• Title/Summary/Keyword: Reduction device

Search Result 1,286, Processing Time 0.03 seconds

Bycatch Reduction by Experimental Shaking Codend Attached with Canvas in a Bottom Trawl

  • Kim, Yonghae
    • Fisheries and Aquatic Sciences
    • /
    • v.18 no.3
    • /
    • pp.325-332
    • /
    • 2015
  • An active stimulating method for juvenile fishes to drive escaping from mesh of the codend was examined by shaking canvas in the bottom trawl followed by shrimp beam trawl. Field fishing trials by a bottom trawl were carried out between the Geomoondo and Jejudo in west of South sea, Korea by conver-net methods to examine the effect on the reduction of juvenile fish as a discard catch by generating a shaking movement of the codend using two pieces of asymmetrical semi-circular canvas. The mean period of the shaking motion with the round canvas was 10-15 s, and the range of amplitude as a vertical depth change was up to 0.4-0.6 m when towing speed 3.4-4.3 k't as estimated by peak event analysis. The escape rate of juvenile fish in conver-net by total juvenile bycatch (codend and cover-net) in 14 trials increased from 20% in a steady codend to 34% using a shaking codend in the bottom trawl, while the marketing catch or total bycatch was similar between steady and shaking cod ends. There was no difference in the body size of the fish and species composition between the steady and shaking cod ends. Above results demonstrate a new method for bycatch reduction actually up to 18% using an active stimulating device, although further experiments are needed to increase an effective shaking motion of the codend in amplitude and period for more bycatch reduction.

Open Reduction of Mandibular Condyle Fracture Via Preauricular Approach (전이개 접근을 이용한 하악 과두 골절의 정복)

  • Kim, Bum-Joon;Cha, Yong-Hoon;Lim, Jae-Hyung;Park, Kwang-Ho;Huh, Jong-Ki
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.32 no.6
    • /
    • pp.521-528
    • /
    • 2010
  • Purpose: Anatomical reduction of the fractured condylar process is an important prerequisite for re-establishing function. The authors reported about effectiveness of transoral approach for mandibular subcondyle fracture using trochar device in cases that the fracture line is below the reference line, the perpendicular line of the longitudinal axis of condylar process passing the lowest point of sigmoid notch. As a serial study, we report the open reduction via preauricular approach for mandibular condyle fracture, in cases that the fracture line is above the reference line. Patients and Methods: Sixteen condylar fractures of 15 adult patients were divided two groups and treated by open reduction via preauricular approach (8 cases) or by closed reduction (8 cases). The degree of maximal mouth opening, occlusion, anatomical reduction, condylar resorption and complications were assessed and evaluated for the two groups. Results: The open reduction of condyle via preauricular approach leads to good results without permanent complications. Anatomical reduction of open reduction group and maximal mouth opening range of the closed reduction group is significantly better than the other group. No significant differences were found in the condylar resorption and the occlusion. Conclusion: The preauricular approach was useful to reduce and fix the condylar fragment, in cases that the fracture line is above the reference line.

The Effect of Stress Reduction of Human Body by the Vibroacoustic Equipment (음향진동장치에 의한 인체의 스트레스 저감 효과)

  • Moon, D.H.;Kim, Y.W.
    • Journal of Power System Engineering
    • /
    • v.11 no.2
    • /
    • pp.32-37
    • /
    • 2007
  • The present study describes the effects of music and vibroacoustic stimuli to the relaxation of human body. We have carried out the experiment on 6 human subjects of which are composed 3 men and 3 women. We have investigated the electroencephalogram(EEG) of all subjects before and after the stimuli of which are made a strong noise or the meditatiom music and the acoustic vibration. The vibroacoustic device has transmitted meditation music as vibration between 20Hz and 250Hz to the body. From the experimental results, we made sure the effects that the meditation music and vibroacoustic stimuli influenced the stress reduction of human body for good as alpha wave was increased continuously during the good stimuli and after that.

  • PDF

An airflow analysis for the reduction of disk flutter in HDD (HDD의 디스크의 진동 감쇄 설계를 위한 공기흐름해석)

  • Kwon, Seong-Min;Koo, S.C.;Kang, Seong-Woo;Hwang, Tae-Yeon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2002.11b
    • /
    • pp.375-380
    • /
    • 2002
  • As the data storage device market demands higher data transfer rate with higher track density. TMR budget is to be tighter so that even minor improvement is sought in HDD development fields. Disk flutter associated with the turbulent air flow inside the chamber becomes of great interest for the reduction of PES especially at OD. A comparative transient turbulent flow study is presented in this paper for the reduction of disk flutter with different housing designs.

  • PDF

Analysis of the Case on Kitchen Equipment of Hotel Adopted Pattern Systemic Layout Planning(SLP) - Focusing on Cooking Process - (체계적 배치(SLP)기법을 적용한 호텔주방 설비배치의 사례분석 - 조리공정을 중심으로 -)

  • 조성호
    • Culinary science and hospitality research
    • /
    • v.9 no.2
    • /
    • pp.98-114
    • /
    • 2003
  • This paper is written to analyze systematically the varieties of informations about cooking stream procedure on the basis of the basic theory of installation and arrangement such as SLP(Systemic Layout Planning) and to deduce the plan for the device, installation and arrangement suitable to cooking stream procedure. Through the substantial improvement in the modeling of hotel L, the optimization of the capacity of installation and arrangement, and the reduction of food resource stream and its movement and through the analysis of cooking stream procedure by disposing and dividing the main kitchen into three individual ones, the improvement of productivity in comprehensive cookery such as the specialization and equalization of cooking procedure and improvement effect of the price-reduction. Moreover, as for the problem of arrangement of installation, it was displayed that the effect went up to twice through the flexible production-related systems such as the improvement of arrangement, reduction of cooking preparation time, the standardization of cookery.

  • PDF

An airflow analysis for the reduction of disk flutter in HDD (HDD의 디스크의 진동 감쇄 설계를 위한 공기흐름해석)

  • Kwon, Jeong-min;J. C. Koo;Kang, Seong-Woo;Hwang, Tae-Yeon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2002.11a
    • /
    • pp.341.2-341
    • /
    • 2002
  • As the data storage device market demands higher data transfer rate with higher track density, TMR budget is to be tighter so that even minor improvement is sought in HDD development fields. Disk flutter associated with the turbulent air flow inside the chamber becomes of great interest for the reduction of PES especially at OD. A comparative transient turbulent flow study is presented in this paper for the reduction of disk flutter with different housing designs.

  • PDF

Experimental Study on Flame Stabilization and $NO_{x}$ Reduction in a Non-Premixed Burner with Sawtooth Mixer

  • Fujimoto, Yohei;lnokuchi, Yuzo;Orino, Minoru;Yamasaki, Nobuhiko
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2004.03a
    • /
    • pp.485-490
    • /
    • 2004
  • Sawtooth mixing device used in a non-premixed burner is evaluated for flame stabilization and NO$_{x}$ reduction. Three mixers with different blade angles are tested. Methane is delivered through the fuel jet and air passes through the co-flow annulus. The flame mode changes (attached flame, lifted flame and extinction) against the fuel flow speed are measured, and the stability diagram is drawn. Moreover, by traversing thermocouple and sampling probe in the flame, the distribution of temperature and NO$_{x}$ mole fraction are measured. With the change in blade angle, flame shape, flame stabilization, the distribution of temperature and NO$_{x}$ mole fraction are changed considerably.rably.

  • PDF

FACTS Site Selections in Large Power Systems using Subtransmission System Reduction (대규모 전려계통에서의 하위 송전계통 축약을 이용한 FACTS 위치선정 연구)

  • Jang, Byeong-Hun;Chu, Jin-Bu;Gwon, Se-Hyeok
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.48 no.11
    • /
    • pp.1429-1433
    • /
    • 1999
  • This paper proposes the FACTS site selection method using subtransmission system reduction. A general method which uses the sensitivity of the variation in voltage and reactive power has been used to determine the location of shunt type FACTS device, but there is a difficulty to finding a proper location due to the overestimation of the effect of sub-transmission systems. Therefore, there is a need to reduce sub-transmission system for finding an effective location of shunt type FACTS devices such as SVC(Static Var Compensator), STATCOM(Static Synchronous Compesator), and so on.

  • PDF

New Approach to Reduce Radiated Emissions from Semiconductor by Using Absorbent Materials

  • Kim, Soo-Hyung;Moon, Kyoung-Sik
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.12 no.1
    • /
    • pp.34-41
    • /
    • 2001
  • Semiconductors performing digital clocking are a main source of radiated emission noise. Therefore, the most secure method of reducing emission noise is to reduce emission radiated from semiconductors; an application of an absorber to the surface of semiconductors is one of these methods, too. However, in reality, it is difficult to achieve as much effect of noise reduction as expected by using only absorber. It is confirmed by experiment in this paper that a loop area within chip has no correlation with radiated emission noise and it is clarified why the existing absorber fails to achieve a satisfactory effect of emission noise reduction. Besides, a new type of chip coating absorber has been developed which can cover up to semiconductor out lead by using ferrite coating material of ferrite/epoxy acrylate substance using only permeability loss out of electromagnetic wave reduction characteristics of materials. As a result of evaluating radiated emission noise by applying this coating absorber to semiconductor device, it could be confirmed that emission noise decreased from about 3 ㏈ up to 20㏈ depending on frequency.

  • PDF

A Research of the Characteristics of $Hg_{1-x}Cd_{x}$Te material by using Electro - Chemical Reduction (Electro-Chemical Reduction에 의한 $Hg_{1-x}Cd_{x}$Te재료의 특성 고찰)

  • 이상돈;김봉흡;강형부
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1994.05a
    • /
    • pp.38-41
    • /
    • 1994
  • The method of passivation for protecting the $Hg_{1-x}Cd_{x}$Te surface is important device fabrication process. Because the surface components are highly reactive leading to its chemical and electrical instability. Especially. the material of detecting for infrared radiation, of which composition is x=0.2 or 0.3, is narrow bandgap semi- conductor. The narrow bandgap semi conductors are largely governed by the properties of the semiconductor surface. The narrow bandgap semi-conductors are largely governed by the properties of the semiconductor surface. The electro-chemical processing of $Hg_{1-x}Cd_{x}$Te allows rigorous control of the surface chemistry and provides an in-suit monitor of surface reaction. So electro-chemical reduction at specific potential can be selectively eliminated the undesirable species on the surface and mainpulated to reproducibly attain the desired stoichiometry. This method shows to assess the quality of chemically treated good $Hg_{1-x}Cd_{x}$Te surface.

  • PDF