• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.185-191
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• 1999

This paper deals with a method to predict the noise level inside metro electric cars running a single-line tunnel at the speed of 80km per hour using ray tracing method, a kind of ray acoustics generally used for a high-frequency and air-born noise analysis. The interior of the car including a under-frame, seats, side doors, end doors, door-pockets, side panels, end panel, a roof panel and so on is modeled. And in order to describe the noise power coming inside, artificial noise sources are designated using sound transmission loss data of each section measured from simple tests and external noise level. The noise level inside the car is calculated and its properties are investigated. The results satisfy the criteria on noise level inside the car.

• Tribology and Lubricants
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• 제35권3호
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• pp.183-189
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• 2019

The driver seat of an automobile is in direct contact with the driver and provides the driver with a safe and comfortable ride. The seat consists of a frame, a rail, and many recliners. In recent years, strength and operating force measurement testing of the recliner have become vital for designing car seats. However, performance evaluation requires expensive testing equipment, numerous seat products, and considerable time. Therefore, the trend is to reduce experimentation through interpretation. This study examines the lubrication of solid lubricant for automotive seat recliners and confirms the friction and wear performance. In this study, the lubrication behavior of solid lubricants for car seat recliners is investigated to ascertain the friction and wear performance and to provide accurate values for the strength analysis. The friction material consists of a pin and a plate made from steel, which is widely used in recliners. The friction and wear under lubrication conditions are measured by a reciprocating friction wear tester. The friction coefficient is obtained according to the load and speed. Based on the obtained results, it is possible to achieve a reduction in the error of the test value and the analysis by providing the friction coefficient and wear of the lubricant. The results can be applied to the analysis of automobile seat design.

• Industrial Engineering and Management Systems
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• 제10권3호
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• pp.185-190
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• 2011

A driver interacts directly with the car seat at all times. There are ergonomic characteristics that have to be followed to produce comfortable seats. However, most of previous researches focused on either static or dynamic condition only. In addition, research on car seat development is critically lacking although Malaysia herself manufactures its own car. Hence, this paper integrates objective measurements and subjective evaluation to predict seat discomfort. The objective measurements consider both static and dynamic conditions. Steven's psychophysics power law has been used in which after expansion; ${\psi}\;=\;a+b{\varphi}_s^{\alpha}+c{\varphi}_v^{\beta}$ where ${\psi}$ is discomfort sensation, ${\varphi}_s^{\alpha}$ is static modality with exponent ${\alpha}$ and ${\varphi}_v^{\beta}$ is dynamic modality with exponent ${\beta}$. The subjects in this study were local and the cars used were Malaysian made compact car. Static objective measurement was the seat pressure distribution measurement. The experiment was carried out on the driver's seat in a real car with the engine turned off. Meanwhile, the dynamic objective measurement was carried out in a moving car on real roads. During pressure distribution and vibration transmissibility experiments, subjects were requested to evaluate their discomfort levels using vehicle seat discomfort survey questionnaire together with body map diagram. From subjective evaluations, seat pressure and vibration dose values exponent for static modality ${\alpha}$ = 1.51 and exponent for dynamic modality ${\beta}$ = 1.24 were produced. The curves produced from the $E_{q.s}$ showed better $R_{-sq}$ values (99%) when both static and dynamic modalities were considered together as compared to Eq. with single modality only (static or dynamic only R-Sq = 95%). In conclusion, car seat discomfort prediction gives better result when seat development considered both static and dynamic modalities; and using ergonomic approach.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1621-1626
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• 2000

A simplified modeling approach for occupied car seats was demonstrated to be feasible. The model, consisting of interconnected masses, springs and dampers, was initially broken down into subsystems and experiments conducted to determine approximate values for model parameters. A short study of the effect of changing model parameters on natural frequencies, mode shapes and resonance locations in frequency response functions was given, highlighting the influence of particular model parameters on features in the mannequin's vibration response. Good agreement between experimental and simulation frequency response estimates was obtained. Future work should include optimization of parameter estimates, the inclusion of viscoelastic and nonlinear elements in addition to the linear springs and dampers, and finally extensions to a 3D model.

• 한국정밀공학회지
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• 제17권9호
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• pp.109-121
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• 2000

A simplified modeling approach of free vibration for occupied car seats was demonstrated to be feasible. The model consisting of interconnected masses springs and dampers was initially broken down into subsystems and experiments conducted to determine approximate values for model parameters. Which were each stiffness and damping value. Nonlinear equations of motion were derived and model parameters obtained in experiments were applied to these equations. A mathematical model of free vibration for car seat and mannequin system was built with 7 degrees of freedom. in order to calculate natural frequencies and the corresponding mode shapes. linear equations of motion were obtained through linearization. In order to explore the effects of each model parameter free vibration analysis were preformed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.398-403
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• 2001

A simplified modeling approach of forced vibration for occupied car seats was demonstrated by using a mathematical model presented in previous paper. Nonlinear and linear equations of motions were rederived for forced vibration, and the transfer function was used to calculate the frequency response function. The experimental apparatus were set up and hydraulic shaker was used to obtain the system responses. Through the tests, mannequin's head had a lot of problems, and the responses with a head and without a head were measured. To explore the effects of linear dampings and friction moments at the joints, linear analyses were performed. New sets of linear spring and damping coefficients, and torsional dampings at the joints were calculated through parameter study to match up with experimental results. Good agreement between experimental and simulation frequency response estimates were obtained both in terms of locations of resonances and system deflection shapes at resonance, indicating that this is a feasible method of modeling seated occupants.

• 한국ITS학회 논문지
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• 제15권6호
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• pp.127-137
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• 2016

좌석 안전띠는 자동차 안전장치 중 차량의 안전상 가장 중요하고 효과적인 장치로 알려져 왔다. 우리나라의 경우 운해중 안전띠의 착용률, 특히 뒷좌석의 착용률이 낮다. 최근 조사 자료에 의하면 뒷좌석의 안전띠 착용률은 20%의 수준이다. 최근 좌석 안전띠 미착용 알림장치(Seat Belt Reminder, SBR)를 의무화하는 것을 고려중에 있다. 본 연구는 SBR의 의무화할 경우의 도입효과에 대한 분석이다. 본 연구에서 안전띠 착용효과는 해외의 연구사례(Evans(1991) 모형)를 준용하였다. 주요 변수로 안전띠 초기착용률은 국내 조사자료, SBR로 인한 목표 착용률은 운전자 순응도에 따른 시나리오에 따라 추정하였다. 연구 결과, 좌석안전띠 미착용 경고장치의 운전자 순응비율이 90%이상일 경우 매해 119명의 사망자의 감소효과를 가져올 것이고, 편익비용비가 1.84에 달할 것으로 분석되었다.

• 분석과학
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• 제29권3호
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• pp.136-141
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• 2016

충남지역에서 운행되는 10대의 순찰차량에서 유리조각의 분포를 연구하였다. 각 차량의 앞좌석(운전석, 조수석)과 뒷좌석에서 유리조각을 채취하였다. 채취영역은 각 좌석에서 등이 접촉하는 부분(이하 등받이로 표기), 엉덩이가 접촉하는 부분(이하 아랫면으로 표기) 및 엉덩이와 등받이의 사이 공간(이하 모서리로 표기)으로 설정하여 채취하였다. 채취영역에서 접착테이프를 사용하여 전사한 뒤 입체현미경을 사용하여 접착테이프에 있는 유리조각을 찾았다. 발견된 유리조각의 총 개수는 679 개였다. 그 중에서 경찰들이 주로 사용하는 앞좌석에서 발견된 유리조각의 수는 471 개(운전석 293, 조수석 178)였다. 유리조각 대부분의 크기는 0.49 mm 이하였다. 이러한 결과는 유리조각의 대부분이 뒷좌석보다 앞좌석에서 주로 발견된다는 것을 보여준다. 이를 통해 앞좌석에 있던 유리조각이 차량을 사용하는 경찰에게 전이되고, 경찰관이 범죄자와 접촉할 경우 이 유리조각이 범죄자에게 2차전이 될 가능성이 높다는 것을 확인할 수 있었다. 따라서 2차전이로 인해 유리조각 증거가 오염되어 증거가치가 훼손될 수 있다. 그러므로 경찰은 순찰차량에서 발생할 수 있는 교차오염에 대한 방지대책을 강구해야 한다.

• 대한간호학회지
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• 제25권2호
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• pp.362-371
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• 1995

There is no national system to manage, evaluate, and analyse the information about accidents, even though it is necessary for accident prevention policies and health promotion of the general public. The existing studies are, also limited as they focus only on particular group(for example : inpatients, emergency room patients) or on particular geographic areas. Thus the results of the studies cannot be ap-plied to the general public. In order to overcome these limitations, this research focuses on data collection and analysis from accident information for the general population. By providing the analysis on types and causes af accidents, this research aims to produce the basic data necessary for accident prevention policy development. The specific aims of this research are to : 1. Analyse the actual occurrences and characteristics of accidents. 2. Suggest for the accident prevention policies and safety education. Accident report form three major newspaper printed in Korea between January 1, 1989 and December 31, 1993 were collected, and the cause, place, time, and personal injury related to the accidents were classified and then analyzed by de-scriptive statistics. The results of this research conclude : 1. The number of accidents reported by the three newspapers were 2155. 2. The highest proportion of accidents were as follows ; occurred during the June-August(31.2%), Sunday(24.8%), and 5 p.m. (7.6%) of the day. 3. The highest proportion of the accident occurred in Seoul(33. l％), Kyunggi province(14.5%), Kangwon province (7.8％), and Kyungnam prov-ince(6.7%) were next highest. 4. The main causes include car accidents(32.4%), drowning(10.9%), falls(8.8%), explosion(7.1%), and poisoning(5.8%). 5. Slightly more than half of injuries(50.5%) and about two fifths of deaths(40.3%) were caused by car accidents. Therefore, the most serious type of accidents were car accidents. 6. The number of males in accidents were almost three times higher than that of females(males 72.3%, females : 27.7%). 7. The age group from 10 to 19 years old represents the highest proportion(21%) of accidents. 8. The number of the accidents in Korea, based on the information collected from the newspapers, is estimated to be 14, 367 per year. The number of in-juries is estimated to be 88, 480 persons, and the number of deaths 29, 007 respectively. It is said that ninety percent of accidents can be prevented. Several accidents prevention policies are suggested here. 1. Safety education should be done more actively throughtout life, with special emphasis on safety education for children. 2. Safety measures for children(halmets for cycling, children car seats, seats belts, and so on) should be emphasized. 3. An injury surveillance system should be initiated. The initiation of injury reporting system in each factory and school could contribute considerably to the reduction of accidents.

• 한국의류산업학회지
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• 제24권4호
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• pp.372-385
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• 2022

In this study, the patterns expressed on nineteenth-century blue and white porcelain among Joseon white porcelain were selected as the material for the development of the car seat fabric design. It was intended to be applied to car seat design by incorporating Korea's own traditional patterns to fit modern sensibility. First, seven pieces of nineteenth-century blue and white porcelain were selected through the literature, and motifs were produced using adobe illustrator, a computer graphic program. Seven car seat fabric designs were developed according to the construction method and development method of the produced motif. Work 1 was designed to elicit a soft and feminine atmosphere using the peony pattern shown in Table 1-1. Work 2 aimed to express a luxurious atmosphere using the image of the mountain expressed in Table 1-2 as a design material. Works 3 was designed by freely arranging the letters of luck expressed in Table 1-3 to form a free and dynamic image. Work 4 was intended to express a stable and rhythmic atmosphere by horizontally arranging the images of the gently curved wings, tail, and rhythmical tail feathers of the phoenix expressed in Table 1-4. Work 5 was designed in a vertical arrangement using the patterns and silhouettes of the tiger's back expressed in Table 1-5. Work 6 was designed using the wave pattern expressed in Table 1-6 to replicate the rhythmic atmosphere. Work 7 was designed using the images of rocks, waves, and the sun in Table 1-7 to express a calm and antique atmosphere.