• 대한인간공학회지
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• 제36권4호
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• pp.281-292
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• 2017

Objective: This study aims to identify important physical design variables in designing a necklace type wearable device, and to present design guidelines to maximize comfort that a user feels upon wearing the device. Background: Interests in fitness culture and personal health are on the rise recently. In such a situation, demand for necklace type wearable devices is projected to increase a lot, as the devices enable users to use their hands freely and to enjoy various contents through connection with mobile devices. However, the necklace type wearable device's comfort was assessed to have the lowest comfort in a running situation, where human body moves up and down and left and right more than other devices wearable on other human body parts. Therefore, the usability of a necklace type wearable device was low. In this regard, studies on identification of the variables affecting user comfort upon wearing a necklace type wearable device and on physical design direction maximizing comfort and usability are needed. Method: A pretest and a main test were carried out to draw the direction of necklace type wearable device design. In the pretest, wearing evaluation on the diverse types of devices released in the market was conducted to draw physical design variables of the devices affecting comfort. Furthermore, variables significantly affecting the comfort of a device were selected through an analysis of variance (ANOVA). In the main test, anthropometry was performed, and information on anthropometric items corresponding to the design variables selected in the pretest was acquired. Based on the pretest results and the anthropometric information in the main test, the present study produced design guidelines maximizing the comfort of a necklace type wearable device with regard to major design variables upon dynamic tasks. Results: According to the pretest results, the variables having effects on comfort were the angle of side points, width, and height. Due to interactions between variables, those need to be simultaneously considered upon designing a device. Upon dynamic tasks, the angle of side points and width of a device was designed to be smaller than mean angle of the trapezius muscle and neck width, and thus attachment to human body was high. As height was designed to be larger than mean neck front and rear point width, comfort was higher due to feeling of stability. Conclusion: Because user sensitivity to comfort was high at human body's inflection points, a device needs to be designed for users not to feel high pressure on specific body parts with the device fitting human body shape well. A design considering user's situation is also required in further studies.

• 한국철도학회논문집
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• 제11권5호
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• pp.489-498
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• 2008

일반적으로 허용처짐 기준은 정적 사용성과 구조적안전성에 그 기반을 두고 있으며 진동사용성에 대한 고려는 부족하다. 따라서 진동사용성을 고려할 수 있는 교량의 허용처짐 기준이 필요하다고 판단된다. 본 논문에서는, 한국철도교설계기준의 허용처짐기준을 주파수영역의 진동사용성 기준과 비교하였으며, 프랑스 및 일본의 철도교설계기준의 진동사용성 허용기준 또한 분석하였다. 그 결과, 한국철도교설계기준의 경우 열차의 속도에 따른 기준으로 진동지속시간이 부분적으로 고려되었지만 진동사용성은 만족하지 못하고 있는 것으로 판단되었으며, 국외 철도교설계기준비 분석결과, 진동사용성을 고려한 허용처짐기준을 제시할 수 있을 것으로 판단하였다. 공용중인 철도교량의 진동사용성을 평가하기위하여 다양한 형식의 철도교량의 진동신호를 측정하였다. 그리고, 현장에서 적용하기 편리한 진동사용성 처짐 및 강성한계를 제시하기 위하여 공용중인 교량을 대상으로 차량 교량 상호작용해석을 수행하였다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.93-99
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• 2002

Ride comfort, one of the most important performances of a car, is affected by vibration, noise, dynamic movement, and ergonomic factors. Among these factors, ride comfort vibration is heavily affected by the seat system, tire, suspension, and body structure. In this study, vibration characteristics of seat, tire, suspension, and body structure are analyzed. The vibration transfer function from the road input to the human body is also investigated.

• 구강회복응용과학지
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• 제27권1호
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• pp.117-123
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• 2011

총의치 환자의 치료 시 인상 채득 과정은 의치의 지지, 유지, 그리고 안정을 위해 매우 중요하며, 의치의 성공여부를 좌우한다. 총의치 인상 채득을 위한 여러 가지 재료와 방법들이 이용되어 왔으며, 그 중 조직 양화재 (tissue conditioner)를 이용한 동적 인상법 (dynamic impression method)은 보다 생리적이고 기능적인 방법이다. 본 증례들에서는 무치악 환자에서 조직 양화재인 Coe-comfort$^{(R)}$ (GC America, IL, USA)를 이용한 동적 인상법으로 변형된 연조직의 회복과 하께 가장 생리적인 상태로 인상을 채득하여 의치의 제작 및 첨상을 시행하였으며, 만족스런 결과를 얻었다.

• 한국소음진동공학회논문집
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• 제23권7호
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• pp.631-639
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• 2013

Virtual seat method(VSM) which is an evaluation method combined objective and subjective process is used in this study in order to determine seat comfort index of idle vibration of passenger vehicle. The VSM is implemented by two steps which are for objective index in the first step and for subjective estimation in the second step. In the study, two seats mounted on passenger vehicle was compared in terms of dynamic seat comfort by six subjects employed for the VSM method as well as SEAT value which is a conventional objective method. It is concluded that the dynamic comfort index by the VSM is more reliable than the SEAT value thanks to adding subjective evaluation on top of the objective result.

• Wind and Structures
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• 제14권6호
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• pp.559-582
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• 2011

This paper presents an integrated wind-induced dynamic analysis and computer-based design optimization technique for minimizing the structural cost of general tall buildings subject to static and dynamic serviceability design criteria. Once the wind-induced dynamic response of a tall building structure is accurately determined and the optimal serviceability design problem is explicitly formulated, a rigorously derived Optimality Criteria (OC) method is to be developed to achieve the optimal distribution of element stiffness of the structural system satisfying the wind-induced drift and acceleration design constraints. The effectiveness and practicality of the optimal design technique are illustrated by a full-scale 60-story building with complex 3D mode shapes. Both peak resultant acceleration criteria and frequency dependent modal acceleration criteria are considered and their influences on the optimization results are highlighted. Results have shown that the use of various acceleration criteria has different implications in the habitability evaluations and subsequently different optimal design solutions. The computer based optimization technique provides a powerful tool for the lateral drift and occupant comfort design of tall building structures.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.188-193
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• 2007

Airport railroad have required maximum design speed 120km/h and wind speed 50m/s condition as design item of airport railroad vehicles. To design and manufacture the vehicle satisfying these conditions, it must carry out the dynamic behaviors analysis such as hunting stability, ride comfort derailment ratio, unloading ratio and lateral force to meet the criterion described in Urban Railroad Act. Dynamic behaviors of vehicle have carried out using the multi-body dynamics simulation program(VAMPIRE). This paper presents the evaluation methods and criterion used to verify dynamic performance of airport railroad vehicle, and show the analysis results of vehicle dynamic simulation and the test results for vibration and ride comfort measured on running performance tests. As a results, each analysis results and test results meet the criterion described in Urban Railroad Act.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.308-313
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• 2005

An urban railway vehicle has a characteristics such as that a lot of passenger use it and the major of passenger is standee. The ride comfort of standee is greatly influenced by the lateral dynamic characteristics of vehicle. So the lateral vibration is important factor for the improvement of ride comfort. In this study, vibration test of railway vehicle is carried out under the same condition of field driving to find out the major factor of vibration. By considering the test results under the various driving condition, the vibrational characteristics of vehicle is verified.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.321-328
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• 1998

In this study we have studied running stability, safety and passenger comfort of the Chinese first class passenger car made by our company and CCRW. A fine analysis model of 72 d.o.f. was constructed for simulating dynamic behavior of the car on straight and curved tracks having irregularity configurations. We have calculated the various characteristic values such as critical speed, lateral force, derailment ratio, wheel unloading ratio and passenger comfort index, then evaluated them by comparing with reference values.

• Steel and Composite Structures
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• 제31권5호
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• pp.437-452
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• 2019

In this study, in-situ static and dynamic tests of four pre-stressed concrete (PC) track beams with different span lengths and curvatures in a straddle monorail transit system were reported. In the static load tests, the strain and deflection at critical sections of the PC track beams were measured to determine the load bearing capacity and stiffness. The dynamic responses of strain, deflection, acceleration, and displacement at key positions of the PC track beams were measured under different train speeds and train loads to systematically study the dynamic behaviors of the PC track beams. A three-dimensional finite element model of the track beam-vehicle coupled vibration system was established to help understand the dynamic behavior of the system, and the model was verified using the test results. The research results show that the curvature, span length, train speed, and train loads have significant influence on the dynamic responses of the PC track beams. The dynamic performance of the PC track beams in the curve section is susceptible to dynamic loads. Appropriate train loads can effectively reduce the impact of the train on the PC track beam. The PC track beams allow good riding comfort.