• Title/Summary/Keyword: black start

Search Result 57, Processing Time 0.033 seconds

Short-term grazing behavior of cattle under indoor housing for a new-bred tetraploid ruzigrass (Brachiaria ruziziensis Germain et Everard)

  • Ishigaki, Genki;Nitthaisong, Pattama;Prasojo, Yogi Sidik;Kobayashi, Ikuo;Fukuyama, Kiichi;Rahman, Mohammad Mijanur;Akashi, Ryo
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.31 no.5
    • /
    • pp.748-754
    • /
    • 2018
  • Objective: The preference evaluation of cattle is an important factor for estimation and improvement of the grazing amounts of newly introduced or bred grasses or cultivars in barn. This study was performed to assess the grazing behavior (the amount of grazing and/or the grazing speed) of cattle as indirect method using newly bred Brachiaria ruziziensis tetraploid strain 'OKI-1'(BR) hay as treatment group and Cloris gayana 'Callide' (CG) hay as control group. It also compared the feasibility of using behavioral differences between two groups as one criteria for evaluating preference by Japanese black cattle in barn. Methods: Three experiments were carried out using 12 growing Japanese Black cattle including 6 males and 6 females. In each experiment, the four Japanese Black cattle (2 males and 2 females) were placed in separated stall and allowed to graze BR and CG in manger that was separated into two portions for about 30 min. The position and behavior of the cattle were recorded, and weighed the residual of each gay at 15 and 30 minutes after experiment start. Results: The BR was superior to CG in chemical composition such as protein, fibers and non-fibrous carbohydrate. The cattle, over all, tended to prefer BR over CG in the first half 15 minutes in terms of the time spent and amount of grazing. Additionally, growing cattle exhibited neophilia for BR bred newly. Conclusion: These findings indicated the current approach could be applied for one of criteria to evaluate the preference of hay by Japanese black cattle under indoor housing environment.

The Hearing Ability of Black Rockfish Sebastes inermis to Underwater Audible Sound 2. The Auditory Critical Ratio (수중 가청음에 의한 볼락의 청각 능력 2. 청각 임계비)

  • LEE Chang-Heon;SEO Du-Ok
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.34 no.2
    • /
    • pp.151-155
    • /
    • 2001
  • In order to obtain the fundamental data on the auditory thresholds of fishes for marine ranching, the auditory thresholds of black rockfish Sebastes inermis were measured in the presence of masking noise in the spectrum level range of $73\~83$ dB (0 dB re $1{\mu}Pa/\sqrt{Hz}$) with a classical cardiac conditioning technique. Critical ratios were about $28\~34$ dB at $80\~300$ Hz and $47\~52$ dB at $500\~800$ Hz. The ratio increased almost linearly with increasing frequency to 500 Hz. The noise spectrum level at the start of masking was about 70 dB within the frequency range of $80\~800$ Hz excepting 65 dB at 300 Hz. It means that hearing of the black rockfish is masked in the natural environment with the noise spectrum level above 65 dB. The sound pressure level of $200\~300$ Hz recognized by black rockfish was above 96 dB under the ambient noise and the critical ratio of them was above 26 dB.

  • PDF

The Auditory Critical Ratio of the Black Rock Fish Sebastes Schlegeli (조피볼락의 청각 임계비)

  • Park, Yong-Seok;Lee, Chang-Heon;Kim, Ko-Hwan;Seo, Du-Ok
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.12 no.1
    • /
    • pp.1-10
    • /
    • 2000
  • In order to obtain the fundamental data on the auditory thresholds of fishes for marine ranching, the auditory thresholds of black rock fish Sebastes Schlegeli were measured in the presence of masking noise in the spectrum level range of 73 - 83dB (0dB re $1{\mu}Pa/{\sqrt{Hz}}$) with a classical cardiac conditioning technique. Critical ratios were about 19 - 30dB at 80 - 300Hz and 46 - 54dB at 500 - 800Hz. The ratio increased almost linearly with increasing frequency to 500Hz. The noise spectrum level at the start of masking was about 70dB within the frequency range of 80 - 800Hz excepting 65dB at 300Hz. This suggests that hearing of the black rock fish is masked in the natural environment with the noise spectrum level above 65dB. The sound pressure level of which the signal sound of 100 - 200Hz is recognized by black rock fish under the ambient noise is above 90dB and the critical ratio of them is above 20dB.

  • PDF

A Study on the Feasibility Analysis and Capacity Estimation of BESS for Self-Starting Generators (자체기동발전원으로서 BESS의 활용가능성 분석 및 용량 산정에 관한 연구)

  • Kim, Cha-Nyeon;Yu, Won-Kun;kim, Heon-Tae;Lee, Heung-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.9
    • /
    • pp.1119-1124
    • /
    • 2018
  • So far BESS(Battery Energy storage system) has been widely applied to power systems rapidly. Usually it has been used to regulate the renewable energy output and to adjust the power system frequency. In 2013, EPRI has reported a study of utilizing BESS to replace two black start generators of American Electric Power(AEP) that will be demolished. If the BESS can be used as a self-starting generator, it is possible to shorten the long-distance primary transmission line and shorten the restoration time because BESS is capable of the high-speed start and there is no restriction on the installation position. This paper presents a possibility of using BESS as a self-starting generator by using PSCAD/EMTDC in Korean power systems. Herein, the process to estimated the required capacity of BESS is also presented.

Structure Analyses of Rubber/Filler System under Shear Flow by Using Time Resolved USAXS Method

  • Nishitsuji, Shotaro;Takenaka, Mikihito;Amino, Naoya;Ishikawa, Yasuhiro
    • Elastomers and Composites
    • /
    • v.54 no.2
    • /
    • pp.156-160
    • /
    • 2019
  • The changes in the dispersion of carbon black in liquid polyisoprene under shear flow with time have been investigated by time-resolved ultra small-angle X-ray scattering (USAXS) method. The analyses of USAXS profile immediately after the start of shear flow clarified that the aggregates of carbon black with a mean radius of gyration of 14 nm and surface fractal dimension of 2.5 form the fractal network structure with mass-fractal dimension of 2.9. After the application of the shear flow, the scattering intensity increases with time at the observed whole entire q region, and then the a shoulder appears at $q=0.005nm^{-1}$, indicating that the agglomerate is broken and becomes smaller by shear flow. The analysis by the Unified Guinier/Power-law approach yielded several characteristic parameters, such as the sizes of aggregate and agglomerate, mass-fractal dimension of agglomerate, and surface fractal dimension of the primary particle. While the mean radius of gyration of the agglomerate decreases with time, the mean radius of gyration of the aggregate, mass fractal dimension, and surface fractal dimension don't change with time, indicating that the aggregates peel off the surface of the agglomerate.

Development of an Inexpensive Black Box with Transmission of SOS and Theft Signal for an Agricultural Tractor (도난방지 및 구조신호 전송기능이 있는 저가형 농용트랙터 블랙박스 개발)

  • Kim, YuYong;Shin, Seung-Yeoub;Kim, Byounggap;Kim, Hyung Kweon;Cho, Yongho;Kim, Jinoh
    • Journal of Biosystems Engineering
    • /
    • v.37 no.6
    • /
    • pp.352-358
    • /
    • 2012
  • Purpose: The inexpensive black box system was developed to acquire and save driving information, to give the slope information, and to transmit SOS and theft signal. Method: The device consists of a main micro controller to acquire and save data, a GPS sensor module, a CDMA module, a touch LCD module, a RF (Radio Frequency) ID module, a SD (Secure Digital) card module, an emergency electric power source, a theftproof circuit, and a sensing device. The sensing device consists of a 8 bit micro controller, a accelerometer to detect impulse, two slope sensors to detect roll and pitch angle and a circuit to detect operation of 6 lighting devices. Results: Test results are as follows: 1) a tractor can be start up only with an electronic key (password or RFID card), 2) theft signal was transmitted when a tractor moved without an electronic key, 3) SOS was transmitted at conditions that rollover or crash happened. 4) 5 more than per 1s data are recorded at 5 minute intervals as new file name in SD card. Conclusions: This system can be used to save travelling record, reduce accident, prevent theft and rescue life in the accidents.

TCP Accelerator for DVB-RCS SATCOM Dynamic Bandwidth Environment with HAIPE

  • Kronewitter, F. Dell;Ryu, Bo;Zhang, Zhensheng;Ma, Liangping
    • Journal of Communications and Networks
    • /
    • v.13 no.5
    • /
    • pp.518-524
    • /
    • 2011
  • A high assurance IP encryption (HAIPE) compliant protocol accelerator is proposed for military networks consisting of red (or classified) networks and black (or unclassified) networks. The boundary between red and black sides is assumed to be protected via a HAIPE device. However, the IP layer encryption introduces challenges for bandwidth on demand satellite communication. The problems experienced by transmission control protocol (TCP) over satellites are well understood: While standard modems (on the black side) employ TCP performance enhancing proxy (PEP) which has been shown to work well, the HAIPE encryption of TCP headers renders the onboard modem's PEP ineffective. This is attributed to the fact that under the bandwidth-on-demand environment, PEP must use traditional TCP mechanisms such as slow start to probe for the available bandwidth of the link (which eliminates the usefulness of the PEP). Most implementations recommend disabling the PEP when a HAIPE device is used. In this paper, we propose a novel solution, namely broadband HAIPE-embeddable satellite communications terminal (BHeST), which utilizes dynamic network performance enhancement algorithms for high latency bandwidth-on-demand satellite links protected by HAIPE. By moving the PEP into the red network and exploiting the explicit congestion notification bypass mechanism allowed by the latest HAIPE standard, we have been able to regain PEP's desired network enhancement that was lost due to HAIPE encryption (even though the idea of deploying PEP at the modem side is not new). Our BHeST solution employs direct video broadcast-return channel service (DVB-RCS), an open standard as a means of providing bandwidth-on-demand satellite links. Another issue we address is the estimation of current satellite bandwidth allocated to a remote terminal which is not available in DVBRCS. Simulation results show that the improvement of our solution over FIX PEP is significant and could reach up to 100%. The improvement over the original TCP is even more (up to 500% for certain configurations).

Physicochemical Characteristics of Chokong and Soaking Solution on Soaking Period (담금기간에 따른 초콩과 담금액의 이화학적 특성)

  • Jo, Yong-Jun;Jeong, Yong-Jin;Jang, Se-Young;Seo, Ji-Hyung
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.39 no.2
    • /
    • pp.281-286
    • /
    • 2010
  • Effects of soaking period on physicochemical characteristics of chokong (black soybean picked in brown rice vinegar) and soaking solution were investigated. The pH and soluble solid contents in soaking solution increased rapidly whereas total acidity decreased during the first 4 days of soaking. The sudden drop of color 'L' and 'b' values in soaking solution occurred one day after start of soaking; in contrast, 'a' value increased by 1 day, and then decreased for soaking periods. The strength and hardness of chokong showed a decreasing trend as soaking for a long time, and the values of chokong were lower than those of control (black soybean soaked in water and freeze dried). The protein bands of chokong for soaking appeared only under 24,000 Da of molecular weight by electrophoresis. The content of total amino acids of chokong pickled for 7 days was 86.86 mg%, about 3 times for 28.36 mg% of raw black soybean. The contents of essential amino acids, especially, leucine and phenylalanine increased greatly in chokong. In vitro digestibility for protein was 62% in raw black soybean and 84% in chokong pickled for 7 days. Therefore, these results may assumed that chokong will be good source of amino acids.

Development of New Algorithm for the Analysis of Self-Excitation in Primary Restorative Transmission Systems (시송전 계통에서 자기여자 현상의 새로운 해석 알고리즘 개발)

  • Park S.M.;Lee K.S.;Bai J.C.;Hwang B.H.;Song I.J.;Lee N.H.;Lee H.J.
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.54 no.3
    • /
    • pp.117-121
    • /
    • 2005
  • Power system restoration following a massive blackout starts with re-energizing primary transmission lines at first. Some factors such as Ferranti effect, and line charging reactive power should be considered in this stage. Severe overvoltage may be induced by the Ferranti effect at the lines since it would be usually no load condition. And lack of capacitive reactive power will cause the self-excitation. This paper presents a new precise algorithm to analyze the primary restorative transmission system focused on the two major static overvoltage problems during the early restoration process.

The commercialization of ESS PCS replacing Emergency Generator (비상발전용 ESS(Energy Storage System) 상용화 개발)

  • Park, Minjun;Seo, Jungwon;Hwang, Kwangkyu;Park, Juhyun;Jang, Jeahoon;Kim, Heejung
    • Proceedings of the KIPE Conference
    • /
    • 2016.07a
    • /
    • pp.461-462
    • /
    • 2016
  • 본 논문은 100kW 급 비상발전용 ESS 상용화 개발을 제안한다. 비상발전기란 전력계통이 정지되었을 때 발전장치를 구동시켜 전력을 생산하는 자가발전설비를 말한다. 제안하는 시스템은 2Level 전압형 100kW 급 비상발전용 ESS 로써 정상 시 계통 전원과 동기 운전을 수행하는 계통 연계형 전력변환장치이다. 수배전 수용가에 설치되어 운영이 가능하며 일반적인 ESS PCS 기능인 주파수 조정 (Frequency Regulation), 출력 안정화, 첨두부하 저감 (Peak Shaving), 부하평준화 (Load Leveling), 수요반응 (Demand Response)에 추가하여, 자가발전 (Black Start), 무효전력제어 등의 기능을 적용 하였다. 제안된 100kW 급 비상발전기용 ESS PCS 는 시뮬레이션 및 프로토 타입을 이용하여 성능을 검증하였다.

  • PDF