• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.13 no.5
• /
• pp.422-428
• /
• 1988

An iterative learning control system is a control system which makes system outputs follow desired outputs by iterating its trials over a finite time interval. In a discrete time system, we proposed one method in which present control inputs can be obtained by a linear combination of the input sequence and time-shifted error sequence at previous trial. In contrast with a continous time learning control system which needs differential opreration of an error signal, the time shift operation of the error sequence is simpler in a computer control system and its effectiveness is shown by a simulation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2002.02a
• /
• pp.600-606
• /
• 2002

이제까지 전자코 시스템을 이용하여 각각의 식용유에 대한 가열시간과 가열온도에 대한 특성을 분석하였다. 전자코시스템의 센서에서 출력되는 $R_{gas}$/ $R_{air}$를 그래프분석을 통하여 센서가 반응하는 성향을 알 수 있었다. 그리고 주성분 분석의 score plot을 이용하여 PCI의 0을 중심으로 (+)영역에서 가열시간이 짧게 나타나고, (-)영역에서는 가열시간이 길게 나타나는데 이는 가열 시간에 따른 신선도를 예측 할 수 있음을 시사하였다. 그리고 주성분 분석의 loads plot을 이용하여 비슷한 향 성분에 반응하는 각 센서의 성향을 파악 할 수 있었다. 마지막으로 군집분석을 통하여 각 식용유의 종류와 가열온도와 가열 시간에 따른 센서의 상사성을 이용하여 전자코 시스템의 설계에 있어 식용유의 향 특성에 맞는 센서를 선택 시 유용하게 이용 될 것으로 사료된다. 결과적으로 전자코 시스템은 식용유의 유통과 소비과정에서 흔히 발생되는 휘발성 향 특성을 이용하여 가열시간에 따른 식용유의 품질관리와 품질 검사를 비롯한 신선도를 예측할 수 있으며 이를 이용하여 제조 및 유통 그리고 조리 과정에서 보다 효율적으로 사용 될 것으로 예상된다.상된다.

• The Journal of the Acoustical Society of Korea
• /
• v.25 no.6
• /
• pp.257-268
• /
• 2006

To determine the faults of ceramic cup it is proposed to use pseudo reverberation time concept estimated by impact test in room. Schroeder curves estimated from impact test for a cup with small crack and without one are utilized to estimate pseudo reverberation time. Pseudo reverberation times are compared and discussed according to a sort of impact hammers and impact points and also boundary conditions. As a result. proposed method is proved to be very useful to detect the existence of faults for candidate cups.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.4
• /
• pp.63-68
• /
• 2010

The Color Management System in recent printers adopts ICC profiles for both monitors and printers. However, the ICC profile doesn't contain the characteristics of reproduced color on each monitor, because the color on each monitor is changed by user adjustment such as color temperature, brightness, and contrast adjustment. It is also depended on the backlight type and lifetime. As a result, unwanted color is reproduced on the printed paper, not like that on the monitor. To overcome the color difference between monitors and printers, it is needed to control the information of ICC profile. That is, first, the ICC profile is generated by the measurement of monitors having user set, then, through the CMS, the color on monitors can be produced on printed paper. However, it is difficult to apply the above system for normal users due to absence of measuring equipment and time consuming process. Therefore, this paper proposes a novel color matching technique based on the estimation of condition for each monitor having user set. The estimation is performed by a simple comparison visual test using a test image on printed paper and monitor. Then, the condition of monitor is applied to the ICC profile. As a result, the new ICC profile contains the color difference between user monitor and printer. The experimental results show the printed images using our proposed method have almost similar color with those on monitors.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.7
• /
• pp.4692-4697
• /
• 2014

A micro-grid including photovoltaic source and Li battery has been installed and operated for several years at the campus of USF and been used as a test bed. Photovoltaic power source has been strongly influenced by the location, weather and climate of the installed area. To compensate for the uncertainty of photovoltaic source's power output, a Li battery is connected directly to the photovoltaic source and supplies electric power to the grid. The Li battery is operated to supply power output to the grid according to the charging or discharging mode of the battery based on the average power output of the photovoltaic source, which is calculated from the monitored data for several years. The grid of the photovoltaic and Li battery system is operated as a severe loading condition and the operating characteristics of PV source and Li battery cells are analyzed in detail.

• Journal of the Korean Electrochemical Society
• /
• v.15 no.3
• /
• pp.115-123
• /
• 2012

As the market of lithium secondary batteries moves from mobile IT devices to large-format electric vehicles or energy storage systems, the strengthened battery specifications such as long-term reliability longer than 10 years, pack-level safety and tough competitive price have been required. Moreover, even though high power properties should also be achieved for hybrid electric vehicles, it is not easy to measure accurate power values at various conditions. Because it is difficult to choose a proper measurement method and its experimental condition is more complex comparing to capacity measurement. In addition, the power values are very sensitive to power duration time, state-of-charge (SOC) of cells, cut-off voltages, and temperatures, whereas capacity values are not. In this paper, we introduce three kinds of power measurement methods, hybrid pulse power characterization (HPPC) suggested by US FreedomCar, so-called J-pulse by Japan electric vehicle association standards (JEVS) and constant power measurement, respectively. Moreover, with pouch-type unit cells for HEV, experimental power data are discussed in order to compare each power measurement.

• Korean Journal of Optics and Photonics
• /
• v.17 no.1
• /
• pp.60-67
• /
• 2006

We constructed a TEA $N_2$ laser which consists of spark gap, pulse type high voltage power supply, Blumlein transmission line circuit, laser tube with Ernst electrode. We observed the self-preionization with an optical fiber in the spark gap and laser tube. The higher voltage power supplied to the Blumlein transmission line circuit, the better preionization was. An U-type transformer yielded better stability and output power than an I-type transformer. The discharge time after triggering a spark gap for the U-type transformer was also short. We obtained the stability of $2.7\%$ and output power of $36{\mu}J$ when the optimum conditions of the laser operation were spark gap distance of 6.0 mm, electrode distance in laser tube of 5.0 mm, $N_2$ gas flow rate in spark gap of 1500 cc/min, $N_2$ gas flow rate in laser tube of 4 ${\iota}$/min, output window reflectivity of $40\%$ and repetition rate of 10 Hz.

• The KIPS Transactions:PartA
• /
• v.19A no.1
• /
• pp.45-50
• /
• 2012

The demand for faster execution time and lower energy consumption has compelled architects of embedded processors to customize it to the needs of their target applications. These processors consequently provide a rich set of specialized instructions in order to enable programmers to access these features. Such an instruction is typically a $multi$-$output$ $instruction$ (MOI), which outputs multiple results parallely in order to exploit inherent underlying hardware parallelism. Earlier study has exhibited that MOIs help to enhance performance in aspect of instruction counts and code size. However the earlier algorithm does not consider the register pressure. So, some selected MOIs introduce register spill/reload code that increases the code size and instruction count. To attack this problem, we introduce a novel iterated instruction selection algorithm based on the register pressure of each selected MOIs. The experimental results show the suggested algorithm achieves 3% code-size reduction and 2.7% speed-up on average.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.12
• /
• pp.96-105
• /
• 2009

Photovoltaic array distance will be calculated that can have maximum output through the rearrangement of photovoltaic array by comparing and analyzing the power output decrease from the shadows of photovoltaic arrays according to the consideration of incidence angle that is not suitable to the situation of our country among the causes of power output decrease by sampling photovoltaic power generation plants. When relocate simulation result photovoltaic array 1 line, when relocate about 2.8[%], photovoltaic array 3 lines when relocate about 1.2[%], photovoltaic array 2 lines, output of about 5.0[%] improved. Also, gained space gains of photovoltaic array party 1.29[m] when relocate photovoltaic array party 0.82[m], 3 lines when relocate photovoltaic array party 0.39[m], 2 lines when relocate 1 line. As gains occur on photovoltaic array clearance, time that receive effect of shade was slowed down gradually and showed result that elevation of output shows finally.

• Korean Journal of Optics and Photonics
• /
• v.35 no.2
• /
• pp.49-60
• /
• 2024

We analyze the number of phase screens required for the simulation of a high-energy laser beam's propagation over an atmospheric channel. For high-energy lasers exceeding tens of kilowatts (kW) in power, the laser beam is mainly affected by atmospheric turbulence and thermal blooming. When using the split-step method to implement losses due to atmospheric absorption and scattering and distortion of the beam due to turbulence and thermal blooming, the number of phase screens is a critical factor in determining the accuracy and time required for the simulation. By comparing simulation results obtained using a large number of phase screens (e.g., 150 screens) under a wide range of atmospheric turbulence conditions, we provide new guidelines for the number of phase screens required for simulating the beam propagation of a high-power laser below 2.5×10⁶ W/m² (e.g., a 500-kW laser beam having a 50-cm diameter).