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A Study on the Oogeneis of False Dace (Pseudorasbora parva) (참붕어 (Pseudorasbora parva)의 난자형성과정에 관한 연구)

  • Kim, Dong-Heui;Lee, Kyu-Jae;Kim, Seok;Deung, Young-Kun
    • Applied Microscopy
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    • v.37 no.2
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    • pp.65-72
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    • 2007
  • The oogenesis and ultrastructure of fertilized egg envelope of false dace were investigated by light and electron microscope. The cytoplasm of false dace oogonia was basophilic and many nucleoli were located at inner side of nuclear membrane. In primary oocytes, yolk vesicles were distributed in marginal area only and egg envelope was not formed on egg outside. In secondary oocyte, the egg envelope was formed and yolk vesicles were increased than that of early stage in cytoplasm. The amount of basophilic substance was decreased. In case of matured egg, thickness of egg envelope and site of egg were increased, basophilic substance was distributed in egg envelope around only. The yolk vesicles were changed to yolk mass in accordance with development. The fertilized egg was of ellipsoidal, adhesive type and yellowish, have a single micropyle in the area of the animal pole. The fertilized egg envelope consisted of three layers, an outer adhesive layer, a middle layer consisting of 6 lamellae alternating layers and an inner electron dense layer. An outer surface of the fertilized egg envelope was arranged by adhesive fibrous structures. In conclusion, it is summarized that the oogenesis of false dace were the increase of cell size, the formation and accumulation of yolk, and decrease of basophilic intensity in cytoplasm. These ultrastructural characteristics of fertilized egg envelope from false dace can be utilized in taxonomy of teleost.

The Oogenesis of Chinese minnow, Leuciscinae, Teleostei (경골어류 황어아과 버들치의 난자형성과정)

  • Kim, Dong-Heui;Chang, Byung-Soo;Jung, Han-Suk;Teng, Yung-Chien;Kim, Seok;Lee, Kyu-Jae
    • Applied Microscopy
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    • v.39 no.3
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    • pp.237-243
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    • 2009
  • Chinese minnow, Rhynchocypris oxycephalus is a teleost belonging to Leuciscinae, Cyprinidae. The oogenesis and ultrastructure of egg envelope in Chinese minnow were investigated by light and electron microscopes. The ovary was of white yellowish and ellipsoidal shape with the major axis 30 mm and the minor axis 7mm. Cytoplasm of oogonia was basophilic and many nucleoli were located at inside of nuclear membrane. In primary oocytes, yolk vesicles were distributed only in the marginal area and egg envelope was not formed on the outside of an egg. In secondary oocytes, the egg envelope was formed and yolk vesicles in the cytoplasm were increased than the earlier stage. The basophilic substance of cytoplasm was changed to acidic. In case of matured egg, thickness of egg envelope and size of egg were increased. The yolk vesicles were changed to yolk mass in accordance with development. The outer surface of egg envelope was covered by microvilli-structures, and had a micropyle on the area of animal pole. Egg envelope consisted with 2 layers, an adhesive outer layer with microvilli-structures and fibrillar inner layer. In conclusion, the oogenesis of Chinese minnow was characterized by the increase in cell size, the formation and accumulation of yolk, and the decrease of basophilic substance in the cytoplasm. The oogenesis of Chinese minnow seems to share common patterns in Cyprinidae, but these ultrastructural unique characters of egg envelope can be utilized in taxonomy of teleost.

Design of a On-chip LDO regulator with enhanced transient response characteristics by parallel error amplifiers (병렬 오차 증폭기 구조를 이용하여 과도응답특성을 개선한 On-chip LDO 레귤레이터 설계)

  • Son, Hyun-Sik;Lee, Min-Ji;Kim, Nam Tae;Song, Han-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6247-6253
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    • 2015
  • This paper presents the transient-response improved LDO regulator based on parallel error amplifiers. The proposed LDO regulator consists of an error amplifier (E/A1) which has a high gain and narrow bandwidth and a second amplifier (E/A2) which has low gain and wide bandwidth. These amplifiers are in parallel structure. Also, to improve the transient-response properties and slew-rate, some circuit block is added. Using pole-splitting technique, an external capacitor is reduced in a small on-chip size which is suitable for mobile devices. The proposed LDO has been designed and simulated using a Megna/Hynix $0.18{\mu}m$ CMOS parameters. Chip layout size is $500{\mu}m{\times}150{\mu}m$. Simulation results show 2.5 V output voltage and 100 mA load current in an input condition of 2.7 V ~ 3.3 V. Regulation Characteristic presents voltage variation of 26.1 mV and settling time of 510 ns from 100mA to 0 mA. Also, the proposed circuit has been shown voltage variation of 42.8 mV and settling time of 408 ns from 0 mA to 100 mA.

The study of improving the performance of lower direction finding ability due to the interfered phase difference of circular array Antennas (원형배열안테나의 위상간섭에 의한 방향탐지 성능저하 개선연구)

  • Chung, Jae-Woo;Kim, Young-Kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.535-539
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    • 2010
  • This paper include to study DoA(Direction of Arrival) for radio collection and monitoring system. The direction finding calculated by applying the CVDF (Correlation Vector Direction Finding) algorithm for the five circular dipole antenna over V / UHF band. To improve the accuracy of direction finding by applying CVDF algorithm needs to obtain ideal phase difference each antennas. However, a circular array antenna phase difference pattern may be distorted on a specific frequency band or to particular direction. The effect of installing each array antennas circularly and the effect of the interference of center pole (located in the center of a circular array antenna mount) may make the distortion of phase pattern. If you use an active antenna instead of passive antenna to obtain good sensitivity, you would measure the more distortion. This paper propose how to change combination of antennas to measure the phase in real-time and how to use antenna beam patterns for minimizing the degradation phenomena at applying simple CVDF algorithm and increasing the direction finding capability.

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Implant Breast Reconstruction Using Porcine Dermal Matrix ($Permacol^{(R)}$): A Comparative Study with Acellular Cadaveric Dermis ($AlloDerm^{(R)}$) (돼지진피조직(Porcine Dermal Matrix, $Permacol^{(R)}$)을 이용한 보형물 유방재건술: 무세포성 사체 진피 (Acellular Cadaveric Dermis, $AlloDerm^{(R)}$)와 비교 연구)

  • Jeong, Bo-Rham;Roh, Tai-Suk;Kim, Young-Seok;Hong, Jong-Won;Rah, Dong-Kyun
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.559-566
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    • 2011
  • Purpose: The use of tissue expander/implant in breast reconstruction using tissue expander-implant is one of the most common surgical procedures. The use of AlloDerm as a sling to reestablish the lower pole of the pectoralis major muscle results a decrease in morbidity compared with more invasive procedures. However the use of AlloDerm is more expensive than other options. We decided to compare AlloDerm with Permacol, which has been safely used in human body reconstruction and is less costly than AlloDerm. Methods: After mastectomy, the inferolateral origin of the pectoralis major muscle was elevated. Either AlloDerm or Permacol was sutured to the chest wall at the level of the previously marked inframammary fold. The lower border of the pectoralis major muscle and the upper portion of the crescent-shaped piece of either AlloDerm or Permacol was sutured together using a tension free technique, and a tissue expander was subsequently inserted into the subpectoral-subAlloDerm (or Permacol) dual pocket. Results: AlloDerm was used in twenty-one patients (28 breasts) and Permacol was used in six patients (11 breasts) for tissue expander-implant breast reconstruction. During the mean follow-up period of 17 months (8~25 months). Two infections (7%) occurred in AlloDerm cases and four infections (36%) occurred in Permacol cases. Conclusion: This study is the first comparison of tissue expander/implant breast reconstruction using AlloDerm and Permacol. The use of Permacol resulted in more postoperative infection compared with the use of AlloDerm. This report is still limited with the small number of cases studied.

Study of Scattering Mechanism in Oyster Farm by using AIRSAR Polarimetric Data (AIRSAR 다중편파 자료를 이용한 굴 양식장 산란현상 연구)

  • Lee Seung-Kuk;Hong Sang-Hoon;Won Joong-Sun
    • Korean Journal of Remote Sensing
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    • v.21 no.4
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    • pp.303-316
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    • 2005
  • Strong radar returns were observed in oyster sea farms, and coherent interferometric pairs were successfully constructed. Tide height in coastal area is possible to be measured by using interferometric phase and intensity of SAR data. This SAR application technique for measuring the tide height in the near coastal zone can be further improved when applied to double bounce dominant areas. In this paper, we investigate the characteristics of polarimetric signature in the oyster farm structures. Laboratory experiments were carried out using Ku-band according to the target scale. Radar returns from vertical poles are stronger than those from horizontal Pole by 10.5 dB. Single bounce components were as strong as double bounce components and more sensitive to antenna look direction. Double bounce components show quasi-linear relation with the height of vertical poles, which implies double bounce is more useful to determine water level than total power. A L-band NASA/IPL airborne SAR (AIRSAR) image was classified into single-, double-bounce, and volume scattering components. It is observed that oyster farms are not always characterized by double bounced scattering. Double bounce is a main scattering mechanism in oyster farms standing above seawater, while single bounce is stronger than double bounce when bottom tidal flats are exposed to air. Ratios of the normalized single to double bounce components in the former and latter cases were 0.46 and 5.62, respectively. It is necessary to use double bounce dominant sea farms for tide height measurement by DInSAR technique.

A Study to Improve the DC Output Waveforms of AFE Three-Phase PWM Rectifiers (AFE 방식 3상 PWM 정류기의 직류 출력파형 개선에 관한 연구)

  • Jeon, Hyeon-Min;Yoon, Kyoung-Kuk;Kim, Jong-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.739-745
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    • 2017
  • Many studies have been conducted to reduce environmental pollution by ships and reduce fuel consumption. As part of this effort, research on power conversion systems through DC distribution systems that link renewable energy with conventional power grids has been pursued as well. The diode rectifiers currently used include many lower harmonics in the input current of the load and distort supply voltage to lower the power quality of the whole system. This distortion of voltage waveforms causes the malfunctions of generators, load devices and inverter pole switching elements, resulting in a large number of switching losses. In this paper, a controller is presented to improve DC output waveforms, the input Power Factor and the THD of an AFE type PWM rectifier used for PLL. DC output voltage waveforms have been improved, and the input Power Factor can now be matched to the unit power factor. In addition, the THD of the input power supply has been proven by simulation to comply with the requirements of IEEE Std514-2014.

Convergence Comparison of Linear Oscillating Electric Machines (리니어 오실레이팅 전기기기의 비교 연구)

  • Jeong, Sung-In;Eom, Sang In
    • Journal of the Korea Convergence Society
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    • v.12 no.12
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    • pp.273-280
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    • 2021
  • This paper presents the results of study of linear oscillating electric machine; Cartesian, cylindrical type with permanent magnet, flux reversal, cylindrical reluctance, and transverse flux type. The focus of the work is the suggestion of the characteristics and design process of propose topology, respectively. First of all, there are five types of the proposed to this study on the basis of the existing literatures; Cartesian type, cylindrical type, flux reversal type, cylindrical reluctance type, and transverse flux type. All topology is achieved using equivalent magnetic circuit considering leakage elements as initial modeling. Cartesian type is investigated by number of phases and number of pole pairs using optimal process. A cylindrical type is described by number of phases and displacement of stroke. The flux reversal type is proposed based on the symmetrical and non symmetrical stator cores of the surface mounted PMs mover, and non slanted PMs and slanted PMs of the flux concentrating PMs mover. A cylindrical reluctance type is studied by the shape of mover teeth in geometric aspect to reduce force ripple and increase magnetic flux. A transverse flux type is considered by dividing the transverse flux electric excited and the transverse flux permanent magnet excited. It is significant that the study gives a design rules and features of linear oscillating electric machine.

Abstruseness of Rimbaud's Barbare : Autotextuality and Meaning (랭보의 「야만」의 난해성 : '자기텍스트성'과 '의미')

  • Shin, Ok-Keun
    • Cross-Cultural Studies
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    • v.43
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    • pp.327-354
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    • 2016
  • Rimbaud's prose poem, Barbare in Illuminations, is known for its abstruseness with regard to forms, themes, metaphors. This paper first analyzes the poem's grammatical structure to make sense of such an inscrutable piece of work, then discusses its autotextuality in order to decipher its meaning by comparison with Rimbaud's other works. Autotextuality, a method of literary interpretation of Rimbaud's prose poem presented by Steve Murphy, refers to the intertextuality between the author's works. Despite some previous researches focusing on the intertextuality of Barbare, previous authors have failed not only to find its meaning but also to determine its significance. The abstruseness of Rimbaud's Barbare is sometimes considered an example of the meaningless of Rimbaud's work. However, examining the textual structure and the autotextuality builds meaning, rather than rendering the work meaningless. Barbare which consists entirely of noun phrases and metaphors means destruction, fusion and the pure power of regeneration in the original context of Rimbaud's work. This poem is Rimbaud's answer to Baudelaire's poetic question, Any of where out of World, and presents a strange scenery that uses 'the eternal female voice' to reach the Vulcan in the North Pole. Interpretation of Barbare could provide a methodology for reading the difficult Illuminations. The kind of analyses used are, for example, analysis of the text, analysis of verbal indicators, autotextuality, and an understanding of the joy and the solitude in the silence of the poem. Understanding Barbare may provide a method of interpreting the abstruseness of Illuminations. Through this approach, we can connect and combine every fragment of the Illuminations, so that we can reconstruct the story and the adventure contained therein.

Bird accidents in Southern Mongolia: a case study of bird electrocution (몽골 남부지역의 야생조류 사고: 감전사를 중심으로)

  • Ganbold, Onolragchaa;Bing, Gi-Chang;Purevee, Erdenetushig;Munkhbayar, Munkhbaatar;Choi, Won-Suk;Jargalsaikhan, Ariunbold;Paik, In-Hwan;Purevdorj, Zoljargal;Jargal, Namsrai;Paek, Woon-Kee
    • Korean Journal of Ornithology
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    • v.25 no.2
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    • pp.94-100
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    • 2018
  • Bird electrocution on contact with electricity lines is well reported and is quite common in Mongolian open areas. We visited 15-kV electricity distribution pole lines in a Southern Mongolian semi-desert region three times in 2017, in April, July, and September, to assess their risks to birds. The carcasses of 45 electrocuted birds representing 12 species were identified from 250 poles (overall mortality rate of 1.12% every 10 km). The majority of these electrocuted birds were endangered Saker Falcon (n=11) and common Black Kite (n=11). The lacks of roosting or perching sites in our study sites (indeed other open areas in Mongolia) may resulted for such high rate bird electrocution. A 751-base pair (bp) cytochrome c oxidase I (COI) gene was amplified for DNA sequence-based identification of carcasses that were difficult to identify directly. Our findings revealed the high electrocution risk for birds in Mongolian open areas, especially for the birds of prey, with relatively low-efficiency electrocution mitigation approaches. The findings also indicate that there is a need for better understanding of the risk of bird electrocution, particularly in the open areas. This will contribute to the conservation of endangered species.