• Title/Summary/Keyword: Combination Key Generation

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An Open Circuit Fault Diagnostic Technique in IGBTs for AC to DC Converters Applied in Microgrid Applications

  • Khomfoi, Surin;Sae-Kok, Warachart;Ngamroo, Issarachai
    • Journal of Power Electronics
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    • v.11 no.6
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    • pp.801-810
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    • 2011
  • An open circuit fault diagnostic method in IGBTs for the ac to dc converters used in microgrid applications is developed in this paper. An ac to dc converter is a key technology for microgrids in order to interface both distributed generation (DG) and renewable energy resources (RES). Also, highly reliable ac to dc converters are necessary to keep converters in continuous operation as long as possible during power switch fault conditions. Therefore, the proposed fault diagnostic method is developed to reduce the fault detection time and to avoid any other fault alarms because continuous operation is desired. The proposed diagnostic method is a combination of the absolute normalized dc current technique and the false alarm suppression algorithm to overcome the long fault detection time and fault alarm problems. The simulation and experimental results show that the developed fault diagnostic method can perform fault detection within about one cycle. The results illustrate that the reliability of an ac to dc converter interfaced with a microgrid can be improved by using the proposed fault diagnostic method.

Research advances in reproduction for dairy goats

  • Luo, Jun;Wang, Wei;Sun, Shuang
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.8_spc
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    • pp.1284-1295
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    • 2019
  • Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.

Practical Biasing Power Analysis breaking Side Channel Attack Countermeasures based on Masking-Shuffling techniques (마스킹-셔플링 부채널 대응법을 해독하는 실용적인 편중전력분석)

  • Cho, Jong-Won;Han, Dong-Guk
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.55-64
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    • 2012
  • Until now, Side Channel Attack has been known to be effective to crack decrypt key such as smart cards, electronic passports and e-ID card based on Chip. Combination of Masking and shuffling methods have been proposed practical countermeasure. Newly, S.Tillich suggests biased-mask using template attack(TA) to attack AES with masking and shuffling. However, an additional assumption that is acquired template information previously for masking value is necessary in order to apply this method. Moreover, this method needs to know exact time position of the target masking value for higher probability of success. In this paper, we suggest new practical method called Biasing Power Analysis(BPA) to find a secret key of AES based on masking-shuffling method. In BPA, we don't use time position and template information from masking value. Actually, we do experimental works of BPA attack to 128bit secret key of AES based on masking-shuffling method performed MSP430 Chip and we succeed in finding whole secret key. The results of this study will be utilized for next-generation ID cards to verify physical safety.

The Trend of System Level Thermal Management Technology Development for Aero-Vehicles (항공기 시스템 레벨 열관리 기술개발 동향)

  • Kim, Youngjin;Son, Changmin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.1
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    • pp.35-42
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    • 2016
  • Modern aircraft is facing the increase of power demands and thermal challenges. In accordance with the application of more electric technology and advanced mission requirement, aircraft system requires increase of power generation and it cause increase of internal heat generation. Simultaneously, restrictions have significantly been imposed to the thermal management system. Modern aircraft must maintain low radar observability and infra-red signature. In addition, new composite aircraft skins have reduced the amount of heat that can be rejected to the environment. The combination of these characteristics has increased the challenges faced by thermal management. In order to mitigate the thermal challenges, the concept of system level thermal management should be applied and new modeling and simulation tools need to be developed. To develop and utilize system level thermal management technology, three key points are considered. Firstly, the performance changes of subsystems and components must be assessed at an integrated thermal system. It is because that each subsystem and component interacts with other subsystems or components and it can directly effects on overall system performance. Secondly, system level thermal management requirements and solutions must be evaluated early in conceptual design process as vehicle and propulsion system configuration decisions are being made. Finally, new component level thermal management technologies must focus on reducing heat generation and increasing the availability of heat sinks.

Stage-wise Combination of Key Factors Affecting Healthcare User Innovation by Using Fuzzy-set Qualitative Comparative Analysis (퍼지집합 질적 비교분석을 통한 의료분야 사용자 혁신 단계별 핵심요인 조합 연구)

  • Lee, Sang-Won;Shin, Juneseuk
    • Journal of Technology Innovation
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    • v.24 no.4
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    • pp.193-219
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    • 2016
  • We examine how combinations of key factors affecting healthcare user innovation vary by innovation stages from idea generation through R&D to commercialization and venturing using a fuzzy-set Qualitative Comparative Analysis (fsQCA) of thirty Korean cases in the healthcare field. Our empirical analysis shows that well-functioning innovation network and easy resource acquisition facilitate ideation of radical user innovation. However, technological capability and governmental support are crucial to make a shift to R&D as well as commercialization stages. Differently, incremental user innovation depends heavily on technological capability of users. Our analysis can provide policy makers as well as corporate innovation mangers with a strategic framework for boosting user innovation along three stages.

A Combination Method of CO2-Narcosis and Cold Treatment for Breaking Diapause of Bombus ignitus and Bombus terrestris Bumblebee Queens

  • Yoon, Hyung Joo;Lee, Kyeong Yong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.28 no.2
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    • pp.58-65
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    • 2014
  • Bumblebees are important pollinators of crops and wildflowers. Bumblebees generally produce one generation per year. One of the key stages for year-round rearing of bumblebees is breaking diapause. To evaluate the effects of a combination method of $CO_2$-narcosis and cold treatment to break the diapause of B. ignitus and B. terrestris queens, we determined whether this method affected their ability to establish a colony after the diapause break. The diapause treatment regimes that were utilized were $CO_2$ ($CO_2$-narcosis), CT-1M (cold treatment at $5^{\circ}C$ for 1 mo), CT-1M-$CO_2$ ($CO_2$-narcosis after cold treatment for 1 mo), CT-2M-$CO_2$ ($CO_2$-narcosis after cold treatment for 2 mo), CT-2M (cold treatment for 2 mo), CT-2.5M-$CO_2$ ($CO_2$-narcosis after cold treatment for 2.5 mo) and CT-2.5M (cold treatment at $5^{\circ}C$ for 2.5 mo). In view of the effects on the colony developmental characteristics of B. ignitus queens, the most favorable diapause treatment was CT-1M-$CO_2$. A combination method of $CO_2$-narcosis and cold temperature treatment yielded better results than that of single $CO_2$-narcosis or cold temperature treatment on the colony development of diapause-broken B. ignitus queens. In the case of B. terrestris queens, we concluded that a combination method of $CO_2$ and cold temperature treatment yielded better results than that of a single cold-temperature (up to 2 mo) treatment. In conclusion, the findings of the present study indicated that the combined application of $CO_2$ and cold temperature was a favorable method for the colony development of diapause-broken B. ignitus and B. terrestris queens compared with only $CO_2$-narcosis or cold temperature treatments. A combination method of $CO_2$ and cold treatment reduced the side effect of $CO_2$-narcosis and shortened the duration of cold treatment by at least 1 mo.

Medium Concentration Influencing Growth of the Entomopathogenic Nematode Heterorhabditis bacteriophora and its Symbiotic Bacterium Photorhabdus luminescens

  • Yoo, Sun-Kyun;Brown, Ian;Cohen, Nancy;Gaugler, Randy
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.644-648
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    • 2001
  • The biological control potential of entomopathogenic nematodes (EPN) can be enhanced by improved culture efficiency. Optimization of the media is a key factor for improving in vitro mass production of entomopathogenic nematodes. This study reports the effect of medium concentration. The medium is a combination of carbohydrates, lipids, proteins, sats, and growth factors, on the growth of Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus liminescens. The overall optimal medium concentration for nematode recovery, hermaphrodite size, bacterial mass, infective juveniles (IJs) yield, and doubling time was 84 g/l. At this concentration rate, the doubling time of IJs production and the biomass of symbiotic bacteria was 1.6 days and 12.8 g/l, respectively. The maximum yield of $2.4{\times}{10^5}IJs/ml$ was attained within a one-generation cycle (eight days). The yield coefficient was $2.8{\times}{10^6}$ IJs/g medium, and the maximum productivity was $3.1{\times}{10^7}$ IJs per day. Medium concentration affected two independent factors, recovery and hermaphrodite size, which in turn influenced the final yield.

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Clinical Features of Oxaliplatin Induced Hypersensitivity Reactions and Therapeutic Approaches

  • Bano, Nusrat;Najam, Rahila;Qazi, Faaiza;Mateen, Ahmed
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1637-1641
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    • 2016
  • Oxaliplatin, a third generation novel platinum compound is the most effective first line chemotherapeutic agent for colorectal cancer (CRC) in combination with 5FU and leucovorin. It is indicated for pancreatic, gastric and testicular cancers combined with bevacuzimab, capecitabine, irinotecan and other cytotoxic agents. However, moderate to severe hypersensitivity reactions (HSR) during or after oxaliplatin infusion usually require cessation of chemotherapy or substitution of the key therapeutic drug which largely interferes with improved patient prognosis. This mini- review showcases recent and accepted opinions/approaches in oxaliplatin induced HSR management. Physicians and oncologists have varying attitudes regarding the decision to rechallenge the patient after an HSR experience, efficacy of desensitization protocols, effectiveness and selection of drugs for premedication and possibilities of cross sensitivity to other platinum agents (e.g. carboplatin). A brief insight into underlying molecular mechanisms and clinical manifestations of oxaliplatin induced HSR is offered. We have also discussed the management of oxaliplatin induced HSR and risk stratification for a successful and complete chemotherapeutic plan.

A Modified Product Code Over ℤ4 in Steganography with Large Embedding Rate

  • Zhang, Lingyu;Chen, Deyuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.3353-3370
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    • 2016
  • The way of combination of Product Perfect Codes (PPCs) is based on the theory of short codes constructing long codes. PPCs have larger embedding rate than Hamming codes by expending embedding columns in a coding block, and they have been proven to enhance the performance of the F5 steganographic method. In this paper, the proposed modified product codes called MPCs are introduced as an efficient way to embed more data than PPCs by increasing 2r2-1-r2 embedding columns. Unlike PPC, the generation of the check matrix H in MPC is random, and it is different from PPC. In addition a simple solving way of the linear algebraic equations is applied to figure out the problem of expending embedding columns or compensating cases. Furthermore, the MPCs over ℤ4 have been proposed to further enhance not only the performance but also the computation speed which reaches O(n1+σ). Finally, the proposed ℤ4-MPC intends to maximize the embedding rate with maintaining less distortion , and the performance surpasses the existing improved product perfect codes. The performance of large embedding rate should have the significance in the high-capacity of covert communication.

Research Trends and Prospects of Reverse Electrodialysis Membranes (역전기투석용 이온교환막의 연구동향 및 전망)

  • Hwang, Jin Pyo;Lee, Chang Hyun;Jeong, Yeon Tae
    • Membrane Journal
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    • v.27 no.2
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    • pp.109-120
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    • 2017
  • The reverse electrodialysis (RED) is an energy generation system to convert chemical potential of saline water directly into electric energy via the combination of current derived from a redox couple electrolyte and ionic potential obtained when cation ($Na^+$) and anion ($Cl^-$) pass through cation exchange membrane (CEM) and anion exchange membrane (AEM) into fresh water, respectively. Ion exchange membrane, a key element of RED system, should satisfy requirements such as 1) low swelling behavior, 2) a certain level of ion exchange capacity, 3) high ion conductivity, and 4) high perm-selectivity to achieve high power density. In this paper, research trends and prospects of ionomer materials and ion exchange membranes are dealt with.