• Journal of the Korean Institute of Gas
• /
• v.26 no.3
• /
• pp.54-59
• /
• 2022

This paper is a purpose to study and analyze the failure examples for timing belt, camshaft position sensor and ignition coil of LPG automotive engine. The first example, whe the service man install the front case bracket of engine, he excessively tightened up a 12mm bolt for being fixed of brackct. As a results, the bolt was separated from joint part so that it was put in between the crankshaft sprocket. Therefore the belt was broken off because of interference between timing belt and sprocket tooth. The second example, it verified the disharmony phenenomen of engine that the gap of the camshaft position sensor and camshaft senseing point assembled on cylinder head part was small more than iregular value so that the it was generated senseing damage phenomenon by pulse signal misconduct. The third example, it was found the engine disharmony phenomenon that the fire in the ignition coil was leaked by inner damage of Number 2 ignition coil.Therefore, the the manager of a car throughtly have to inspect not in order to arise the failure symptoms.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.5
• /
• pp.37-48
• /
• 2010

In this study, the seepage flow monitoring method by the hydraulic head loss rate was developed for the purpose of application to offshore construction site enclosed by cofferdams in which seepage force varies periodically. The amount of the hydraulic head loss rate newly defined in this graph was in a range between 0 and 1. The zero of the rate means the existence of flow with no seepage resistance. The 1 of the rate means no seepage flow through the ground. The closer to 1 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows is stable. The closer to 0 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows was unstable and the higher the possibilities of existence of empty space or of occurrence of piping on the seepage flow pass in the ground is. The hydraulic head loss graph makes it possible to monitor sensitively the situation of seepage flow state, and the graph helps to understand easily the seepage flow state at the specific section on the whole cofferdam.

• Journal of Sensor Science and Technology
• /
• v.6 no.1
• /
• pp.6-15
• /
• 1997

This paper presents the multi-objective optimal design of thermopile sensor having beam or membrane structure. The thermopile sensor is composed of $Si_{3}N_{4}/SiO_{2}$ dielectric membrane, Al-polysilicon thermocouples and $RuO_{2}$ thin film for black body. The sensing method is based on the Seebeck effect which is originated from the temperature difference of the two positions, black body and silicon rim. The objective functions of the presented design are sensitivity, detectivity and thermal time constant. The modelling of the sensor is proposed including the package. The multi-objective optimization technique is applied to the design of the sensor not only inspecting the modelling equation but also simulating mathematical programming method. Especially, fuzzy optimization technique is adapted to get the optimal solution which enables the designer to reach the more practical solution. The design constraint of the voltage output originated from the change of the environmental temperature is included for practical use.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.49 no.2
• /
• pp.39-46
• /
• 2012

The newly designed sense amplifier in this paper has rail-to-rail input range achieving low power consumption. Reducing static power consumption generated due to DC path to ground is key element for low power consumption in this paper. The proposed sense amplifier performs power-saving operation using negative feedback circuit that controls the current flow with the newly added PMOS input terminal. As a simulation result, the proposed sense amplifier consumed about over 50 % efficiency of the average power consumed by the typical Rail-to-Rail sense amplifier.

• Journal of IKEEE
• /
• v.22 no.1
• /
• pp.21-28
• /
• 2018

In this paper, we have developed the intellectual kegel trainer with the bio-feedback. The one is smart health care system that can treat an evacuation impediment and urination polyuria with the low frequency stimulation module. Then this detects the shrinkage power of the pelvis muscles and correlates an smart phone entertainment application program for the users. In order to recover the function of pelvic muscles, we use the intellectual smart health care trainer with several biofeedback function. Such a trainer makes to strength the weakness pelvic muscles by biofeedback training and get exercise the pelvic muscles in physical suppress. The biofeedback training against the physical suppress can have strengthen the pelvic muscles and can display the operation graph of strengthen movement in monitor. Finally, It can be ensured the safety through EMI and performance test.

• Proceedings of the Korea Contents Association Conference
• /
• 2006.11a
• /
• pp.372-376
• /
• 2006

현재 심각한 재해에 대한 임박성은 일부 관계자 이외는 감지하지 못하고 있는 것이 현실이다. 재해와 같은 위기에 관한 지식이나 이에 대처하기 위한 기술은 어린 시절부터 습득해 두어야 할 기초적 지식 및 능력이라고 생각한다. 그럼에도 불구하고 대지진 발생이 임박하고 있음을 타인의 일처럼 생각하고 있다는 점은 재해와 같은 위기를 자신의 일처럼 생각하고 어떻게 대처해야 할 것인가에 대해 스스로 생각할 수 있는 기회가 충분하지 않다는 것에서 유래한다. 즉 체계적 실천적인 방재 위기관리교육이 충분하게 실시되지 않고 있다는 점을 지적할 수 있을 것이다. 특히 지역주민의 생명 신체 재산을 보호해야 하는 지방자치단체의 소방담당직원의 실천적 대응능력은 말할 것도 없고 수장(首長)의 리스크 관리능력에 대해 의구심을 가지고 있다. 또한 지역 자체의 방재력 강화라는 관점에서는 자주방재조직 등의 지역방재리더나 지역주민 개개인의 방재능력을 향상시켜야 할 필요성이 강조되고 있다. 최근에 건설된 신관저를 계기로 변화된 방재 위기관리 시스템에 관한 정책적 동향을 살펴본다. 아울러 방재 위기관리에 대한 인재양성을 위한 교육의 일환으로 구축된 e-Learning System인 e-College의 구성 및 관련 내용을 살펴봄으로써 정책적 시사점을 도출하고자 한다. 지방자치단체의 방재 위기관리에 있어서 수장 등 간부직원의 의식과 자세가 지역의 방재력을 크게 좌우하는 것으로 볼 수 있다. 방재담당직원 소방직단원에 대한 교육과제를 들 수 있겠다. 고도로 도시화된 사회가 재해에 대한 취약성이 높아지고 있다. 지역의 방재리더, 재해자원봉사, 주민에 대한 교육과제로 도도부현, 시정촌, 대학에서 방재 위기관리 교육이 실시되고 있지만, 1999년 총리부(總理府)에서 여론조사를 보면 자주방재활동에 참가한 경험이 없는 사람이 전체 70%를 차지하고 있다. 기업에 대한 교육과제로 재해발생시에 사원이나 고객의 안전 확보, 사업의 피해경감 조기복구에 의한 경제에 대한 영향을 경감하기 위한 준비를 충실히 해야 한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.6
• /
• pp.1241-1248
• /
• 2019

In this paper, an auxiliary device was implemented to help blind people more safely from obstacles or risk factors while walking. The ultrasonic sensors detect obstacles in the front, so that the noise gap and the vibration intensity of the buzzer can be heard differently by distance and angle, and so the situation can be perceived by pedestrians. When the ambient light becomes darker than the light intensity set using the CdS resistance value of the light sensor, the LED automatically turns on, makes it easier for pedestrians to recognize the position of the auxiliary device through buzzer if the pedestrian misses the aid using the gyro sensor's slope. Moreover, the location and situation of the blind were transmitted to the caregiver to check safety and behavior using GPS and Bluetooth.

• Journal of Advanced Navigation Technology
• /
• v.14 no.4
• /
• pp.489-494
• /
• 2010

According to the recent increase in air traffic more efficient air traffic control automation is required. Aeronautical traffic environment is different from the common traffic environment since it exist controller for control of aircraft And controller have to control jurisdiction hand-off by manual when aircraft move to the other sector. This paper proposes the automatic control jurisdiction hand-off algorithm for efficient air traffic flow management. It is sector distinction algorithm that aircraft move sector to the other sector it recognized sector and then give permission to authorized controller. As a simulation result, so unlilke simply manual control sector hand-off of existing algorithm. we confirmed that proposed algorithm in this paper can do air traffic control more efficiently by performing automatic aircraft. control sector hand-off.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.7
• /
• pp.1261-1266
• /
• 2017

A random and systematic jitter suppressed delay locked loop (DLL)-based clock generator with a delay-time voltage variance converter (DVVC) and an averaging circuit (AC) is presented. The DVVC senses the delay variance of each delay stage and generates a voltage. The AC averages the output voltages of two consecutive DVVCs to suppress the systematic and random delay variance of each delay stage in the VCDL. The DVVC and AC averages the delay time of successive delay stages and equalizes the delay time of all delay stages. In addition, a capacitor with a switch working effectively as a negative feedback function is introduced to reduce the variation of the loop filter output voltage. Measurement results of the DLL-based clock generator fabricated in a one-poly six-metal $0.18{\mu}m$ CMOS process shows 13.4-ps rms jitter.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.11
• /
• pp.1433-1439
• /
• 2012

This paper introduces a sensor system based on indoor locations in order to implement the Building Energy Management System. This system consists of a thermopile sensor and an ultrasonic sensor. The sensor module is rotated by $360^{\circ}$ and yawed up-and-down by two electric motors. Therefore, it can simultaneously detect the number and location of the inhabitants in the room. It uses wireless technology to communicate with the building manager or the smart-home server, and it can save electric energy by controlling the lighting system or heating/air conditioning equipment automatically. We also demonstrate the usefulness of the proposed system by applying it to a real environment.