법에 따라 분석하였다.

A valve open/close degree measuring device is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or throttle in a hydraulic actuator. In ship, equipments requires safe and robust because of a rough environment and a specific condition during a voyage. Thus, the open/close degree measuring device must be developed which can be used at an outdoor environment. This study developed the open/close degree measuring device using a volumetric measuring method(25㎖/100㎖). The housing of the open/close degree measuring device was made by a stainless steel with surface painting after an anodizing coating.

Recently. the severe competition in the internet shopping mall has forced firms to increase the customer satisfaction and to enhance service quality. Despite the internet shopping mall's fast and superficial growth and extraordinary potential, study on fa

하천수사용 관리를 적정하게 관리하기 위해서는 객관적인 하천수사용량 자료가 수집되어야 한다. 그러나, 하천수 사용자의 취수여건을 고려하여 유량계 외에 수문조작 등의 간접적인 계측방법을 인정하고 있고, 사용자의 자발적인 보고에 의존함에 따라 자료의 객관화가 어려운 실정이다. 이에 한강홍수통제소에서는 농업용수 사용 비중이 커 하천유량 파악이 어려운 만경강의 고산~봉동 수위관측소 구간에 위치한 어우보 취수로에 V-ADCP를 이용한 계측시설을 설치 및 운영하고 있다. 본 연구에서는 V-ADCP로 측정된 유속을 이용하여 실시간 하천수사용량 산정을 위한 유속분포법의 적 용성을 평가하였다. 이를 위해 Chiu의 2차원 유속분포식의 매개변수 민감도를 분석하고, 실측유량 자료에 기초한 최적 매개변수를 산정하였다. 또한 수위-유량관계법, 지표유속법과 비교 평가하여 유속분포법의 특성을 분석하였다.

In accordance with the 1996 London Protocol, the marine dumping of wastewater generated from food was totally banned from 2013. Therefore, establishing a food wastewater bio-gasification facility for stable and continuous food wastewater treatment is necessary. The biogas produced from the wastewater can be used as fuel for electricity generation or for heating in power plants and can be sold as gas in cities as well as fuel for vehicles after undergoing a refining process. Thus, the South Korean government is trying to expand the bio-gasification facility of wastewater generated from food. In this study, we try to obtain information about the public value of such an expansion. For this purpose, the household willingness to pay (WTP) for the expansion is determined by applying the contingent valuation (CV) approach. A total of 1,000 South Korean households were involved in the CV survey, which had questions with dichotomous choices. The mean yearly public value WTP for expansion is estimated at 2,564 KRW per household. If this WTP is extrapolated from the sample to the nation’s population, the expansion in the national value is worth 50.1 billion KRW per year. These results indicate that the expansion of food wastewater bio-gasification facility is supported by Korean households.

As economic growth and development of the living standard causes increasing production of organic waste, the desire to take advantage of organic waste to produce energy is also increasing. Organic waste-to-energy can contribute to improving energy independence through domestic energy security as well as improving the environment by reducing the need for landfills. This paper attempts to quantitatively analyze the non-market benefits arising from the organic waste-to-energy policy. To this end, we apply a contingent valuation (CV) that is most widely used to measure the nonmarket benefits. As for the willingness to pay (WTP) elicitation method, we employed the one-and-one-half-bounded dichotomous choice (DC) model, which produces higher statistical efficiency than the single-bounded DC model and yields greater consistency than the double-bounded DC model. In the CV survey result of 1000 Korean households, a total of 586 households (58.6%) revealed zero WTP. This implies that the use of the mixture model to deal with zero WTP responses was a suitable approach in our study. The yearly mean WTP was computed as KRW 3598 for the next ten years per household, which is statistically significant at the 1% level. Expanding the value to the national population gives us KRW 67.3 billion per year and this value demonstrates the non-market benefits of the organic waste-to-energy policy. This quantitative information could be utilized as a significant reference in the implementation of the organic waste-to-energy policy.

Conventional strain gauge can measure about 15~20% elongation. However, when the steel are ruptured, the strain at the necking region can be much higher than the measurement capacity of the conventional strain gauge. To measure the maximum strain at the necking region a new measurement technique should be developed. In this study, for this purpose image processing method for measuring 2-D strain distribution of tensile specimen of steel is proposed.