• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.8
• /
• pp.598-605
• /
• 2011

The main object of this study is to investigate the Dust Collection Characteristics of multi-layer multi-stage porous plate system with polarization charging mechanism, experimentally. The experiment is carried to analyze the characteristics of pressure drop and collection efficiency for the present system with the experimental parameters such as applied voltage, inlet velocity, inlet concentration and stage number, etc. In results, the pressure drop becomes 18 to $134mmH_2O$, with increment of stage number (1 to 5) at inlet velocity $v_{in}$ = 3.11 m/s ($v_t$ = 18 m/s) and inlet concentration 3 g/m3 for inflow current. In case of both applied voltage 0 kV and non-inflow current, the collection efficiency of 5 stage is 92.5% at $v_{in}$ = 2.58 m/s ($v_t$ = 15 m/s), while it is estimated that the collection efficiency becomes about 6% higher than that of 0 kV and non-inflow as 98.5% at $v_{in}$ = 2.58 m/s for both alternating polarization charge (applied voltage 2.5 kV) and inflow current system.

• Korean Journal of Weed Science
• /
• v.18 no.4
• /
• pp.295-303
• /
• 1998

The seed dormancy is one of the peculiar characteristics of a number of weed species and it makes difficulties in weed control. To clarify the mechanism of seed dormancy, several chemicals such as $KNO_3$, KOH, thiourea, and $H_2O_2$ and phytohormone($GA_3$) were treated to dormant seeds. Among the species treated with several chemicals, the germination percentages of Setaria glauca, Ambrosia trifida and Ranunculus sceleratus were increased with $KNO_3$ and those of S. glauca, R sceleratus were increased with thiourea. Hydrogen peroxide promoted the germination of Setaria viridis and S. glauca. Germination percentages of S. viridis, S. glauca and Cyperus saraguinolentus were increased with enzyme treatment using pectinase. GA treatment enhanced the geim.ination of Eleusine indica and R sceleratus but the other species were affected slightly. Especially. E. indica showed linearity in the relationship between germination percentage and GA concentration. So, It seemed that E. indica can be used as a bioassy material for GA. Considering the phenological habits of weed species, the seeds were buried under soil for long time(more than 1 month) over winter. When seeds were buried in soil, the degree of dormancy was drastically decreased. Especially, germination of seeds buried were increased under alternating temperature. The germination rates of Persicaria ssp. and Chenopodium ssp. were increased by 50% order alternating temperature after burial for seven weeks.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.10 no.1
• /
• pp.129-145
• /
• 2004

Many physical therapy who graduate department of physical therapy interested in physical therapy specialist. The boundary of physical therapy specialist is consist of 7 parts; CCS(Cardiopulmonary Certified Specialist), ECS(Clinical Electrophysiologic Certified Specialist), GCS(Geriatric Certified Specialist), NCS(Neurologic Certified Specialist), NCS(Neurologic Certified Specialist), OCS(Orthopaedic Certified Specialist), PCS(Pediatric Certified Specialist), SCS(Sports Certified Specialist). So the purpose of this study was to investigate of undergraduate student's interest about the area of special physical therapy and its academy. The data were collected from May 17 to 24, 2004 and 158 valid questionnaires were obtained and analyzed. It was for undergraduate students who major in physical therapy in college and university which are located in Busan, Ulsan and Kyoungnam province. The result is follows: 1. The research about the study of physical therapy after graduation was that 45.5% of female thought that they going to study as possible as they can was the best. In the case of men, 54.3% of male thought that they going to study was the best. 2. The result about recognition of special physical therapy was that 62.0% of people answered CCS, 69.6% of people answered GCS. The most familiar part of special physical therapy at course of school curriculum was that 88.0% of people answered OCS, and 84.2% of people answered NCS. 3. The result about the most interesting part of special physical therapy was that 68.6% of male and 36.1% of female answered OCS. On the other hand, the least part that people doesn't care was that 41.2% of male answered PCS, and 41.0% of female answered CCS. 4. About educational matters of special physical therapy and its academy was that 60% of answered 'Not enough'. An answer to question of special physical therapy and its academy's educational necessity. At the a course of faculty and clinical practice was that 58.9% of answered 'somewhat necessary'. After graduation, study a plan of special physical therapy was that 59.5% of answered 'immediate academy'. 5. Recognize scale in alternation physical therapy, think of extend physical therapy's territory is 'necessary of extend territory' was 78% the highest answer. 57.6% of answered was concerned about alternating physical therapy, and want to study.

• Journal of the Korean Ceramic Society
• /
• v.42 no.3 s.274
• /
• pp.211-217
• /
• 2005

[ $Zn_{1-x}Co_{x}O$ (x=0-0.3) films were grown on Corning 7059 glasses by asymmetrical bipolar pulsed dc magnetron sputtering. The c-axis orientation along (002) plane was enhanced with increasing Co concentration. The $Zn_{1-x}Co_{x}O$ films are grown with fibrous grains of tight dome shape. The transmittance spectra measured from UV-visible showed that sp-d exchange interactions and typical d-d transitions become activated with increasing Co concentration. The electrical resistivity of $Zn_{1-x}Co_{x}O$ films increased with increasing Co concentration, especially it increased greatly at $30at\% Co. X-ray photoelectron spectroscopy and alternating gradient magnetometer analyses indicated that no Co metal cluster is formed and the ferromagnetic properties are exhibited. The low electrical resistivity and room temperature ferromagnetism of $Zn_{1-x}Co_{x}O$ thin films suggested the possibility of the application to Diluted Magnetic Semiconductors (DMSs).

• Journal of the Korean Society for Nondestructive Testing
• /
• v.30 no.5
• /
• pp.464-470
• /
• 2010

The integrity of the industrial equipment in use under high temperature and high pressure must be assessed by regularly measuring the degraded mechanical properties during service time. In order to nondestructively monitor the degraded mechanical properties of industrial equipment, a measuring method of the reversible permeability(RP) using surface type probe is presented. The method for measuring the RP is based on that RP is the differential value of hysteresis loop. The RP is exactly the foundation hatmonics induced in a detecting coil measured by lock-in amplifier tuned to a frequency of the alternating perturbing magnetic field. The peak of RP is measured around the coercive force. Steel material used in this work was 12Cr ferritic heat resisting steel. The eleven kinds of samples aged during different times under same temperature ($700^{\circ}C$) were prepared. Peak interval of reversible permeability(PIRP), Vickers hardness, and tensile strength measured for the aged samples decreased abruptly for short aging time (below 500 h), but the change became small at a long aging time. Vickers hardness and tensile strength linearly decreased as RIRP decreased, so the degraded mechanical properties of 12Cr ferritic heat resisting steel could be nondestructively evaluated by measuring RIRP.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.6
• /
• pp.1229-1244
• /
• 2017

In recent years, as demand for data-based analytical methodologies increases in various fields, optimization methods have been developed to handle them. In particular, various constraints required for problems in statistics and machine learning can be solved by convex optimization. Alternating direction method of multipliers (ADMM) can effectively deal with linear constraints, and it can be effectively used as a parallel optimization algorithm. ADMM is an approximation algorithm that solves complex original problems by dividing and combining the partial problems that are easier to optimize than original problems. It is useful for optimizing non-smooth or composite objective functions. It is widely used in statistical and machine learning because it can systematically construct algorithms based on dual theory and proximal operator. In this paper, we will examine applications of ADMM algorithm in various fields related to statistics, and focus on two major points: (1) splitting strategy of objective function, and (2) role of the proximal operator in explaining the Lagrangian method and its dual problem. In this case, we introduce methodologies that utilize regularization. Simulation results are presented to demonstrate effectiveness of the lasso.

• Journal of the Korean School Mathematics Society
• /
• v.14 no.3
• /
• pp.261-275
• /
• 2011

Seok-Jung Choi's Jisuguimundo mentioned as a brilliant legacy in the history of Korean mathematics had been cloaked in mystery for 300 years. In the meantime there has been some efforts to find solutions, and some particular answers were found, but no one achieved full success mathematically. By the way, H-alternating method showed that to find solutions of Jisuguimundo is possible, even though that method restricted magic number to 88~92 and 94~98. In this paper, $n{\times}n$ Jisuguimundo is defined, and it is showed that finding solutions of it is always possible in case of partition $({\upsilon}+1)+{\upsilon}+({\upsilon}+1)$ & co-partition ${\upsilon}+({\upsilon}+1)+{\upsilon}$, partition $({\upsilon}+1)+({\upsilon}-1)+({\upsilon}+1)$ & co-partition $({\upsilon}-1)+({\upsilon}+1)+({\upsilon}-1)$, partition $({\upsilon}+1)+({\upsilon}+2)+({\upsilon}+1)$ & co-partition $({\upsilon}+2)+({\upsilon}+1)+({\upsilon}+2)$, and partition $({\upsilon}+1)+({\upsilon}+3)+({\upsilon}+1)$ & co-partition $({\upsilon}+3)+({\upsilon}+1)+({\upsilon}+3)$. And It is suggested to find solutions of $n{\times}n$ Jisuguimundo could be used as a task for problem solving.

• Journal of the Institute of Convergence Signal Processing
• /
• v.4 no.1
• /
• pp.15-26
• /
• 2003

Ultrasonic inspection methods are widely used for detecting flaws in materials. The signal analysis step plays a crucial part in the data interpretation process. A number of signal processing methods have been proposed to classify ultrasonic flaw signals. One of the more popular methods involves the extraction of an appropriate set of features followed by the use of a neural network for the classification of the signals in the feature space. This paper describes an alternative approach which uses the least mean square (LMS) method and expectation maximization (EM) algorithm with the model based deconvolution which is employed for classifying nondestructive evaluation (NDE) signals from steam generator tubes in a nuclear power plant. The signals due to cracks and deposits are not significantly different. These signals must be discriminated to prevent from happening a huge disaster such as contamination of water or explosion. A model based deconvolution has been described to facilitate comparison of classification results. The method uses the space alternating generalized expectation maximization (SAGE) algorithm In conjunction with the Newton-Raphson method which uses the Hessian parameter resulting in fast convergence to estimate the time of flight and the distance between the tube wall and the ultrasonic sensor Results using these schemes for the classification of ultrasonic signals from cracks and deposits within steam generator tubes are presented and showed a reasonable performances.

• Korean Journal of Weed Science
• /
• v.8 no.3
• /
• pp.299-307
• /
• 1988

Several experiments were conducted to investigate the effects of external factors on germination and emergence of Eclipta prostrata (L.)L. The weight of viable achenes doubled as a result of 90 minutes soaking in water. The germination of E. prostrata was significantly improved by alternating temperatures. At a constant temperature of $35^{\circ}C$, only 78% of the achenes germination, whereas at alternating temperatures of 35/$20^{\circ}C$, 96.5% of the achenes germinated. E. prostrata was more sensitive than rice to moisture stress. No germination of E. prostrata achenes occurred in the absence of oxygen. No germination of E. prostrata achenes occurred in the dark or when they were exposed to green, blue, and far-red light. Germination of E. prostrata achenes was influenced by the duration of illumination after absorption of water. Ten hours of illumination was needed for maximum germination and 2 hours for 50% germination. No significant changes in germination of E. prostrata achenes were observed between pH 3 and 10. A high tolerance of E. prostrata achenes to salt was observed. Emergence of E. prostrata achenes was greatly affected by planting depth. In the upland soil, 74.0% of the achenes planted on the soil surface germinated, and no emergence was at planting depths of 0.5 cm or greater.

• Korean Journal of Weed Science
• /
• v.3 no.2
• /
• pp.137-142
• /
• 1983

The effects of various factors on germination of dormant Digitaria sanguinalis seeds were studied to obtain the basic informations on establishing an effective control method in upland crops. Germination of dormant seeds was most significantly promoted by light treatment, about 88-89%, and followed by the treatment of alternating temperatures (15 or 20$^{\circ}C$ to 35$^{\circ}C$), showing the similar effects like light. Removal of seed coats also increased germination of dormant seeds by 72%, next to the treatments of light and altering temperature. Potassium nitrate ($KNO_3$) at $10^{-2}M$ and concentrated sulfuric acid ($H_2SO_4$) treatment at the duration of 8 minutes resulted in 20% and 37.8% of germination of dormant seeds, respectively, which were significantly higher than that of the untreated control. Under the conditions of altering temperature, gibberellic acid (GA) at $10^{-3}M$ to $10^{-6}M$, benzylandenin (BA) at $10^{-4}$ to $10^{-7}M$ and their combination had no effect on breaking of dormant weed seeds, and instead inhibited the promotive effects induced by the alternating temperature. However, under the constant temperature at 35$^{\circ}C$ in dark, all these treatments increased germination as much as 20% over the untreated control.