Recently, automotive are used not only as a means of transportation, but also as a private and leisure spaces. In order to secure competitiveness in the automobile market, we must improve durability and noise/vibration technologies. The driver wants to keep quiet even if the car is used for a long time. The types of noise and vibration generated by the automotive can be divided into NVH and BSR. NVH should be reduced because it is caused by mechanical defects and aging. In this study, it was possible to accurately analyze the cause of noise and vibration, also it could identify the location, and repair that. In the future, research of an abnormal and vibrations such as NVH and BSR in automotive is needed to clearly identify.

Automotive technology has developed rapidly and is becoming the intensive of cutting edge technology. For this reason, Automotive are used not only as a means of transportation, but also as a private and leisure spaces. The driver wants to keep quiet even if the car is used for a long time. NVH should be reduced because it is caused by mechanical defects and aging. In this study, it was presented that a seven-step procedure for failure diagnosis and repair to reduce noise/vibration. NVH was diagnosed by comparing the result of the rotator order tracking analysis with the problem frequency. It was possible to accurately analyze the cause of noise and vibration, also it coud identify the location, and repair that.

황산은 뛰어난 촉매제로서의 특성과 경제성으로 산업현장에서 다양한 화학 반응에 널리 사용되고 있다. 그러나 황산은 사용 후 재활용이 불가능하고 대량의 폐수를 발생시키는 특성이 있어 폐기과정에서 환경오염의 위험이 있으며 폐수 처리 과정에서 추가적인 비용 과 에너지가 소모된다. 본 연구는 황산을 대신할 수 있는 친환경 촉매제를 활용하여 폐수 의 배출을 줄이고 기업의 친환경 경영을 강화할 수 있는 방안을 모색하고자 실시되었다. 연구에서는 아민 산화반응을 위해 사용되는 말레인산 무수물 기반 고분자 촉매인 PIMA 과 POMA을 평가하여 피리딘 유도체의 아민 산화반응을 최적화하였다. POMA 촉매는 아연 피리치온 합성에 적용되었으며, 98% 이상의 선택성과 93% 이상의 합성 수율로 높은 촉매 활성을 보였다. 또한 촉매는 여과 과정을 통해 쉽게 회수되었으며, 회수율은 99.8% 를 초과하였고, 여러 번 사용 후에도 활성을 유지하였다. POMA 촉매는 전통적인 황산 촉매를 대체하여 폐수 발생에 의한 환경 부담을 최소화하고 기업의 ESG 경쟁력을 높이는 데 기여할 것으로 기대한다.

A Catholic school is a school that spreads religious ideology to students by combining religious education with regular school curriculum. But, most Catholic schools do not have a separate liturgical space, mass is performed in multipurpose spaces such as auditoriums, and are exposed to severe acoustic defects due to the very aging facilities and lack of sound performance suitable for the liturgical space. So, in this study, an improvement plan was proposed using sound simulation after identifying acoustic defects through field measurements in the liturgical space of Haeseong High School in Jeonju. Also, hearing experiment using Acoustic Psychological Analysis was conducted to identify changes in subjective responses felt by students as they improved their acoustic performance. The results of study, before and after sound performance improvement sound pressure level(SPL500Hz) was 64.8dB at 66.7dB, the weighted sound level(SPLdB(A)) was 67.9dB(A) at 75.8dB(A), reverberation time(RT500Hz) was 2.04sec at 2.52sec, definition(D50,500Hz) was 40.2% at 33.5%, clarity(C80.500Hz) was –0.8dB at –1.18dB, and RASTI was 57.7% at 49.2% was evaluated. In addition, the amount of improvement in subjective responses before and after sound performance through psycho-acoustic experiment decreased by “Reverberation” -17.0%, “Loudness” -11.3% and increased by “Clear” 21.3%, “Vivid” 21.3%, “Intimacy” 12.4%, “Warmth” 14.3%, “Stability” 19.3%, “Godliness” 18.8%. Therefore, after improving sound performance, Haesung High School's liturgical space improved satisfaction with subjective sound performance felt by students and teachers to ensure sound performance suitable for the liturgical space.

A Catholic school is a school that spreads religious ideology to students by combining religious education with regular school curriculum. But, most Catholic schools do not have a separate liturgical space, mass is performed in multipurpose spaces such as auditoriums, and are exposed to severe acoustic defects due to the very aging facilities and lack of sound performance suitable for the liturgical space. So, in this study, an improvement plan was proposed using sound simulation after identifying acoustic defects through field measurements in the liturgical space of Haeseong High School in Jeonju. Also, hearing experiment using Acoustic Psychological Analysis was conducted to identify changes in subjective responses felt by students as they improved their acoustic performance. The results of study, before and after sound performance improvement sound pressure level (SPL500Hz) was 64.8dB at 66.7dB, the weighted sound level (SPLdB(A)) was 67.9dB(A) at 75.8dB(A), reverberation time (RT500Hz) was 2.04sec at 2.52sec, definition (D50,500Hz) was 40.2% at 33.5%, clarity (C80.500Hz) was –0.8dB at –1.18dB, and RASTI was 57.7% at 49.2% was evaluated. In addition, the amount of improvement in subjective responses before and after sound performance through psycho-acoustic experiment decreased by “Reverberation” -17.0%, “Loudness” -11.3% and increased by “Clear” 21.3%, “Vivid” 21.3%, “Intimacy” 12.4%, “Warmth” 14.3%, “Stability” 19.3%, “Godliness” 18.8%. Therefore, after improving sound performance, Haesung High School's liturgical space improved satisfaction with subjective sound performance felt by students and teachers to ensure sound performance suitable for the liturgical space.

Building Equipment field is getting important recently which satisfies the requirement for pleasant living environment. But, the noise generated in the machinery room often violates the pleasant living environment of residents in complicated form of airborne noise and soild sound, its seriousness is increasing so that damage of noise can take large percentage of environmental complaints. So, soundproofing and insulation of sound which can minimize such noise and effective countermeasure in case of civil appeal are required, but research materials regarding building equipment are definitely insufficient domestically. In this respect, this study used Zwicker parameter which is applied by psychological and acoustic reactions according to sound quality, analyzed sound quality of 32 kinds of building equipment used in machine room, and analyzed correlation between dB(A) and PSIL which are items of Zwicker parameter and noise valuation based on that. As the results, if valuates altogether loudness and unbiased annoyance which have high correlation with other existing suggested valuating methods, it is considered that it can be utilized as basic data for more reasonable and accurate grasping characteristics of noise from building equipment and for building effective countermeasure in case of civil appeal.

이 연구는 지진하중 작용시 RC 교각의 겹침이음부에서 발생할 수 있는 종방향 철근의 부착파괴를 방지하기 위한 FRP 래핑 보강공법에 관한 실험적 연구이다. FRP 래핑공법은 수작업 또는 장비를 이용해 교각에 유리섬유를 래핑하고 에폭시 수지를 이용해 고정시키는 공법이다. FRP 래핑공법의 내진성능 보강효과를 확인하기 위해, 겹침이음부가 존재하는 6개의 교각 실험체에 대해 준정적실험을 수행하였다. 실험결과 FRP 래핑공법으로 보강한 교각은 변위연성도 및 에너지소산 능력이 증가하 였으며, 무보강 실험체에 비해 연성거동함을 확인하였다. 또한, FRP 래핑 보강량과 보강효과는 선형비례하지 않으므로 최적 설 계를 통해 교각을 보강하는 것이 효과적임을 확인하였다.

This paper investigates the relationship of voltage and current waveform between normal piezo injector and deterioration abnormal piezo injector. The experimental methods using Pico oscilloscope and GDS scan tool are employed to measure current and voltage waveform and fuel pressure of piezo injector. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) In case of normal injector, the fluctuation of duration time of piezo injector was linearly and regularly decreased with increasing engine speed, but the that of deterioration piezo injector was irregularly decreased with increasing engine speed. 2) In main injection, the peak value of the current waveform of abnormal injector was larger than that of normal injector, the duration time of deteriorated abnormal injector was less than that of normal injector at 800rpm and 1500rpm, but the duration time of deteriorated abnormal injector was larger than that of normal injector at 2000rpm and 3000rpm. This irregularity appears to be caused by the deterioration of the injector.

본 연구의 목적은 플랫 벤치 프레스에서 하지를 지면에 지지한 자세와 하지를 벤치에 지지한 자세에서의 동작 수행 시 대흉근 및 척추기립근의 근 활성 분석을 통해 벤치 프레스 응용동작에 뒷받침 할 만 한 근거자료를 찾고, 운동수행에 관한 효율적인 기초자료를 제시하는데 있다. 대상자는 아마추어 보디빌더 4명, 헬스 트레이너 2명으로 선정하였다. 측정을 위해 연구대상들의 대흉근과 척추기립근에 표면전극을 부착하였다. 벤치 프레스에 대한 동작구간을 설정하고 하지를 지면에 지지한 동작과 하지를 벤치에 지지한 동작으로 나눠 피험자별 10RM으로 각각 1세트씩 실시하는 방식으로 진행하였다. 데이터는 SPSS 20.0을 통하여 분석하였으며 다음과 같은 결과를 얻었다. 플랫 벤치 프레스 동작 시 하지의 지지 유형이 대흉근에는 영향을 미치지 않았지만, 척추기립근에서는 차이가 나타났다.

A pultruded fiber reinforced polymer plastic (PFRP) structural is one of the most widely used composite member in construction. In generally, PFRP members is composed of plate elements so that it needs to evaluate stability problems when they are used by construction members. On the other hand, creep effect may be occurred in PFRP members under sustained load. Primary to experiment for PFRP creep, previous works are studied. In the previous work related to buckling of PFRP member, it can be calculated buckling strength of PFRP members when it is known that material property of longitudinal and transverse direction of PFRP members. The researches for creep behavior of PFRP has been conducted and time-dependent degradation elastic moduls can be predicted by the empirical equation. In this study, it will be conducted creep test for PFRP and time-dependent stress-strain relationship will be plotted. It is expected that long-term buckling behavior of PFRP is evaluated by theoretical and numerical method such as finite element method.

This paper investigates the relationship between the waveform area and fuel injection quantity. It is on developing on analysis method of waveform the effect of waveform area on fuel injection quantity of CRDI Diesel engine. The experimental methods using Pico oscilloscope and fuel injection tester are employed to measure current and voltage waveform and fuel injection quantity of solenoid injector. The one normal and two abnormal solenoid injectors are used. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) The area of the voltage and current waveform of the abnormal injector becomes larger than the that of normal injector, and the area of the current and voltage waveform is inversely proportional to the fuel injection quantity. 2) The area of the current waveform can be obtained more accurate results than that of voltage waveform. 3) It is possible to infer the fuel injection quantity by measuring the current waveform and calculating the area.

In the sewer pipes, reinforced concrete pipes and concrete pipes are mostly used. However, it is difficult to ensure the long-term durability of the pipe due to the corrosion of the rebar which is used for the reinforcement of the concrete. Also, reinforced concrete pipes are difficult to secure watertightness due to deterioration and corrosion by hydrogen sulfide. In order to solve such problems, research on using sewer pipes made of plastic materials is being actively conducted. When soil pressure and live load act on the buried flexible pipe, the load acting on the pipe is transferred to the surrounding soil. So, the flexible pipe will support the load with the surrounding soil together. It is difficult to predict these behaviors theoretically and clearly. Therefore, the design equation for the buried flexible pipe is analyzed by adopting theoretically idealized assumptions and it is estimated through experimental studies that it is similar to the actual structural behavior. In this paper, the mechanical properties of the soil and the polyethylene pipe were considered in application of the method proposed in ASTM D 2412 to design the buried polyethylene pipe. Also, structural behavior of the pipe resisting external loads such as soil pressure was investigated to use a polyethylene pipe as the buried pipe and the long-term behavior of the polyethylene pipe was predicted by the compaction rate of surrounding backfill soil through the field test.

The pultruded fiber reinforced polymer plastic (PFRP) is one of the most actively studied composite materials for the structural member in construction industries. In domestic design process, the PFRP member is designed as an isotropic material having only longitudinal material properties for simplicity, because it is too complex to consider orthotrophy of PFRP perfectly. In this study, three cases of buckling analysis of PFRP plate is conducted theoretically and numerically. First, the PFRP plate is considered as an orthotropic material. Second, the PFRP plate is considered as an isotropic plate having only longitudinal material properties. Third, the PFRP plate is considered as an isotropic plate having geometric mean of longitudinal and transverse material properties. As a result of buckling analysis, a buckling strength of PFRP plate as an isotropic plate having only longitudinal material properties is about 2.21 times larger than that of PFRP plate analyzed as an orthotropic plate. On the other hand, a buckling strength of PFRP plate as an isotropic plate having geometric mean material properties is about 1.19 times larger than that of PFRP plate analyzed as an orthotropic plate. In conclusion, the safety factor of 3 used in domestic design process of PFRP member is no longer applicable due to overestimation of buckling strength of PFRP member which leads to nonconservative design.

This paper is on developing the waveform analysis method in driving control of solenoid injector of CRDI diesel engine. The experimental methods using Pico oscilloscope and scan tool is employed to measure current and voltage waveform of solenoid injector. The solenoid injector are used 1 normal and 2 abnormal injectors. The experiment is carried out during no-load condition. The magnitude of pressure drop is largest main duration, pre and pilot duration in the order named in case of normal injector, whereas was largest pilot duration, pre and main duration in the order named in case of abnormal injectors.

The test was done on cars travelling at the speeds of 20km/h, 60km/h and 100km/h using the performance testing mode for chassis dynamometer. In this test, the secondary ignition waveform, exhaust emissions and fuel consumption were measured in case of faulty MAP sensor, faulty oxygen sensor and spark plugs. The following results from the related analysis of secondary waveform, emission and fuel consumption measurements were obtained : 1) The fuel consumption was higher in the order of oxygen sensor trouble, MAP trouble, spark plug trouble, before maintenance and after maintenance. Maximum fuel economy is 9.3km/L, the minimum fuel economy is 3.2km/L, the difference between max. and min. is 65.5%. 2) If you compare the oxygen sensor trouble with after maintenance, the CO has improved an average of 98%, fuel economy average of 60%. And the HC has improved an average of 87%, fuel economy average of 60%. The fuel consumption and exhaust gas was bad in the order of oxygen sensor trouble, MAP trouble and S/P trouble.