• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.30-30
• /
• 2011

The wave-cutoff tool is a new diagnostic method to measure electron density and electron temperature. Most of the plasma diagnostic tools have the disadvantage that their application to processing plasma where toxic and reactive gases are used gives rise to many problems such as contamination, perturbation, precision of measurement, and so on. We can minimize these problems by using the wave-cutoff method. Here, we will present the results obtained through the development of the wave-cutoff diagnostic method. The frequency spectrum characteristics of the wave-cutoff probe will be obtained experimentally and analyzed through the microwave field simulation by using the CST-MW studio simulator. The plasma parameters are measured with the wave-cutoff method in various discharge conditions and its results will be compared with the results of Langmuir probe. Another disadvantage is that other diagnostic methods spend a long time (~ a few seconds) to measure plasma parameters. In this presentation, a fast measurement method will be also introduced. The wave-cutoff probe system consists of two antennas and a network analyzer. The network analyzer provides the transmission spectrum and the reflection spectrum by frequency sweeping. The plasma parameters such as electron density and electron temperature are obtained through these spectra. The frequency sweeping time, the time resolution of the wave-cutoff method, is about 1 second. A short pulse with a broad band spectrum of a few GHz is used with an oscilloscope to acquire the spectra data in a short time. The data acquisition time can be reduced with this method. Here, the plasma parameter measurement methods, Langmuir probe, pulsed wave-cutoff method and frequency sweeping wave-cutoff method, are compared. The measurement results are well matched. The real time resolution is less than 1 ?sec. The pulsed wave-cutoff technique is found to be very useful in the transient plasmas such as pulsed plasma and tokamak edge plasma.

• Korean journal of applied entomology
• /
• v.46 no.3
• /
• pp.375-383
• /
• 2007

To find out the affection of the sampling techniques to the result of a faunistic study, we surveyed the insect fauna of the Chungbuk National University (four different sites) for a year, from spring to fall. For each site, four different collecting methods: light trap, net sweeping, pitfall trap, and window trap, were applied and the collecting was done every other week for a total of 16 times. A total of 14 orders and 672 species were collected. 501 species were collected by the light trap, which covers about 75% of the total number of species, turn out to be the most effective, while other methods could only cover 18% or less. On average, only about 30% of the species collected at a given time of collecting were re-collected at the next collecting, which means about 70% of the species collected from the first collecting remains not collected in the next collecting if you collect insects every other week. The result suggests that, in addition to applying diverse collecting methods, frequent sampling, or narrow sample window, is another very important factor for a good representation of species diversity in an insect faunistic study.

• The Korean Journal of Pesticide Science
• /
• v.4 no.2
• /
• pp.50-55
• /
• 2000

Occurrence, Injury aspects and control effect of some chemicals were investigated on tomato in plastic house from 1997 to 1998. Adults trapped by yellow sticky trap and sweeping net were increased from late May abruptly. Survey of population densities by yellow sticky trap was more clear than sweeping net. Damaged leaves were found out all the year round in continuous cropping fields and rate of damaged leaves was below 20% in early April and increased gradually up to 80% level after late May. Otherwise, damaged leaves were appeared from 6 weeks after transplanting in first growing field and then damaged leaves was 80% level in spring culture. In autumn culture, rate of damaged leaves was maintained 80% level from transplanting to harvesting date regardless of cultivation years. Number of adults was trapped from late May and peak was late June but mature larva was $6{\sim}8$ individuals in spring culture. In autumn culture, adult and larval densities was maintained high for 3 weeks after transplanting but begun to decrease from 4 weeks(early September). Chlorfenapyr EC, cyromazine WP and abamectin EC could suppress larval populations of Liriomyza trifolii effectively.

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.187-188
• /
• 2006

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.529-532
• /
• 2012

This paper presents the system modeling, analysis, and controller design and implementation with a inverted pendulum system in order to test robust algorithm for sweeping machine. The balancing of an inverted pendulum by moving pendulum robot like as 'segway' along a horizontal track is a classic problem in the area of control. This paper will describe two methods to swing a pendulum attached to a cart from an initial downwards position to an upright position and maintain that state. The results of real experiment show that the proposed control system has superior performance for following a reference command at certain initial conditions.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.4
• /
• pp.194-202
• /
• 2005

The objective of this paper is to develop a multi-functional hotwire cutting system (MHC) using EPS-foam block or plate as the working material. Because the MHC apparatus employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and a turntable, it allows the easy fabrication of various 3D shapes, such as (1) an axisymmetric shape or a sweeping cross-sectioned pillar shape using the hot-strip in the form of sweeping surface and EPS foam block on the turntable, (2) a polyhedral complex shape using the hotwire and EPS foam block on the turntable, and (3) a ruled surface approximated freeform shape using the hotwire and EPS foam plate. In order to examine the applicability of the developed MHC apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were fabricated on the apparatus.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.243-249
• /
• 2007

I propose the excess noise suppressed optical sensor network using optical CDMA with gain saturated optical amplifier in order to increase number of sensors simultaneously connected to network. Simulation analyses confirm that the maximum number of sensors simultaneously connected to the optical sensor network can be largely increased by increasing the gain of gain saturated optical amplifier owing to the pression of access noises with the assignment of sweeping frequency of optical sensors within 10MHz. In the case of the requested SNR of 20dB and the sweeping frequency of 10MHz, the maximum number of sensors simultaneously connected to the optical sensor network can be increased four times as many as the conventional system.

• Journal of Korean Institute of Industrial Engineers
• /
• v.23 no.1
• /
• pp.147-162
• /
• 1997

When designing workplaces or arranging controls on panel, devices and controls should be placed within the reach of operator's arm or foot to guarantee effective performances. Most of the existing research on the reach volume were based on measurements of a few subject's arm reach, and limited to Caucasian and Chinese populations. Furthermore, reach volume considering foot or trunk motion have not been investigated. Range of human joint motion and that of two degrees of freedom motion are needed to generate reach volume analytically using the sweeping algorithm. However, range of two degrees of freedom motion has not been measured up to now. Therefore, range of two degrees of freedom motion was measured in this research, where 47 college students were participated voluntarily as subjects. The results showed that the motion of one joint can be limited by the motion of another motion, that is to say, the shoulder flexion was decreased significantly when the shoulder was adducted or abducted. Second, new approximate algorithms generating reach volumes were suggested, in which range of two degrees of freedom motion was used as input data. Depending upon the body segment included such as trunk, arm and leg, three types of reach volume were provided, in which the human body was modeled as a multilink system based on the robot kinematics and the sweeping method was employed. Reach volume generated analytically in this study showed statistically reasonable results when compared with that obtained from direct measurement.

• The Korean Journal of Zoology
• /
• v.5 no.1
• /
• pp.13-20
• /
• 1962

1. 1957년 8월 7일부터 18일까지 계룡산에서 고도차분포를 조사하기 위하여 고도별 4 지점에서 과물 (복숭아, 도마도) trap를 사용하여 오전 6시와 오후 6시에 동시에 초파리를 채집하였다. 그리고 sweeping 도 하여 총 33 종을 채집하였는데 다음종들은 높은 지점에서 발견되었다. Microdrosophila purpurata, Mycodrosophila basalis, Parascaptomyz disticha, Scaptomyza aplicalis , Drosophila histrioides, D.difasciata, D.histrio. 그리고 초파리의 성비가 고도에 따라 변동하였음을 관찰하였는데 특히. D. suzukii 는 저지에서 충이 현저히 많았던 것이 700미 고지에서는 거의 1 : 1의 성비를 보여주었다. 300 미높이의 (B) 지점에서 D.lacertosa 와D. Coracina 의 일주기활동은 반대적이었는데 D.lacertosa 는 습도가 높은 아침에 주로 활동하고, D.coracina는 이와 반대로 주로 오후에 활동하고 있음을 알았다. 2. 초파리 집단의 계절적 변동을 조사하기 위하여 1958년 4월부터 11월까지 매일 중순삼일씩 공주잠업시험소구내 상전에서 그리고 동년 5월 터 11월까지는 매일 초순삼일식 계룡산에서 각각 5개의 과물 trap를 설치하고 비교관찰하엿따. 매월 초파리종들의 계절적 변동은 3 표와 4 표에 기재된 바와같다. 특히 D.auraria는 두장소에서 우점종이었는데 공주잠업시험소구내 상전에서는 9월에 최고에 달했고, 계룡산에서는 8월에 최고에 달하는 unimodality를 표시하였다. 3 . 초파리의 일주기활동을 조사하기 위하여1959년 6월부터 10월까지 공주잠업시험소구내 상전에서 매월 2일간씩 2시간마다 채집을 하였다. 이 지방에서 우점종인 D.auraria 는 매월 일주기활동에 있어서 bimodality를 형성하였는데 9, 10월에는 두 peak는 서로 근접되었다. 그리고 6월 26일 2시간마다 sweeping 법으로 채집한 D.auraria의 일주기활동도 비교연구하였는데 거의 같은 현상을 나타냈다.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.127-128
• /
• 2006

In this paper, we propose a novel signaling method using chirp signals in UWB radio with satisfaction of FCC regulation. Chirp signals have been used in many ranging systems such as radar because of its good correlation properties. Because it is important to use broader signal bandwidth in order to get higher precision of the ranging, according to the Cramer-Rao Lower Bound, UWB radio is extremely good as the ranging systems. But, it is very difficult to apply existing chirp signals to UWB, because FCC regulates that the systems operating in UWB radio must occupy signal bandwidth more than 500MHz on the condition of stopping the frequency sweeping. So, we propose multiple chirp signals which can satisfy the regulation of FCC while maintaining chirp signal's properties. The multiple chirp signals which are composed of the sub-chirps modulated by sub-carriers can expand the signal bandwidth with the same principle of OFDM systems. The simulation results show that the BER performance of the proposed multiple chirp signals is identical to that of conventional OFDM when it is applied to data communication, and that the correlation properties of the proposed signals are almost the same with properties as those of single chirp signals whose sweeping bandwidth is the same value with the proposed one.