• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.04a
• /
• pp.597-600
• /
• 2010

소프트웨어 재사용(Software Reuse)은 소프트웨어 생산성을 높이는 방법임에도 불구하고 내장형 소프트웨어 개발 분야에서의 적용은 많은 어려움이 있다. 내장형 소프트웨어는 개발된 소프트웨어의 실행환경이 서로 다르고, 하드웨어 의존성이 높기 때문이다. 국방 분야에서의 내장형 소프트웨어는 보안성이라는 특성상 타 프로젝트의 모범사례를 적용하는 데는 정보 공유의 어려움이 있어 왔다. 본 논문에서는 MIL-STD-498에 기반하여 국방 분야의 내장형 소프트웨어 재사용 프로세스에 관해 연구하고 적용 결과를 제시하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.1540-1542
• /
• 2010

국방분야의 무인지상무기체계(Unmanned Ground Vehicles)는 소프트웨어 결함 발생시 유인무기체계와 달리 응급 조치를 수행할 수 있는 사람이 탑승하지 않기 때문에 임무 수행에 치명적인 영향을 미칠 수 있다. 따라서, 무인지상무기체계에 탑재되는 내장형 SW의 신뢰성 있는 임무 수행을 위한 방법을 필요로 한다. 본 연구에서는 무선 Ad-hoc 네트워크로 연결된 UGV의 SW 결함을 원격으로 진단하고, 치료하기 위한 방법에 대해 연구하였다. 국방분야의 무인무기체계에 탑재된 내장형 SW의 신뢰성을 높이기 위해 적용가능하다.

• Asia Marketing Journal
• /
• v.21 no.1
• /
• pp.23-44
• /
• 2019

A decade has passed since the first generation of Genesis was launched in the U.S. with the plaque of Hyundai-Genesis. Genesis Motors was separated from Hyundai Motor in 2015, and has struggled to have the Genesis stand alone in the competitive U.S. luxury sedan market. The present case study aims to find challenges facing the Genesis, which Hyundai has positioned as a luxury sedan competing against conventional luxury brands such as BMW, Mercedes-Benz, and Lexus; evaluate Genesis Motors' strategic response to meet these challenges; and explore an alternative positioning strategy. Specifically, the present case study addresses barriers against the Genesis' market performance, by focusing on the obstacles rooted in the consumer perception as well as the obstacles that stem from the change in the U.S. automobile industry and the nascent network of the Genesis dealership. Genesis Motors' current strategies are evaluated, and an alternative strategy is explored that is largely based on the American consumers' perceptions of the Genesis vis-a-vis conventional luxury brands and outperforming midsize brands.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.10a
• /
• pp.354-355
• /
• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.10a
• /
• pp.358-359
• /
• 2013

• Transactions of the Korean hydrogen and new energy society
• /
• v.25 no.5
• /
• pp.509-515
• /
• 2014

At the fuel processing system (FPS) of fuel cell vehicle, hydrogen recirculation blower (HRB) is used for the recirculation of remained hydrogen after reaction. In this paper, noise and vibration improvement of HRB is studied by changing design and control. It is checked the campbell diagram and critical speed for stability of rotor, and housing stiffness is improved using simulation of frequency response function (FRF). A method is suggested that can decrease the unbalance amount of the rotor and impeller which main source of noise and vibration. In order to reduce the noise during deceleration of blower, electrical braking is applied and tested the risk impact of durability. Founded the optimum switching frequency of the motor control, and reduced the idle rpm by increasing of aerodynamic performance. The superiority of paper is proved by measurement of the improved product's noise and vibration.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.4
• /
• pp.1540-1551
• /
• 2015

The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensor-based methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10º-30º were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10º-15º, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.6
• /
• pp.837-843
• /
• 2012

Asynchronous motors are widely used in many fields. The various starting methods have been developed for the asynchronous motors which have large power compared to source power. The most popular ways to start the motors are to reduce the voltage of motor's stator or change the resistance fed rotor. It is needed to the specific time to reduce the voltage and change the resistance at a specific step. We call it the switching time. It is very difficult to know the switching time exactly. It varies with different types of motors as well as load characteristics. Thus, this paper focuses on the design and development for the mathematical models of motor and load. And then it is implemented in SIMULINK in order to calculate this time. The simulation results are both compared and discussed in detail so that it can be applied for new system with various motors and loads.

• The Journal of the Korean dental association
• /
• v.52 no.12
• /
• pp.734-743
• /
• 2014

Objectives: By introduced reciprocation motion file in dentistry, dentists benefit simple canal shaping procedure and time-saving. But, reciprocation motion generates uncomfortable vibration to doctors and patients. Because there was no study about this consideration, this study compared vibration pattern and power generated from reciprocation motion motor and conventional rotary motor. Materials & Methods: One conventional rotary motor; X-Smart (Dentsply Maillefer, Ballaigues, Switzerland); and two reciprocating motors; WaveOne Motor (Dentsply Maillefer, Ballaigues, Switzerland) and X-SMART PLUS (Dentsply Maillefer, Ballaigues, Switzerland); were used in this study. Triaxial $ICP^{(R)}$ Accelerometer (Model 356A12, PCB piezotronics, New York, USA) was attached on motor's handpiece head, and was measured tri-axial vibratory acceleration with NI Sound and Vibration Assistant 2009 software (National Instruments, Texas, USA). Mean vibratory acceleration and maximum vibratory acceleration was measured on fixed position and handed position. The results of vibratory acceleration were statistically analyzed using ANOVA and multiple comparisons are made using Turkey's test at p<0.05 level. Results: Reciprocating motors showed higher mean vibratory acceleration and maximum vibratory acceleration than conventional rotary motor (p<0.05). Between reciprocating motors, X-SMART PLUS had lower mean vibratory acceleration and maximum vibratory acceleration than WaveOne Motor (p<0.05). Conclusion: Reciprocating motors generate more vibration than conventional rotary motor. Further study about effect of vibration to dentist and patient is needed. And it seems to be necessary to make a standard about vibration level in endodontic motors.

• Journal of the Korean Magnetics Society
• /
• v.20 no.2
• /
• pp.61-67
• /
• 2010

As a high energy permanent magnet is commonly applied to motors so that small motors have high power capacities, it is also necessary to reduce a cogging torque which causes a noise and vibration in permanent magnet motors. The patterns of cogging torque in permanent magnet motors depend on the magnetic field distributions, so it is possible to reduce a cogging torque by designing a core shapes optimally. But it is known that an optimum design algorithm for reduction of cogging torques is too complicated and the process to get an optimized core shape is time consuming task. In this paper, new simplified core shapes are suggested to reduce a design parameters so that the core shapes to reduce a cogging torques could be obtained with simple computations. The result shows that the cogging torques of permanent magnet motors with this simplified core shapes could be reduced effectively without any loss of average torques.