• 제목/요약/키워드: Car Sound

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A study on the estimation of acoustic performance of exhaust system with 3 dimensional visco-convective wave equation and dopplerized algorithm (3차원 대류 파동 방정식과 도플러 알고리즘을 이용한 배기계의 소음 성능 예측에 관한 연구)

  • Jang, Jin-Man;Kim, June-Wan;Kim, Joong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.821-832
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    • 2011
  • Recently, the noise of vehicle is the one of the key factors for customers to purchase a vehicle and the most important part which is related to the noise is the exhaust system. Thus, car makers have their own ways to assess this exhaust noise not only to decrease the level of noise but to enhance the feeling of it. Typically, to do these things in the early stage of development, the tuning code of the exhaust system has to be made by CAE tool, which is very reliable but expensive, and the prototype parts of this code would be made for the validation test. Then this process can be iterated to meet the target of the performance. In this study, a new algorithm which adapts the '3 dimensional convective sound wave theory 'and 'Doppler effect' has been developed. With this new algorithm, a brand new system for the calculation of tail pipe noise has been developed and validated by acoustic wind tunnel test. As a result of this study, various comparisons and have been carried out, for example, the comparison with other CAE tool has been performed for the validity and the improvement of the new calculation code could be achieved.

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THE REMINERALIZING EFFECTS OF EARLY ENAMEL CAR10US LESION BY SUPERSATURATED BUFFER SOLUTION UNDER PH CYCLING MODEL (pH 순환 모델에서 과포화 용액의 초기 우식 법랑질에 대한 재광화 효과)

  • 김소라;홍석진;노병덕;이찬영;금기연
    • Restorative Dentistry and Endodontics
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    • v.26 no.4
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    • pp.341-349
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    • 2001
  • Dental caries is the most common oral disease. There are many factors contributing to its development, but complete understanding and prevention are not fully known. However, it is possible to remineralize the early enamel curious lesion by fluoride containing remineralization solution. Recently the pH-cycling model has been used to examine the effect of fluoride solution on remineralization of artificial caries in vitro as it can closely simulate the conditions encountered in vivo within a carefully controlled environment. The aim of this study was to evaluate the remineralizing effects of supersaturated buffer solutions under pH-cycling model. The specimen with 3mm-diameter was made using mature bovine incisors which has no caries and has sound enamel surface. Early curious lesions were produced by suspending each specimens into demineralization solution at pH 5.0 for 33 hours and the specimen whose surface hardness value ranged from 25 to 45 VHN were used. The pH cycling treatment regimen consisted of 5 min soaks of three treatment solutions four times per days for 15 days and the continuous cycling of demineralization and remineralization were carried out for 15 days. Following the pH-cycling treatment regimen, the specimens' surface microhardness were measured by the Vickers hardness test (VHN) and analyzed by ANOVA and Duncan's multiple-range test. 1. The surface microhardness value of supersaturated solution, Senstime, and Gagline groups were increased after pH cycling, and that of supersaturated solution was significantly Increased compared to saline group(P<0.05). 2. The surface remineralization effect of fluoride containing solutions was accelerated by saliva under pH-cycling mode 3. The pH cycling model was considered appropriate to mimic the intra-oral pH changes when evaluating demineralization and remineralization in vitro. Under the results of above study, salivary remineralization effect can be improved by fluoride containing remineralization solution. The pH-cycling model was considered appropriate to mimic the intra-oral pH changes when evaluating demineralization and remineralization in vitro.

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Life Cycle Assessment on the End-of-Life Vehicle Treatment System in Korea (국내 폐자동차 처리시스템에 대한 전과정평가)

  • Hong, Seok-Jin;Jeong, Kee-Mo;Hong, John-Hee;Yun, Ju-Ho;Hur, Tak
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.105-112
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    • 2005
  • This study aims at evaluating the environmental impacts stemmed from the End-of-Life Vehicle(ELV) treatment systems in Korea, using Life Cycle Assessment(LCA) method. In this study, both environmental burden from the ELV dismantling process & recycling processes and environmental benefit which were derived from the avoided environmental impacts by substituting recycled materials for virgin materials were considered. First of all, the key issues which were defined as the environmental aspects that account for more than $1\%$ out of the total environmental impacts were identified from the Life Cycle Impact Assessment(LCIA). $CO_2$, crude oil, natural gas, coal, etc. were found out to be the key issue parameters. From the LCI Analysis and LCIA studies, it was shown that the significant environmental aspects were related with the recycling process of ferro scrap, the shredding process of compressed car bodies and the dismantling process of end-of-life engines. In particular, the recycling process of ferro scrap has the most significant effects on the environmental impacts of the ELV treatment systems. Based on these results, it is recommended to improve the recycling process of ferro scrap in order to make the ELV treatment systems more environmentally sound.

Detecting the screw-assembly state of a valve-body using the AR method (AR 방식을 이용한 밸브바디의 나사 조립 상태 검지)

  • Kang, Moon-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.24-30
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    • 2021
  • In this study, an augmented reality (AR) app that detects the screw-assembly state of a car valve-body and assists the assembly work is developed and the effectiveness of the app is shown through testing. The app creates the contents indicating the screw-assembly position and order, and the screw-assembly state. Then, the contents are registrated onto the valve-body image on a smart-phone screen to be shown to the worker during assembly. To this end, the features are extracted from the 2D image of the valve-body and the location of the valve-body is tracked. By extracting the areas where the screws are to be assembled, and periodically determining the luminance of these areas, it is checked whether the screws are assembled in order at the predetermined position of the valve-body. When an error is detected during assembly, a warning sound is notified to the worker, and the worker can check the assembly state on the smart-phone screen and handle the error, immediately. Study results found that it takes about 65 ms to detect the assembly state of the five screws, and the assembly state is detected without error for 1 hour.

Automotive Safety and Convenience Service Using Bluetooth and Smartwatch (블루투스와 스마트워치를 활용한 자동차 안전 및 편의 서비스)

  • Park, Han-Saem;Im, Noh-Gan;Cho, Ji-Yeon;Lee, Jong-Bae;Lee, Seongsoo
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1188-1191
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    • 2020
  • In this paper, automotive safety and convenience service is proposed based on bluetooth and smart watch. The proposed service performs accident detection, kidnapping detection, kid-left-alone-in-car detection, parking location recording, and smart key function. Conventional smartphone services often fails to precisely recognize accident and kidnapping situations since smartphone is located on the dashboard or in the bag. On the contrary, smartwatch recognizes accident and kidnapping situations more precisely since it is always worn on the wrist with hearbeat monitoring. The proposed service recognise various situations around drives and passengers using acceleration sensor, GPS sensor, heartbeat sensor and bluetooth link status. It also performs accident notice, sound recording, and other necessary actions. It also performs door opening, door closing, hazard light flickering, and other necessary actions using OBD-II connection to the vehicle.

Evaluation of Non-slip for Vehicle's Environmental Sub-Mat (자동차용 친환경적인 Sub-Mat의 Non-Slip기능 평가)

  • Eo, Yu-Rim;Kim, Ki-Tai;Kim, Joo-Yong;Kim, Young-Su
    • Science of Emotion and Sensibility
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    • v.15 no.2
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    • pp.177-182
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    • 2012
  • Automotive sub-mat carpet for convenience and comfort of floor administration is additional supplemented floor mat. Sub Mat Backing of the current vehicle's materials reclaimed rubber, PVC, etc. are used, but secondary rubber and PVC Backing have bad sound absorption. Also rubber is heavy too. Contact surfaces between PET staple fiber, PET non-woven, PVC backing and car's floor carpet was measured the coefficient of friction for each sub-mat's non-slip evaluation. A surface of PET non-woven sub-mat has the highest coefficient of friction. Each of sample was observed by optical microscope the contact surfaces before and after. Contact surfaces of PET staple fiber sub-mat was changed increasingly to non-woven. This fact is shown that the sub-mat would be tangled between its contact surface and top of the floor carpet. It is expected to be highly non-slip. In case of PET non-woven sub-mat had not different for contact surfaces between before and after. And PVC backing was shown lower non-slip than other samples. The result of optical microscope and coefficient of friction is seems to be related.

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A Reading Trainning Program offering Visual-Auditory Cue with Noise Cancellation Function (잡음제거 기능을 갖춘 시-청각 단서 제공 읽기 훈련 프로그램)

  • Bang, D.H.;Kang, H.D.;Kil, S.K.;Lee, S.M.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.2 no.1
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    • pp.35-43
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    • 2009
  • In this paper, we introduce a reading training program offering visual-auditory cue with noise cancellation function (RT program) developed by us. The RT program provides some training sentences with visual-auditory cues. Motor speech disorder patients can use the visual and/or auditory cues for reading training. To provide convenient estimation of training result, we developed a noise cancellation algorithm. The function of the algorithm is to remove noise and auditory-cues which are recorded with reading speech at the same time while patient read the sentences in PC monitor. In addition, we developed a function for finding out the first starting time of reading sound after a patient sees a sentence and begins to read the sentence. The recorded speeches are acquired from six people(three male, three female) in four noisy environments (interior noise, white noise, car interior noise, babble noise). We evaluated the timing error for starting time between original recorded speech and processed speech in condition of executing noise cancellation function and not executing. The timing error was improved as much as $4.847{\pm}2.4235[ms]$ as the effect of noise cancellation. It is expected that the developed RT program helps motor speech disorder patient in reading training and symptom evaluation.

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Study of Quantitative Assessment Standard for Type 1 and Type 2 Gas Cylinders Using Acoustic Emission Testing (음향방출법을 이용한 Type 1 및 Type 2 가스실린더의 정량적 평가기준에 대한 연구)

  • Kim, Dong-Hyun;Lee, Sang-Bum;Kim, Kyung-Hoon;Yoon, Dong-Jin;Bae, Dong-Myung
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.2
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    • pp.176-183
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    • 2014
  • Acoustic emission testing (AET) of cylinders is advantageous in that it can be directly conducted on cylinders installed in a car, without needing to dissemble them on a real-time basis. Therefore, users prefer AET over other nondestructive testing methods. Owing to these advantages of AET, it has been approved by the Department of Transportation of the U.S. as a safety evaluation method for pressure containers or as an alternative to the hydroproof testing method. This paper presents a study of the quantitative evaluation criteria for a container having ultrasonic testing defects and also for Type 1 and Type 2 gas cylinders, which are defective seamless pressure containers provided by NK, a manufacturer of pressure containers. For the Type 1 cylinder, the process from crack growth to leak was observed in a repetitive fatigue test using a 113 L container according to ASTM E 1419-02. Further, for the Type 2 cylinder, integrity was evaluated using a 119 L sound container and a container damaged by hydraulic pressure, by the slow-fill method according to ASTM E 2191-02. Based on the AET results of the Type 1 and Type 2 cylinders, quantitative evaluation criteria were established for a defective and non-defective container.

IN VITRO COMPARISON OF VARIOUS DIAGNOSTIC METHODS OF OCCLUSAL CAR10US LESIONS (교합면 우식병소의 다양한 진단법에 관한 비교연구)

  • Kim, Jae-Gon;Kim, Young-Jin;Kim, Young-Sin;Baik, Byeong-Ju
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.4
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    • pp.613-619
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    • 2001
  • The aims of this study were to compare the accuracy, sensitivity and specificity of cnventional visual examination, radiography and a new laser fluorescence method, KaVo Diagnodent, for the detection of occlusal caries lesions. One hundred sound human premolars and molars which had no restorations or interproximal cavities were tested by three methods. Tooth lesions depth was assessed at histologic examination using Caries detector dye The following results were obtained. 1. Diagnodent show 7.8 in sound tooth, 25.4 in initial caries, 30.5 in enamel caries, and 53.8 in dentin caries with average score 2. Spearman and Pearson relation coefficient was high between tooth-specimen test with dye and Diagnodent(0.736, 0.619), visual examination(0.664, 0.666), and was low between tooth-specimen test with dye and radiographic examination(P<0.01, total) 3. Accuracy of occlusal caries was highest on Diagnodent(65%) and lowest on radiographic examination(35%) 4. In initial caries, the sensitivity and specificity of Diagnodent method was the highest. In enamel caries, the sensitivity of visual examination was the highest and specificity of Diagnodent method was the highest. In dentinal caries, the sensitivity and specificity of Diagnodent method was the highest and sensitivity of visual examination was the lowest.

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Shopping Value, Shopping Goal and WOM - Focused on Electronic-goods Buyers (쇼핑 가치 추구 성향에 따른 쇼핑 목표와 공유 의도 차이에 관한 연구 - 전자제품 구매고객을 중심으로)

  • Park, Kyoung-Won;Park, Ju-Young
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.2
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    • pp.68-79
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    • 2009
  • The interplay between hedonic and utilitarian attributes has assumed special significance in recent years; it has been proposed that consumption offerings should be viewed as experiences that stimulate both cognitions and feelings rather than as mere products or services. This research builds on previous work on hedonic versus utilitarian benefits, regulatory focus theory, customer satisfaction to address two question: (1) Is the shopping goal at the point of purchase different from the shopping value? and (2) Is the customer loyalty after the use different from the shopping value and shopping goal? We surveyed 345 peoples those who have bought the electronic-goods within 6 months. This research dealt with the shopping value which is consisted of 2 types, hedonic and utilitarian. Those who pursue the hedonic shopping value may prefer the pleasure of purchasing experience to the product itself. They tend to prefer atmosphere, arousal of the shopping experience. Consistent with previous research, we use the term "hedonic" to refer to their aesthetic, experiential and enjoyment-related value. On the contrary, Those who pursue the utilitarian shopping value may prefer the reasonable buying. It may be more functional. Consistent with previous research, we use the term "utilitarian" to refer to the functional, instrumental, and practical value of consumption offerings. Holbrook(1999) notes that consumer value is an experience that results from the consumption of such benefits. In the context of cell phones for example, the phone's battery life and sound volume are utilitarian benefits, whereas aesthetic appeal from its shape and color are hedonic benefits. Likewise, in the case of a car, fuel economics and safety are utilitarian benefits whereas the sunroof and the luxurious interior are hedonic benefits. The shopping goals are consisted of the promotion focus goal and the prevention focus goal, based on the self-regulatory focus theory. The promotion focus is characterized into focusing ideal self because they are oriented to wishes and vision. The promotion focused individuals are tend to be more risk taking. They are more sensitive to hope and achievement. On the contrary, the prevention focused individuals are characterized into focusing the responsibilities because they are oriented to safety. The prevention focused individuals are tend to be more risk avoiding. We wanted to test the relation among the shopping value, shopping goal and customer loyalty. Customers show the positive or negative feelings comparing with the expectation level which customers have at the point of the purchase. If the result were bigger than the expectation, customers may feel positive feeling such as delight or satisfaction and they would want to share their feelings with other people. And they want to buy those products again in the future time. There is converging evidence that the types of goals consumers expect to be fulfilled by the utilitarian dimension of a product are different from those they seek from the hedonic dimension (Chernev 2004). Specifically, whereas consumers expect the fulfillment of product prevention goals on the utilitarian dimension, they expect the fulfillment of promotion goals on the hedonic dimension (Chernev 2004; Chitturi, Raghunathan, and Majahan 2007; Higgins 1997, 2001) According to the regulatory focus theory, prevention goals are those that ought to be met. Fulfillment of prevention goals in the context of product consumption eliminates or significantly reduces the probability of a painful experience, thus making consumers experience emotions that result from fulfillment of prevention goals such as confidence and securities. On the contrary, fulfillment of promotion goals are those that a person aspires to meet, such as "looking cool" or "being sophisticated." Fulfillment of promotion goals in the context of product consumption significantly increases the probability of a pleasurable experience, thus enabling consumers to experience emotions that result from the fulfillment of promotion goals. The proposed conceptual framework captures that the relationships among hedonic versus utilitarian shopping values and promotion versus prevention shopping goals respectively. An analysis of the consequence of the fulfillment and frustration of utilitarian and hedonic value is theoretically worthwhile. It is also substantively relevant because it helps predict post-consumption behavior such as the promotion versus prevention shopping goals orientation. Because our primary goal is to understand how the post consumption feelings influence the variable customer loyalty: word of mouth (Jacoby and Chestnut 1978). This research result is that the utilitarian shopping value gives the positive influence to both of the promotion and prevention goal. However the influence to the prevention goal is stronger. On the contrary, hedonic shopping value gives influence to the promotion focus goal only. Additionally, both of the promotion and prevention goal show the positive relation with customer loyalty. However, the positive relation with promotion goal and customer loyalty is much stronger. The promotion focus goal gives the influence to the customer loyalty. On the contrary, the prevention focus goal relates at the low level of relation with customer loyalty than that of the promotion goal. It could be explained that it is apt to get framed the compliment of people into 'gain-non gain' situation. As the result, for those who have the promotion focus are motivated to deliver their own feeling to other people eagerly. Conversely the prevention focused individual are more sensitive to the 'loss-non loss' situation. The research result is consistent with pre-existent researches. There is a conceptual parallel between necessities-needs-utilitarian benefits and luxuries-wants-hedonic benefits (Chernev 2004; Chitturi, Raghunathan and Majaha 2007; Higginns 1997; Kivetz and Simonson 2002b). In addition, Maslow's hierarchy of needs and the precedence principle contends luxuries-wants-hedonic benefits higher than necessities-needs-utilitarian benefits. Chitturi, Raghunathan and Majaha (2007) show that consumers are focused more on the utilitarian benefits than on the hedonic benefits of a product until their minimum expectation of fulfilling prevention goals are met. Furthermore, a utilitarian benefit is a promise of a certain level of functionality by the manufacturer or the retailer. When the promise is not fulfilled, customers blame the retailer and/or the manufacturer. When negative feelings are attributable to an entity, customers feel angry. However in the case of hedonic benefit, the customer, not the manufacturer, determines at the time of purchase whether the product is stylish and attractive. Under such circumstances, customers are more likely to blame themselves than the manufacturer if their friends do not find the product stylish and attractive. Therefore, not meeting minimum utilitarian expectations of functionality generates a much more intense negative feelings, such as anger than a less intense feeling such as disappointment or dissatisfactions. The additional multi group analysis of this research shows the same result. Those who are unsatisfactory customers who have the prevention focused goal shows higher relation with WOM, comparing with satisfactory customers. The research findings in this article could have significant implication for the personal selling fields to increase the effectiveness and the efficiency of the sales such that they can develop the sales presentation strategy for the customers. For those who are the hedonic customers may be apt to show more interest to the promotion goal. Therefore it may work to strengthen the design, style or new technology of the products to the hedonic customers. On the contrary for the utilitarian customers, it may work to strengthen the price competitiveness. On the basis of the result from our studies, we demonstrated a correspondence among hedonic versus utilitarian and promotion versus prevention goal, WOM. Similarly, we also found evidence of the moderator effects of satisfaction after use, between the prevention goal and WOM. Even though the prevention goal has the low level of relation to WOM, those who are not satisfied show higher relation to WOM. The relation between the prevention goal and WOM is significantly different according to the satisfaction versus unsatisfaction. In addition, improving the promotion emotions of cheerfulness and excitement and the prevention emotion of confidence and security will further improve customer loyalty. A related potential further research could be to examine whether hedonic versus utilitarian, promotion versus prevention goals improve customer loyalty for services as well. Under the budget and time constraints, designers and managers are often compelling to choose among various attributes. If there is no budget or time constraints, perhaps the best solution is to maximize both hedonic and utilitarian dimension of benefits. However, they have to make trad-off process between various attributes. For the designers and managers have to keep in mind that without hedonic benefit satisfaction of the product it may hard to lead the customers to the customer loyalty.

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