This article presents vibration control performances of a semi-active railway vehicle suspension system using magneto-rheological damper tested on the roller rig. In order to evaluate performances, mathematical model with 15 degrees freedom is first derived represent lateral, yaw and roll motions car body, bogie frame, wheel set, respectively. Based formulated model, design parameters are determined undertake compatible comparison dynamic conventional (existing) passive system. The designed...

This work presents experimental assessment of the improvements to horizontal ride quality a railway vehicle equipped with semi-active magneto-rheological (MR) suspension system. The includes development mathematical model and magnetic circuit analysis MR damper, design manufacture field test on railway. After evaluating field-dependent damping force characteristics, conventional passive dampers operational are replaced evaluate dynamic characteristics that directly indicates vehicle. Various...

In this paper, a magneto-rheological (MR) damper was applied to the secondary suspension reduce vibration of car body. The control performance MR verified by numerical analysis with 1/5 scale railway vehicle model in accordance similarity law. results were then validated tests. particular, objective study understand how affected dynamic characteristics and systematically analyze relationship between depending on various running speeds. To achieve this, experimental for scaled designed model....

Direct-acting solenoid valves are used in the automotive industry due to their simple structure and quick response controlling flow of fluid. We performed an optimization study time order improve dynamic performance a direct-acting valve. For optimal design process, we commercial software PIAnO, which provides various tools for efficient including experiments (DOE), approximation techniques, algorithm. 35 sampling points computational find optimum values variables. In all cases, ANSYS...

Velopharyngeal dysfunction in cleft palate patients following the primary repair may result nasal air emission, hypernasality, articulation disorder and poor intelligibility of speech. Among conservative treatment methods, speech aid prosthesis combined with therapy is widely used method. However because its long time more than a year low predictability, some clinicians prefer surgical intervention. Thus, purpose this report was to increase an attention on effectiveness by introducing case...

Ride quality became a very important factor in the performance of railway vehicles according to expansion high-speed railways and speedup velocity vehicles. In this study, results applying MR (magnetorheological) lateral damper on secondary suspension reduce vibration car body, directly relating ride vehicles, were mentioned. order verify control dampers, 1/5 scaled vehicle model was constructed, numerical simulation experimental tests conducted. The for produced attached between body bogie...

This paper deals with efficient operation method for the electromechanical brake (EMB). A three-phase interior permanent magnet synchronous motor (IPMSM) is applied to EMB operation. current controller, speed and position controller based on proportional-integral (PI) control are used drive IPMSM. Maximum torque per ampere (MTPA) perform control. For MTPA control, angle β calculated from total input current, frame d–q axis reference determined by β. The IPMSM designed analyzed finite element...

Due to global warming, there is an increasing number of wind gusts that affect the stability railway vehicles. A vehicle running on a curved track during gust subjected multiple forces simultaneously, which include centrifugal force and exerted by cant, they significantly vehicle’s dynamic characteristics as well its safety. The increase vibration carbodies risk derailment overturning cars; effect worse irregular tracks. In order review phenomenon in detail, 1/20 scale model was built...

In IT business, the capacity of battery in smartphone was drastically improved to digest various functions such as communication, Internet, e-banking, and entertainment. Although is improved, it still needs be upgraded due customer’s demands. this article, we optimize design linear generator with Halbach array improve efficiency harvesting vibration energy during human walking for capacitance. We propose optimal tubular permanent magnet that uses a array. The approximate model established...

Background: Active lateral suspension (ALS) technologies have been well developed for several decades, but they not widely used in service operation due to relatively high costs implementation and maintenance concerns about fail-safe. Therefore, this paper suggests a more practical approach the active system, designed achieve target performance with easy Methods: The control actuator type are determined from vibration energy that ALS has absorb along weight function ride quality evaluation....

Nasalance is used to evaluate the velopharyngeal incompetence in clinical diagnoses using a nasometer. The aim of this study find nasalance differences between Vietnamese cleft palate children and Korean by measuring five oral vowels.Ten after surgery, three for control group, ten surgery with same age participated experimentation. Instead control, standard value version simplified nasometric assessment procedures (kSNAP) was used.The results are as follows: (1) highest score among normal...

In this paper, prior to the commercialization of a developed active steering bogie, we want analyze performance experimentally according angle level with aim obtaining data derive practical design specifications for system. other words, maximum can be obtained by controlling at 100% target angle, but it is necessary establish control range in consideration system cost increase, size and consumer requirements commercialize. The test using bogie was conducted section steep curve radius...

Background and Objectives This study is to prospectively compare analyze the aerodynamic changes in patients with thyroid cancer before after surgery. Changes vocal function thyroidectomy were examined using related assessments. Materials Methods Twenty one evaluated preoperatively, 5-7 days 6-7 weeks postoperatively assess outcomes thyroidectomy. Glottal input power (GIP), glottal efficiency (GE) maximum phonation time (MPT), determined of surgery, surgery Results According comparison...

The rebar factory production process involves the repetitive bending of rebars. Therefore, fatigue failure machine needs to be considered. In this paper, analysis was performed using commercial software DAFUL, which is based on MFBD (Multi Flexible Body Dynamics). rotating roller, fixing roller and were modeled by finite element method. simulated mechanical stresses rollers are calculated. Structural maximum angle processing diameter . Then, for analysis, S-N curve STD-11 was. life estimated...

Velopharyngeal insufficiency that accompanies speech resonance and articulation disorders can be managed through several intervention methods such as speech-language therapy, prosthetic aids, surgery. However, for patients with severe hypernasality, surgical interventions are highly recommended. Among available techniques, the posterior pharyngeal flap is most common.

The steering performance according to the angle control was tested by using active bogie developed reduce excessive wheels and rail wear noise generated when railway vehicle run in a curved section. As result of test increasing accordance with target 300m radius curvature, is gradually aligned radial position, carried out 100% angle, angles front rear bogies appeared almost same. increased, wheel lateral force derailment coefficient also decreased. Therefore, validity position method applied...

국내에서 적용되고 있는 고속철도 차륜답면형상과 레일에 대하여 레일 경좌에 따른 차륜/레일 접촉 해석을 수행하였다. 경좌가 1/40인 경우 GV40 및 XP55 차륜답면형상의 접촉점 분포는 경좌 1/20에 비하여 레일의 내측 방향으로 이동하여 분포한다. 변화로 인한 파라미터 특성은 거의 유사하게 나타나 의한 영향은 매우 작다. 그러나 S1002 차륜답면형상은 영향이 가장 크게 나타났다. 1/20의 특정 영역에 집중되지만 경우에는 차륜과 전체에 걸쳐 넓게 분포 되어 접촉한다. 1/20인 등가답면구배는 0.009, CCI는 1.200, 응력은 1,015MPa이지만 각 0.068, 0.465, 582MPa로 파라미터의 값이 영향을 받는다. 차륜 마모와 관련된 레일경좌 UIC60레일과의 조합에서 작게 마모 예방관점에선 양호한 조합이라 판단된다.