• Title/Summary/Keyword: Technology standard model

Search Result 1,649, Processing Time 0.031 seconds

Comfort Analysis of Mono-ski with Hydraulic Absorber (모노스키 유압 완충장치 특성에 따른 탑승 안락감 평가)

  • Cho, Hyeon-Seok;Park, Jin-Kook;Kim, Gyoo-Seok;Mun, Mu-Sung;Kim, Chang-Boo
    • Transactions of the KSME C: Technology and Education
    • /
    • v.3 no.2
    • /
    • pp.131-140
    • /
    • 2015
  • The mono-ski for the paraplegia designed to skiing is formed as seat bucket on the sled. The impact force transferred by snow surface during skiing is absorbed by the leg joints of normal human, but it is transferred to the human body on the seat when using mono-ski. Most of commercially available mono-ski have absorbing device and link mechanism between seat and ski mount in order to complement it. In this study we developed the comfort evaluation model that could provide skiing simulation of mono-ski with hydraulic damper and analyzed vibrational acceleration occurred during skiing uneven surface. The evaluation method used in this study is the international standard BS6841. We evaluated comfort performance of mono-ski in accordance with nozzle adjustment of hydraulic damper.

A Study on the Development of Service Quality Scale in Traditional Market for Big Data Analysis

  • HWANG, Moon-Young
    • Korean Journal of Artificial Intelligence
    • /
    • v.7 no.1
    • /
    • pp.23-59
    • /
    • 2019
  • The purpose of this study is to develop a measure of service quality in the traditional market by examining previous research on the service quality of the traditional market studied so far. After defining basic concepts through definition of traditional market and existing studies, 5 categories of configuration items for SERVQUAL measurement in traditional market were made up based on existing researches related to definition of service quality and service quality of traditional market. A survey was conducted on the items that fit the intention of this study and various statistical analyzes were conducted. Statistical analysis was performed using SPSS 22.0 and AMOS 22.0. The reliability of the items was measured by the reliability test, and the predictability and accuracy of the items were examined. The validity of the measured variables was verified through confirmatory factor analysis. Reliability, empathy, responsiveness, certainty, and tangibility were the most important factors in this study. Responsiveness factors include communication, time reduction, real time, promptness. Assurance factors include the assurance of delivery, prompt answers, product knowledge items. Tangibility factors include, convenient device systems, location information, presence as a fact, and as a result, the latest modern items are adopted. The quality of service in the traditional market developed in this study was found to be good in reliability and validity test. Confirmatory factor analysis result using structural equation model also met the conformity index standard. If service satisfaction is measured based on this research, basic data can be presented to policy makers who implement policies on traditional markets to make the right decisions. In addition, it will be able to provide traditional market operators with operational strategy and marketing data. In the future, based on the traditional market service quality scale developed in this study, it is necessary to grasp the factors to be continuously managed to improve the service quality of the traditional market, user satisfaction, and intention to use.

A Current Research Insight into Function and Development of Adjuvants (면역보조제의 작용 및 개발)

  • Sohn, Eun-Soo;Son, EunWha;Pyo, SuhkNeung
    • IMMUNE NETWORK
    • /
    • v.4 no.3
    • /
    • pp.131-142
    • /
    • 2004
  • In recent years, adjuvants have received much attention because of the development of purified subunit and synthetic vaccines which are poor immunogens and require adjuvants to evoke the immune response. Therefore, immunologic adjuvants have been developed and testing for most of this century. During the last years much progress has been made on development, isolation and chemical synthesis of alternative adjuvants such as derivatives of muramyl dipeptide, monophosphoryl lipid A, liposomes, QS-21, MF-59 and immunostimulating complexes (ISCOMS). Biodegradable polymer microspheres are being evaluated for targeting antigens on mucosal surfaces and for controlled release of vaccines with an aim to reduce the number of doses required for primary immunization. The most common adjuvants for human use today are aluminum hydroxide and aluminum phosphate. Calcium phosphate and oil emulsions have been also used in human vaccination. The biggest issue with the use of adjuvants for human vaccines is the toxicity and adverse side effects of most of the adjuvant formulations. Other problems with the development of adjuvants include restricted adjuvanticity of certain formulations to a few antigens, use of aluminum adjuvants as reference adjuvant preparations under suboptimal conditions, non-availability of reliable animal models, use of non-standard assays and biological differences between animal models and humans leading to the failure of promising formulations to show adjuvanticity in clinical trials. The availability of hundreds of different adjuvants has prompted a need for identifying rational standards for selection of adjuvant formulations based on safety and sound immunological principles for human vaccines. The aim of the present review is to put the recent findings into a broader perspective to facilitate the application of these adjuvants in general and experimental vaccinology.

Development of a Model of Grading System to improve the Capability of Applying Information of Teachers (교원정보활용능력 향상을 위한 급수제 모델 개발)

  • Kim, Jeong-Rang;Kim, Chul;Park, Sun-Joo;Ma, Dai-Sung
    • Journal of The Korean Association of Information Education
    • /
    • v.3 no.2
    • /
    • pp.120-127
    • /
    • 2000
  • All possible efforts have been done to adapt to the information-oriented society throughout the whole area of education. Especially, it is strongly demanded that teachers should effectively apply information communication and disposal to all the educational activities of instruction-learning, students management, school affairs, and administrative affairs. In this thesis, we chose as educational contents the information technology which is necessary in an educational site to increase the capability of applying information of teachers and developed remote training materials. In addition, we developed measurement instruments to evaluate the capability of applying information of teachers and gave grades to them. Grading System of the Capability of Applying Information of Teachers will be a standard of the capability of applying information.

  • PDF

Train-Structure Dynamic Interaction Analysis of The Bridge Transition Considering Track Irregularity (궤도틀림을 고려한 교대접속부의 열차상호동적거동해석)

  • Choi, Chan-Yong;Kim, Hun-Ki;Chung, Keun-Young;Yang, Sang-Beom
    • Journal of the Korean Geotechnical Society
    • /
    • v.31 no.9
    • /
    • pp.29-38
    • /
    • 2015
  • In this study, track dynamic interaction characteristics caused by the vehicle running through transitional section such as bridge abutments were studied using the finite element analysis program. The geometric condition of track was generated by trigonometric function and allowable maximum track irregularity is determined by KORAIL track maintenance criteria. The sub-infrastructure under rail fastener system was modelled by 3D solid elements. To reduce computational cost only half track line is numerically considered and the roller boundary condition was applied to each side of model. In this study, the vehicle-track dynamic interaction analysis was carried out for standard Korean transition section of concrete track and the dynamic behaviors were investigated. The dynamic characteristics considered are wheel load variation, vertical acceleration at body, and maximum Mises stress at each part of transitional section.

Impact of surface roughness of gypsum materials on adaptation of zirconia cores

  • Kim, Ki-Baek;Kim, Jae-Hong;Kim, Sa-Hak
    • The Journal of Advanced Prosthodontics
    • /
    • v.7 no.3
    • /
    • pp.199-206
    • /
    • 2015
  • PURPOSE. The present study investigated the influences of various gypsum materials on the precision of fit of CAD/CAM-fabricated prostheses and analyzed their correlation with surface roughness. MATERIALS AND METHODS. The master model of the mandibular right first molar was replicated, and four experimental groups based on two types of Type IV stone (GC Fujirock EP, Die keen) and two types of scannable stone (Aesthetic-Basegold, Everest Rock) were created to include a total of 40 specimens, 10 in each group. The surface roughness of the working models for the respective experimental groups was measured. Once the zirconia cores had been fabricated, the marginal and internal fits were measured with a digital microscope using the silicone replica technique. The mean and standard deviation of the respective points of measurement were computed and analyzed through the one-way ANOVA and Tukey's HSD test. The correlation between surface roughness and the precision of fit of the zirconia core was analyzed using the Pearson correlation analysis (${\alpha}$=.05). RESULTS. The zirconia cores fabricated from the scannable stone working models exhibited a superior precision of fit as compared to those fabricated from the Type IV stone working models. The correlation analysis results showed a clear positive correlation between surface roughness and the precision of fit of zirconia cores in all of the experimental groups (P<.05). CONCLUSION. The results confirmed that the surface roughness of dental working models has a decisive influence on the precision of fit of zirconia cores.

Dynamic Analysis of Gimbal Structure System Including Nonlinear Elastic Rubber Vibration Isolator with Shock Acceleration (비선형 탄성 방진 고무부에 충격 가속도를 받는 짐발 구조 시스템의 동적 해석)

  • Lee, Sang Eun;Lee, Tae Won
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.40 no.4
    • /
    • pp.415-422
    • /
    • 2016
  • When shock acceleration is applied to a mechanical system, it may cause malfunctioning and damage to the system. Hence, to prevent these problems when developing a gimbal structure system for observation reconnaissance, the MIL-STD-810G shock standard must be satisfied as a design specification. Rubber vibration isolators are generally assembled on the base of the system in order to reduce the shock transferred from the aircraft. It is difficult to analyze the transient behavior of the system accurately, because rubber has a nonlinear load-deformation curve. To treat the nonlinear characteristic of the rubber, bilinear approximation was introduced. Using this assumption, transient responses of the system under base shock acceleration were calculated by the finite element method. In addition, experiments with a true prototype were performed using the same conditions as the analytical model. Compared with experimental data, the proposed numerical method is useful for the transient analysis of gimbal structure systems, including rubber vibration isolators with nonlinear stiffness and damping.

Operational Implication of R-WeSET Program through Women Students and Companies' Perception and Assessment on the Basis of NCS Key Competency (이공계 여대생과 기업의 NCS 기반 직업기초능력 중요도 인식 및 평가에 의한 R-WeSET 프로그램 운영의 시사점)

  • Kim, Hyun Ju;Pak, Sung Sine
    • Journal of Engineering Education Research
    • /
    • v.21 no.1
    • /
    • pp.27-36
    • /
    • 2018
  • This study aims to deduce operational implication of R-WeSET program through women students in science & engineering and companies's perception and assessment on the basis of NCS key competency. The significant results are as follows. Firstly, companies and women students in science & engineering share a similar perception on importance of NCS key competencies. The programs should be reviewed and improved for women students who are truly aware of companies' needs. Secondly, the main areas of NCS key competency that are poor in companies' perception are 'positive thinking & drive', 'creativity & challenge spirit', 'communication skills' and 'problem-solving skills'. To enhance these weak skills, activating the actual programs such as "Convergence Design Camp", "Field Adaptability Improvement" and developing the new communication program are required. Lastly, most of women students have attained the satisfying result from "Field Competency Reinforcement Program". Especially, "Industry Field Training" shared the great progresses on all skills of key competency, hence why the progressive model should be developed in the future. This study figures out who's the right person for the 4th Industrial Revolution era, producing a meaningful result in order to change in the higher education system of women students and to grow human resources who will contribute to the community and company.

Reduction of a Numerical Grid Dependency in High-pressure Diesel Injection Simulation Using the Lagrangian-Eulerian CFD Method (Lagrangian-Eulerian 기법을 이용한 고압 디젤 분무 시뮬레이션의 수치해석격자 의존성 저감에 관한 연구)

  • Kim, Sa-Yop;Oh, Yun-Jung;Park, Sung-Wook;Lee, Chang-Sik
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.20 no.1
    • /
    • pp.39-45
    • /
    • 2012
  • In the standard CFD code, Lagrangian-Eulerian method is very popular to simulate the liquid spray penetrating into gaseous phase. Though this method can give a simple solution and low computational cost, it have been reported that the Lagrangian spray models have numerical grid dependency, resulting in serious numerical errors. Many researches have shown the grid dependency arise from two sources. The first is due to unaccurate prediction of the droplet-gas relative velocity, and the second is that the probability of binary droplet collision is dependent on the grid resolution. In order to solve the grid dependency problem, the improved spray models are implemented in the KIVA-3V code in this study. For reducing the errors in predicting the relative velocity, the momentum gain from the gaseous phase to liquid particles were resolved according to the gas-jet theory. In addition, the advanced algorithm of the droplet collision modeling which surmounts the grid dependency problem was applied. Then, in order to validate the improved spray model, the computation is compared to the experimental results. By simultaneously regarding the momentum coupling and the droplet collision modeling, successful reduction of the numerical grid dependency could be accomplished in the simulation of the high-pressure injection diesel spray.

Effect of Water on the Kinetics of Nitric Oxides Reduction by Ammonia over V-based Catalyst (바나듐계 촉매상에서 암모니아를 이용한 질소산화물의 환원반응속도에 수분이 미치는 영향에 관한 연구)

  • Kim, Young-Deuk;Jeong, Soo-Jin;Kim, Woo-Seung
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.20 no.6
    • /
    • pp.73-82
    • /
    • 2012
  • The main and side reactions of the three selective catalytic reduction (SCR) reactions with ammonia over a vanadium-based catalyst have been investigated using synthetic gas mixtures in the temperature range of $170{\sim}590^{\circ}C$. The three SCR reactions are standard SCR with pure NO, fast SCR with an equimolar mixture of NO and $NO_2$, and $NO_2$ SCR with pure $NO_2$. Vanadium based catalyst has no significant activity in NO oxidation to $NO_2$, while it has high activity for $NO_2$ decomposition at high temperatures. The selective catalytic oxidation of ammonia and the formation of nitrous oxide compete with the SCR reactions at the high temperatures. Water strongly inhibits the selective catalytic oxidation of ammonia and the formation of nitrous oxide, thus increasing the selectivity of the SCR reactions. However, the presence of water inhibits the SCR activity, most pronounced at low temperatures. In this study, the experimental results are analyzed by means of a dynamic one-dimensional isothermal heterogeneous plug-flow reactor (PFR) model according to the Eley-Rideal mechanism.