• International Journal of Railway
• /
• 제2권3호
• /
• pp.118-123
• /
• 2009

Railway track alignment Standards set a minimum lenght value for straight and circular alignments (art. 5.2.9.), in order to ensure passenger ride comfort in railway vehicles of which dynamic oscillations will thus have to be limited. The transitions between alignments can cause abrupt changes (usually called discontinuities or singular points of the alignment) of curvature, of rate of change of curvature or of rate of change of cant. A passenger is likely to experience effects due to the excitation of the elastic suspension of the vehicle which generates oscillations that are damped as the vehicle moves away from the singularity. The amplitude of these oscillations should be adequately attenuated by the damping of the suspension system within the interval between two successive singular points, especially to avoid resonances. Therefore minimum lengths between two successive singular points are stated in alignment standards. Nevertheless, these nonnative values can be overly conservative in some cases. As an alternative, track alignment designers could try to assess how much the excitation has been attenuated between two successive singular points and thus assess at which point a new singularity may be present without affecting ride comfort. Although such assessment can be made with commercial SW packages which simulate the dynamic behavior of a vehicle considered as a set of rigid bodies interconnected with elastic elements simulating the suspension systems (such as SIMPACK, ADAMS or VAMPIRE), a simplified and user-friendly computation method (based upon the analytical solution of differential equations governing the phenomenon) is made available in this paper to track design engineers, not always used to working with full dynamic models.

• 한국융합학회논문지
• /
• 제10권2호
• /
• pp.227-233
• /
• 2019

주얼리 기업의 경영에 있어 4차 산업과 디자인권의 인식을 알아보고 이를 우리나라 주얼리 산업에 접목함으로서 시대 흐름에 맞는 활용 방안을 제안하기 위해 현재 우리나라 주얼리 산업 현황과 디자인권 실태에 대해 조사하였다. 이론적 배경을 바탕으로 가설을 설정하고 설정된 가설을 중심으로 주얼리 산업 종사자들을 대상으로 4차산업과 디자인권, 경영 마인드, 경영의도에 대해 설문 후 분석하였다. 분석 결과 현재 주얼리 산업에 종사중인 직업과 향후 희망 직업 모두 디자인이 가장 높은 비율로 나타나 우리나라 주얼리 산업은 디자인에 대한 중요도가 높은 것으로 조사되었다. 또한 경영 마인드와 주얼리 산업 경영의 중요요소, 경영 성공 전략으로 모두 디자인이 1순위인 반면, 기술은 마케팅, 자본, 인맥의 요인들 보다 다소 낮은 비중을 차지함을 알 수 있었다. 따라서 시대흐름에 맞는 주얼리 산업의 발전을 도모하기 위해 4차 산업 기술의 적극적인 도입과 디자인권을 함께 운용할 수 있는 융합적 경영 사고가 필요하다.

• 융합정보논문지
• /
• 제8권6호
• /
• pp.187-192
• /
• 2018

본 논문은 풍량 및 운전시간을 제어할 수 있는 방폭 타입 배풍기의 인버터 단자함 연구에 관한 것이다. 국내에서는 열악한 환경에서 작업 시에 풍량 및 운전 시간을 조정할 수 있는 배풍기가 없는 실정이다. 유해가스 및 폭발 위험성이 있는 환경에 적정한 방폭 배풍기의 운전 시간과 풍량을 제어할 수 있는 방폭 단자함을 제작하는 것이 목적이다. 2개의 방폭형 스위치를 사용하여 운전시간을 1 시간, 3 시간, 그리고 연속 시간으로 운전할 수 있도록 하였고, 유도전동기 회전 속도는 2000rpm, 2600rpm, 그리고 3000rpm으로 3 단계로 설정하여 풍량 제어하였다. 실험한 모터는 1/2 마력 3상 유도전동기 사용하였으며 풀 브리지 인버터를 제작하여 원하는 풍량과 운전시간 설정할 수 있도록 연구하였다.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2016년도 추계학술대회
• /
• pp.891-892
• /
• 2016

최근 스마트 홈은 기기 간 관계를 맺어 작업을 동작시키는 연구가 진행되고 있다. 그러나 기존 시스템은 기기가 동작하고 있을 경우 타 기기의 작업이 실행되면 간섭이 발생하여 작업의 효율이 저하될 수 있는 문제점이 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 사용자 기기 선택에 따른 우선순위 자동 설정 알고리즘을 설계하였다. 사용자는 어플리케이션을 통하여 사용할 기기를 선택하고 기기 간 선택 여부를 비교하여 작업 안에서의 우선순위를 설정한다. 이를 통해 사용자가 원하는 기기만으로 작업 환경을 구성할 수 있으며 작업 진행 중 선택되지 않은 타 기기의 간섭이 줄어들기 때문에 효율적인 작업능률을 기대할 수 있을 것으로 사료된다.

• 대기
• /
• 제32권3호
• /
• pp.235-246
• /
• 2022

A large number of MJO skill metrics and process-oriented MJO simulation metrics have been developed by previous studies including the MJO Working Group and Task Force. To assess models' successes and shortcomings in the MJO simulation, a standardized set of diagnostics with the additional set of dynamics-oriented diagnostics are applied. The Global Coupled (GC) model developed for the operation of the climate prediction system is used with the comparison between the GC2 and GC3.1. Two GC models successfully capture three-dimensional dynamic and thermodynamic structure as well as coherent eastward propagation from the reference regions of the Indian Ocean and the western Pacific. The low-level moisture convergence (LLMC) ahead of the MJO deep convection, the low-level westerly and easterly associated with the coupled Rossby-Kelvin wave and the upper-level divergence are simulated successfully. The GC3.1 model simulates a better three-dimensional structure of MJO and thus reproduces more realistic eastward propagation. In GC2, the MJO convection following the LLMC near and east of the Maritime Continent is much weaker than observation and has an asymmetric distribution of both low and upper-level circulation anomalies. The common shortcomings of GC2 and GC3.1 are revealed in the shorter MJO periods and relatively weak LLMC as well as convective activity over the western Indian Ocean.

• 한국의상디자인학회지
• /
• 제24권3호
• /
• pp.1-15
• /
• 2022

The purpose of this study is to compare and analyze the perception of men's fashion before and after the COVID-19 pandemic. TEXTOM allowed the collection of Big Data based on the term 'men's fashion'. As for the data collection periods, Jan. 1, 2018 to Dec. 31, 2019 was set as the pre-COVID-19 era, while Jan. 1, 2020 to Dec. 31, 2021 was set as the post-COVID-19 era. The top 50 words in terms of appearance frequency were extracted from the data. The extracted words were processed using network centrality analysis and CONCOR analysis using Ucinet 6. Research findings were as follows. 1) In the pre-COVID-19 era, the appearance frequency of 'men' was the highest, followed by 'fashion', 'men's fashion', 'brand', 'daily look', 'suit', and 'department store'. These words came up with a high TF-IDF values. Network centrality analysis discovered that 'men', 'fashion', 'men's fashion', 'brand', and 'suit' had a high level of connectivity with other words. CONCOR analysis showed four significant groups: 'fashion item and styles', 'fashion show', 'purchase', and 'collection'. 2) In the post-COVID-19 era, the appearance frequency of 'men' was the highest, followed by 'fashion', 'brand', 'men's fashion', 'discount', 'women', and 'luxury'. These words also displayed high TF-IDF values. Network centrality analysis found that 'fashion', 'men', 'brand', 'men's fashion', and 'discount' had a high level of connectivity with other words. CONCOR analysis showed four significant groups: 'fashion item and style', 'fashion show', 'purchase', and 'situation'. 3) Before the outbreak of the pandemic, men were interested in suits to wear to the office, daily look, and fashion shows in Milan and Paris. They often purchased menswear in multi-brand and open stores. However, they were more interested in sneakers, casual styles, and online fashion shows as social distancing and working from home became common. Most purchased menswear through online platforms.

• 센서학회지
• /
• 제31권6호
• /
• pp.411-417
• /
• 2022

In this paper, we propose a sensor with a C-shaped load cell to detect force change when a person sitting on the chair in an electrical transport-convenience vehicle is pushing ground by both heels. The load cell built in the vehicle is mechanically deformed by the vertical force owing to the human weight and the horizontal force by ground-pushing feet. The deformation rate of the load cell and its distribution are simulated using finite element analysis. In the simulation, the applied loads are preset in the range of 10 kg - 100 kg with a step size of 10 kg, and the ground-pushing force by feet is increased to 40 N with a step size of 5 N with respect to each applied load level. The resistance change of the load cell was observed to be linear in simulation as well as in measurement. the maximum difference between simulation and measurement was 0.89 % when the strain gauge constant was 2.243. The constant has a large influence on the difference. The proposed sensor was fabricated by connecting an instrument amplifier and a microcontroller to a load cell and used to detect the force by ground-pushing feet. To detect foot driving, the reference signal was set to 130% of the load, and the duration of the sensor output signal exceeding the reference signal was set to 0.6 s. In a test of a vehicle built with the proposed sensor, the footpushing force by the worker could be successfully detected even when the worker was working.

• 국제학술발표논문집
• /
• The 8th International Conference on Construction Engineering and Project Management
• /
• pp.343-352
• /
• 2020

Modular integrated construction (MiC) is an innovative construction method where components of a building are manufactured in an offsite factory, trucked to the job site in sections, set in place with cranes, and assembled together to form a whole building. Where circumstances merit, favorable conditions exist and implemented effectively; MiC improves project performance. However, several key factors need to converge during implementation to realize the full benefits of MiC. Thus, a thorough understanding of the factors which are critical to the success of MiC projects is imperative. Drawing on a systematic review of 47 empirical studies, this research identified 25 key success factors (KSFs) for MiC projects. Of these, the five topmost cited KSFs for MiC projects include effective working collaboration and communication among project participants; standardization, optimization, automation and benchmarking of best practices; effective supply chain management; early design freeze and completion; and efficient procurement method and contracting. The study further proposed a conceptual model of the KSFs, highlighting the interdependences of people, processes, and technology-related KSFs for the effective accomplishment of MiC projects. The set of KSFs is practically relevant as they constitute a checklist of items for management to address and deal with during the planning and execution of MiC projects. They also provide a useful basis for future empirical studies tailored towards measuring the performance and success of MiC projects. MiC project participants and stakeholders will find this research useful in reducing failure risks and achieving more desired performance outcomes. One potential impact of the study is that it may inform, guide, and improve the successful implementation of MiC projects in the construction industry. However, the rigor of the analysis and relative importance ranking of the KSFs were limited due to the absence of data.

• 한국축산시설환경학회지
• /
• 제8권3호
• /
• pp.199-208
• /
• 2002

본 연구에서는 실험을 통해 PLC와 하부장치들 사이에 RS -485 직렬 통신방식의 네트웍을 이용한 정보 교환에 있어 잡음 손실이나 왜곡현상이 매우 낮다는 것을 보였다. 제시한 네트웍 방법과 알고리즘에 의해 동작하는 PLC의 효율과 작업 능력을 기반으로 작업장을 분화하여 필요한 작업을 배치한 방법은 매우 효과적이고 편리하며 유용한 정보를 제공하였다. 보다 정확한 정보의 축척과 높은 효율을 위해 본 실험에서 제시한 알고리즘과 운용방법을 각 목장에 활용할 때에는 사용자나 관리자의 요구에 따라 데이터를 통한 계측장비의 교정과 함께 수정이 필요하겠다. 하지만 무엇보다 PLC를 이용한 축산자동화를 통해 사양관리에 필요한 생체 계측 정보를 착유와 동시에 자동으로 다량 획득하여 데이터 전자 문서파일로 보관함으로서, 긴 시간의 지연 없이 사양관리 감독자에게 제공할 수 있는 방법적 해결에 유용성과 신속성을 보였고 사용자나 관리자가 필요한 작업을 수행할 때에 매일 반복적인 작업에 대한 보조적 역할을 하거나 착유 시설과 급이 시설에 완전한 자동화 무인화를 위한 보조적 장비로서 필요한 시설과 정보를 제공하는 것이 가능함을 확인하였다.

• Safety and Health at Work
• /
• 제10권4호
• /
• pp.482-503
• /
• 2019

Introduction: A new third version of the Copenhagen Psychosocial Questionnaire (COPSOQ III) has been developed in response to trends in working life, theoretical concepts, and international experience. A key component of the COPSOQ III is a defined set of mandatory core items to be included in national short, middle, and long versions of the questionnaire. The aim of the present article is to present and test the reliability of the new international middle version of the COPSOQ III. Methods: The questionnaire was tested among 23,361 employees during 2016-2017 in Canada, Spain, France, Germany, Sweden, and Turkey. A total of 26 dimensions (measured through scales or single items) of the middle version and two from the long version were tested. Psychometric properties of the dimensions were assessed regarding reliability (Cronbach α), ceiling and floor effects (fractions with extreme answers), and distinctiveness (correlations with other dimensions). Results: Most international middle dimensions had satisfactory reliability in most countries, though some ceiling and floor effects were present. Dimensions with missing values were rare. Most dimensions had low to medium intercorrelations. Conclusions: The COPSOQ III offers reliable and distinct measures of a wide range of psychosocial dimensions of modern working life in different countries; although a few measures could be improved. Future testing should focus on validation of the COPSOQ items and dimensions using both qualitative and quantitative approaches. Such investigations would enhance the basis for recommendations using the COPSOQ III.