• Title/Summary/Keyword: On-off Control

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Effect of $CO_{2}$ Gas Packaging on the Shelf-life of Refrigerated Pork Cuts (탄산가스 포장에 의한 신선돈육의 저장성향상에 관한 연구)

  • Kim, Yong-Su;Kim, Yun-Ji;Yoo, Ick-Jong
    • Korean Journal of Food Science and Technology
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    • v.26 no.3
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    • pp.246-249
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    • 1994
  • Shelf-life of pork packaged under $CO_{2}$ was observed and the optimal volume of $CO_{2}$ gas was determined. High gas barrier film, EVOH($CO_{2}$ permiability; 1 $cc/cm^{2}{\cdot}24\;h{\cdot}atm$) was used as packaging material and the volume ratios of sample to $CO_{2}$ of 1 : 1, 1 : 3 and 1 : 5 were tried using the control of vacuum packaged pork. To ev.3luate quality of pork cuts, total plate counts, TBA, color and sensory score were monitored during the storage at $4{\pm}1^{\circ}C$ for 31 days. TPC of vacuum packaged pork increased up to $4.6{\times}10^{6}\;CFU/cm^{2}$ in 24 days while that of $CO_{2}$ gas packaged pork $4.5{\times}10^{5}\;CFU/cm^{2}$ at the same storage period, and it took 7 days more for gas packaged pork to reach the same TPC count. There was no significant difference in TBA value between vacuum packaged and gas packaged pork. In the color L and a values were not affected by treatment but vacuum packaged pork cuts showed higher b value than gas packaged pork. According to sensory evaluation, gas packaged pork showed less off flavor, better flavor and freshness than vacuum packaged one (P<0.05).

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Conceptual Source Design and Dosimetric Feasibility Study for Intravascular Treatment: A Proposal for Intensity Modulated Brachytherapy (혈관내 방사선치료를 위한 이론적 선원 설계 및 선량적 관점에서의 적합성 연구: 출력변조를 이용한 근접치료에 대한 제안)

  • Kim Siyong;Han Eunyoung;Palta Jatinder R.;Ha Sung W.
    • Radiation Oncology Journal
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    • v.21 no.2
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    • pp.158-166
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    • 2003
  • Purpose: To propose a conceptual design of a novel source for intensity modulated brachytherapy. Materials and Methods: The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a $^{90}Sr/Y$ Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quater of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. Results: The preliminary hypothetical simulation and optimization results demonstrated the 87$\%$ difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7$\%$ by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. Conclusion: The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter.

Spherical and Aspherical RGP Lens Fitting to Epithelium and Endothelium of Rabbit's Cornea -Scanning Electron Microscopy (구면과 비구면 RGP 렌즈 장기 착용시 각막 상피, 내피에 미치는 영향-주사전자현미경적 관찰)

  • Kim, In-Suk;Ryu, Gun-Chang;Chae, Soo-Chul;Jeon, Chang-Jin
    • Applied Microscopy
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    • v.36 no.3
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    • pp.227-234
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    • 2006
  • To investigate the comparative effect of spherical and aspherical RGP lens were worn during 3 weeks on rabbit's cornea. Four white rabbits were worn right eyes with spherical lens and 4 white rabbits were worn right eyes with aspherical RGP lens. Left eyes were served as control. The rabbits were sacrificed at 3 weeks after fitting and observed morphological changes by scanning electron microscopy and also investigate proliferation rate of the corneal epithelium with RGP wearing. After spherical RGP lens wearing, the epithet layer damaged compared to aspherical lens. The superficial cell layer strip off seriously, cell size significantly changed abnormal. Both spherical and aspherical RGP lens fitting group showed so many bacteria and back surface of lens was found like a fern shape. The aspherical RGP lens original material type was some formal than spherical lens. We thought that these pattern was significantly altered with spherical lens by prohibited transmitter oxygen from atmosphere therefore the epithelium shape was changed. This suggested wearing the aspherical lens might be less physiologic than shperical lens fitting.

Efficacy of Enrofloxacin and Silver Sulfadiaznine Topical Otic Suspension for the Treatment of Canine Otitis Externa (개 외이염에 대한 Enrofloxacin과 Silver Sulfadiazine 국소제제의 치료효과)

  • Bae, Seulgi;Kim, Byeongmok;Choi, Sungwon;Sin, Hui-Ju;Lee, Young-Ju;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.30 no.3
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    • pp.172-177
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    • 2013
  • The aim of this study was to evaluate the in vivo and in vitro efficacy of enrofloxacin-silver sulfadiazine (Baytril$^{(R)}$ otic, Bayer, USA) for the treatment of otitis externa in dogs. Twenty-four dogs with otitis externa were included in this double-blinded, randomized study. The experimental group was treated with the Baytril$^{(R)}$ otic and the distilled water was applied to the control group. Both groups were administered each solution twice daily for 7 days and next 7 days off treatment. On days 0, 7 and 14, clinical signs, bacteriological and fungal counts were graded using semi-quantitative scales, respectively. For the evaluation of in vitro efficacy of Baytril$^{(R)}$ otic, we also performed Minimal Inhibitory Concentration (MIC) test by agar dilution method against Staphylococcus pseudintermedius, Pseudomonas aeruginosa and Malassezia pachydermatis. In the experimental group, the sum of clinical scores was decreased 81.0% and microbial scores were significantly reduced 87.0% at days 14, compared with day 0. The results of MIC testing were showed the concentration of enrofloxacin and silver sulfadiazine in Baytril$^{(R)}$ otic is high enough to kill for 3 infectious agents. No adverse reactions were observed in any of the dogs during this study. These results suggest that Baytril$^{(R)}$ otic are efficient and safe treatment for canine otitis externa.

Antioxidant Activity and Quality Characteristics of Pork Patties Added with Saltwort (Salicornia herbacea L.) Powder (함초(Salicornia herbacea L.)분말을 첨가한 돈육패티의 항산화활성 및 품질특성)

  • Joo, Shin Youn;Choi, Hae Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.8
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    • pp.1189-1196
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    • 2014
  • This study investigated the effects of saltwort powder on the antioxidant activity and quality characteristics of patties added with saltwort powder. Patties were prepared with different amounts (0, 1, 2, and 3%) of saltwort powder. The total phenolic content, DPPH free radical scavenging activity, and pH of patties increased with increasing saltwort powder content (P<0.05). In particular, the moisture content and cooking loss of the group added with 2% saltwort powder were the highest and lowest, respectively (P<0.05). As the content of saltwort powder increased, $L^*$ and $a^*$ values decreased while $b^*$ value increased. Texture analysis showed that the hardness, chewiness, and gumminess of the control group were lower than those of the treated group (P<0.05). Consumer acceptability showed that 1% and 2% saltwort powder groups scored higher in terms of overall preference, appearance, color, taste, and texture compared to the other groups. Characteristic intensity rating of saltwort patties showed that as more saltwort powder was added, saltwort taste intensified; however, the increase did not affect juiciness, off flavor, or salty taste of the patties. Judging from the results, it was concluded that the addition of saltwort powder to patties in processing can enhance the preference, quality, and antioxidant activities of the patties, which elevates the value of patties.

A Study on Fire Resistance and Spalling of HPC Beam with Fiber-Cocktail in ISO Fire under Loading Condition (표준화재 재하조건하에서 Fiber Cocktail을 혼입한 고강도 콘크리트 보의 폭렬특성 및 내화성능에 관한 연구)

  • Cho, Kyung-Suk;Kim, Heung-Youl;Kim, Hyung-Jun
    • Fire Science and Engineering
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    • v.23 no.6
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    • pp.126-134
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    • 2009
  • In an attempt to control the spalling in high strength concrete, spalling reducer was mixed to identify the effect and thermal characteristics of concrete beam member at high temperature. The member was manufactured in such as way of adding 40~60MPa of high strength concrete into spalling reducer, and then fire resistance performance were monitored under the ISO standard fire load condition in accordance with KS F 2257. As a result of test, fore rate performance of 40MPa beam without spalling reducer was 180minutes, 50MPa was 174minutes and 60MPa was 152minutes, indicating that 50MPa and 60MPa beam appeared 6~28minutes short to become a 3-hour rate. However, 50 and 60MPa beam mixed with spalling reducer appeared to have satisfied the requirements for 180minutes. A spalling was occurred in surface of 50 and 60MPa beam mixed without spalling reducer, while no spalling or surface failure was occurred with 50 and 60MPa beam mixed with spalling reducer. Thus polypropylene fiber mixed with the concrete proved to be effective, but viewing that the surface of 60MPa was peeled off partially, the steel fiber mixed appeared not to be effective for the beam more than 60MPa.

Greenhouse Gas Reduction from Paddy by Environmentally-Friendly Intermittent Irrigation: A Review (환경 친화적인 간단관개를 통한 논에서의 온실가스 저감)

  • Choi, Joongdae;Uphoff, Norman;Kim, Jonggun;Lee, Suin
    • Journal of Wetlands Research
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    • v.21 no.1
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    • pp.43-56
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    • 2019
  • Irrigated and flooded rice paddy contributes to the greenhouse gas emissions (GHG) that affect climate. This in turn affects the supply and reliability of the water needed for rice production. This dynamic makes current rice production methods foreseeably less sustainable over time while having other undesirable effects. Intermittent irrigation by a means of the system of rice intensification (SRI) and alternate wetting and drying (AWD) methods was reviewed to reduce global warming potential (GWP) from 29% to 90% depending on site-specific characteristics from flooded rice paddy and analyzed to be a promising option for enhancing the productivity of water as well, an increasingly constraining resource. Additional benefits associated with the SRI/AWD can be less arsenic in the grain and less degradation of water quality in the run-off from rice paddies. Adoption and expansion of intermittent irrigation of SRI/AWD may require costly public and private investments in irrigation infrastructure that can precisely make irrigation control, and the involvement and upgrading of water management agencies and farmer organizations to enhance management capabilities. Private and public collaboration as a means of earning carbon credit under the clean-development mechanism (CDM) with SRI/AWD for industries to meet as a part of their GHG emission quota as well as a social contribution and publicity program could contribute to adopt intermittent irrigation and rural investment and development. Also, inclusion of SRI and AWD in programs designed under CDM and/or in official development assistance (ODA) projects could contribute to climate-change mitigation and help to achieve UN sustainable development goals (SDGs).

Changes in Total Plate Counts and Quality of Pig Small Intestine by Different Washing and Packaging Methods

  • Kang, Geunho;Seong, Pil-Nam;Ba, Hoa Van;Moon, Sungsil;Cho, Soohyun;Park, Beom-Young;Kang, Sun-Moon;Ham, Hyoung-Joo;Kim, Dayae;Park, Kyoungmi
    • Food Science of Animal Resources
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    • v.38 no.6
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    • pp.1253-1260
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    • 2018
  • Pig small intestine not only is used as food but also for sausage casings production in many countries worldwide. However, it is well recognized that the small intestine is important source of spoilage and pathogenic bacteria. The present study aimed at investigating the effects of different washing and packaging methods on the changes of microbial levels and physicochemical characteristics of pig small intestine. After collecting and trimming off of visible fats, the pig small intestine samples were treated with; (i) different packaging methods: aerobic packaging (AP), skin packaging (SP), and vacuum packaging (VP); and (ii) washing with different concentrations of acetic acid. The treated samples were then stored at $4^{\circ}C$ for 1, 4, 7, and 10 d. At 1-d storage, higher pH value was found in the AP-treated samples, however, after 7 to 10 days the samples treated with SP had higher values compared to the ones treated with AP and VP (p<0.05). Thiobarbituric acid reactive substances values were higher in the AP-treated samples than those of the SP- and VP- treated samples at 7-d storage (p<0.05). At $10^{th}$ d, total plate counts (TPC) were higher in the control than in the acetic acid-washed samples (p<0.05). Additionally, the TPC was lower in the SP- and VP-treated samples than the AP-treated samples at 7-d storage (p<0.05). These obtained results suggest that the applications of washing with acetic acid solution and/or SP and VP methods could be an effective way to extend the shelf-life of pig small intestine during cold distribution.

A Study on the Environmentally-friendly Design Techniques Extract and Applying Modern of Traditional Residential Area - The Case of Dokrakdang in Kyungbuk Province - (전통주거공간의 환경친화적 설계기법 추출 및 현대적 적용 - 경상북도 독락당을 사례로 -)

  • Heo, Jun;Song, Byeong Hwa
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.2
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    • pp.63-72
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    • 2011
  • The aim of this study, a traditional residential area in the environmentally friendly design techniques to identify the techniques and principles that have been carried out to reestablish the principles. To do this, through literature review environmental performance is reflected in the traditional residential area side of resources conservation, locational aspects, spatial configuration, and how cases were selected looking for ways to apply modern. Are examples of upper class housing in the Chosen Dynasty Period period construction relatively well-preserved round and a good building with a clear housing Dokrakdang year were selected. Locational aspects of the terrain with minimal changes to the building and construction techniques were entirely in terms of environmental conservation and environmental temperature was adjusted to regulate the room temperature technique could be seen. In terms of cycling in natural materials were recycled. and water make used of positive through water cycling technique & water control. In addition, the importance of landscape views overlooking the landscape from inside to outside through the regulation of the various internal and external space technique was used to attract and expand. Traditionality in the pursuit of modern space, simply cut off because of tradition rather than to restore or recover the organizing principle inherent in the traditional space, and extraction of the contemporary social, cultural and environmental understanding of space is acceptable in basis. Environmentally-friendly design techniques in a traditional residential area for a long time to be developed by the experience of its application of modern environmental and energy problems and pleasant environment to the creation of human life and are subject to significant swings in that.

Control Method for the Number of Travel Hops for the ACK Packets in Selective Forwarding Detection Scheme (선택적 전달 공격 탐지기법에서의 인증 메시지 전달 홉 수 제어기법)

  • Lee, Sang-Jin;Kim, Jong-Hyun;Cho, Tae-Ho
    • Journal of the Korea Society for Simulation
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    • v.19 no.2
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    • pp.73-80
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    • 2010
  • A wireless sensor network which is deployed in hostile environment can be easily compromised by attackers. The selective forwarding attack can jam the packet or drop a sensitive packet such as the movement of the enemy on data flow path through the compromised node. Xiao, Yu and Gao proposed the checkpoint-based multi-hop acknowledgement scheme(CHEMAS). In CHEMAS, each path node enable to be the checkpoint node according to the pre-defined probability and then can detect the area where the selective forwarding attacks is generated through the checkpoint nodes. In this scheme, the number of hops is very important because this parameter may trade off between energy conservation and detection capacity. In this paper, we used the fuzzy rule system to determine adaptive threshold value which is the number of hops for the ACK packets. In every period, the base station determines threshold value while using fuzzy logic. The energy level, the number of compromised node, and the distance to each node from base station are used to determine threshold value in fuzzy logic.