• Title/Summary/Keyword: MD4

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The Effect of Management Disclosure and Analysis on the Stock Crash Risk: Evidence from Korea

  • Lee, A-Young;Chae, Soo-Joon
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.4
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    • pp.67-72
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    • 2018
  • The purpose of this study is to investigate the effect of quality of management discussion and analysis (MD&A) disclosure on stock price crash risk. The MD&A can be seen to reflect the management's intention on public announcement and reveals directly what the management says to communicate with outside investors. A firm's high-quality MD&A implies the management's commitment to communicating with the market, not allowing the managers to have incentives to hoard unfavorable news, which if revealed to the public, may lead to downward stock price corrections, damaging corporate values. The high-quality MD&A is, thus, likely to reduce the stock price crash risk. We use a logistic regression to test whether MD&A influences crash risk using listed companies in the Korean Stock Exchange (KSE) stock market between 2010 and 2013. Findings of the empirical test show that the higher the quality of MD&A, the less likely crash risk appears, implying that the MD&A disclosed adequately can be one of the factors mitigating firm's stock price crash risk. This study has implications as it presents the MD&A disclosure as a factor influencing stock price crash risk and suggests voluntary disclosure as well as mandatory disclosure acts as a variable that explains the risk of stock price crash.

Design of MD5 Hash Processor with Hardware Sharing and Carry Save Addition Scheme (하드웨어 공유와 캐리 보존 덧셈을 이용한 MDS 해쉬 프로세서의 설계)

  • 최병윤;박영수
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.4
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    • pp.139-149
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    • 2003
  • In this paper a hardware design of area-efficient hash processor which implements MD5 algorithm using hardware sharing and carry-save addition schemes is described. To reduce area, the processor adopts hardware sharing scheme in which 1 step operation is divided into 2 substeps and then each substep is executed using the same hardware. Also to increase clock frequency, three serial additions of substep operation are transformed into two carry-save additions and one carry propagation addition. The MD5 hash processor is designed using 0.25 $\mu\textrm{m}$CMOS technology and consists of about 13,000 gates. From timing simulation results, the designed MD5 hash processor has 465 Mbps hash rates for 512-bit input message data under 120 MHz operating frequency.

Studies on the Viability of In Vitro-Matured Bovine Oocytes Vitrified by Microdrop and Straw Method (Microdrop과 Straw 방법으로 초자화 동결한 소 난자의 생존율에 관한 연구)

  • Yang, B.C.;Yang, B.S.;Sung, H.H.;Im, S.K.;Park, S.B.;Chang, W.K.;Lee, C.K.
    • Journal of Animal Science and Technology
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    • v.44 no.6
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    • pp.701-710
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    • 2002
  • Studies on the Viability of In Vitro-Matured Bovine Oocytes Vitrified by Microdrop and Straw Method To establish vitrification method for bovine oocytes, mature bovine oocytes were vitrified by microdrop (MD) or straw (Straw) method and the viability of vitrified oocytes with or without cumulus cells (CC) were examined by several methods; a) parthenogenetic activation; b) pronuclear formation after in vitro fertilization (IVF); and c) embryonic development after IVF. The survival rate of vitrified oocytes by MD was significantly higher than by Straw (92.50 vs. 74.19%, p<0.05). Most of the oocytes survived from vitrification using the MD methods. Cleavage and blastocyst development of parthenogenetically activated oocytes were higher in MD (45.05% and 10.81%, respectively; p<0.05)) than those in Straw method (27.17% and 6.52%, respectively; p<0.05). Male and female pronuclear formation of vitrified-thawed oocytes with or without cumulus cells (CC) after IVF were examined, respectively. The survival rate of vitrified oocytes by MD without CC was no difference between MD and Straw (80.368.14% vs. 67.31%). Normal fertilization (2PN) rates were not different among groups (Fresh; 54.55% vs. MD; 42.22% vs. Straw; 37.14%, p>0.05). While no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 32.47% vs. MD; 57.78% and Straw 62.86%, p<0.05). The polyspermy (3PN) was appeared in the fresh (12.99%), but no appeared in the vitrified-thawed groups. In the without CC, normal fertilization (2PN) rates were significantly different between fresh and vitrified-thawed oocytes (Fresh; 59.38% vs. MD; 17.31% and Straw; 30.43%, p<0.05). Moreover, no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 23.44% vs. MD; 73.08% and Straw 58.70%, p<0.05). The polyspermy (3PN, >4PN) was appeared not only fresh but vitrified-thawed groups. After IVF, two-cell developmental rates of vitrified oocytes with CC by MD and Straw were significantly low compared to fresh oocytes (Fresh; 81.76% vs. MD; 22.22% and Straw; 11.36%, p<0.05). Blastocyst developmental rates of vitrified oocytes also were significantly low compared to fresh oocytes (Fresh; 28.38 vs. MD; 1.71% and Straw 0%, p<0.05). In the without CC, two-cell developmental rates were no difference between Fresh and MD (27.59% vs. 19.25%, p<0.05), while blastocyst rates were difference between Fresh and MD or Straw (4.31% vs. 0.62% and 0%, respectively; p<0.05). In conclusion, the results indicate that the vitrified bovine oocytes have the ability to develop to the blastocyst stage after IVF.

Prevention of membrane fouling by roughing filter for the stand-alone MD process (해수담수화 막 증류 공정에서 유입수 전처리 적용에 따른 막 오염 평가)

  • Yun, Taekgeun;Jeong, Seongpil;Kim, Hyewon;Hong, Seungkwan;Lee, Seockheon
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.4
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    • pp.301-307
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    • 2018
  • Membrane distillation (MD) is a thermally driven desalination process with a hydrophobic membrane. MD process has been known to have a lower fouling potential compared to other pressure-based membrane desalination process (NF, RO). However, membrane fouling also occurs in MD process. In this study, the membrane fouling was observed in MD process according to the pre-treatment processes. The filtration and precipitation processes were applied as the pre-treatment to prevent the membrane fouling. The pore sizes of roughing filters were 0.4, 5, 10, 30, and $60{\mu}m$. The concentration of the coagulant was 1.2 mg/L as $FeCl_3$. The membrane fouling on MD membrane was successfully removed with both pre-treatment processes.

Approximated Model and Chaining Pattern of Hash Functions (해쉬 함수의 근사적 모델과 연쇄패턴)

  • Lee Sun-Young
    • Journal of Internet Computing and Services
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    • v.7 no.1
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    • pp.39-47
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    • 2006
  • The evaluation of MDx family hash functions such as MD5 is difficult because the design background or a generalized model is unknown. In this paper, an approximated model is proposed to generalize hash functions. The diffusion of a input difference is tested by an approximated model for MD5. The results show that MD5 does not provide perfect diffusion, so MD5 is weak against some attacks. We propose a multiple chaining pattern which provides perfect diffusion in approximated model of hash function without extra calculation or memory. And We show the probability of differential characteristics of our proposal.

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Typology Study about product-selectivity on role of Home-shopping TV MD (홈쇼핑 TV MD의 역할에 따른 제품선택에 관한 유형화 연구)

  • Na, Sang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2535-2542
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    • 2011
  • This study was researched by practical method in a subjectivity study accessible in-depth, in sloughing off old habit of functional quantity analysis about product-selectivity on role of Home-shopping TV MD. The perception pattern come out in this study were divided into four types in Q-methodology. The result is as follows ; it is that divided '1[(N=9) : No-relationship Type], 2[(N=3) : Experience-oriented Type], 3[(N=5) : Ability-focus Type], 4[(N=1) : Drive-importance Type]'. Like this, it found that is very different type all over. In conclusion, this study is to ascertain acceptance behavior about Reception Type on product-selectivity on role of Home-shopping TV MD ; to offer a developmental suggestion about it.

RBF-POD reduced-order modeling of DNA molecules under stretching and bending

  • Lee, Chung-Hao;Chen, Jiun-Shyan
    • Interaction and multiscale mechanics
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    • v.6 no.4
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    • pp.395-409
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    • 2013
  • Molecular dynamics (MD) systems are highly nonlinear and nonlocal, and the conventional model order reduction methods are ineffective for MD systems. The RBF-POD method (Lee and Chen, 2013) employed a radial basis function (RBF) approximated potential energies and inter-atomic forces of MD systems under the framework of the proper orthogonal decomposition (POD) method for the reduced-order modeling of MD systems. In this work, we focus on the numerical procedures of the RBF-POD method and demonstrate how to apply this approach to the modeling of ds-DNA molecules under stretching and bending conditions.

USING MD CAD OBJECTS TO INTEGRATE INFORMATION FOR CONSTRUCTION PROJECTS

  • Chung-Wei Feng ;Yi-Jao Chen
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.515-519
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    • 2005
  • Most information within a construction project roots in drawings and contract documents. Although several methodologies, such as A/E/C and 4D, have employed such a peculiarity to integrate project information, they failed to integrate information in terms of efficiency and consistency. In this research, a MD (Multi-Dimensional) CAD model is developed to improve the process of integrating information for construction projects. This research describes the processes of creating MD CAD objects and embedding information required throughout the project life cycle within MD CAD building components. In addition, a case study is presented to show the efficiency and effectiveness of using MDIIS (Multi-Dimensional Information Integration System) to integrate information for construction projects.

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Virulence-associated plasmids of Salmonella spp. isolated from animals in Korea (동물에서 분리된 Salmonella균의 병원성 관련 Plasmid에 관한 연구)

  • Choi, Won-pil;Jung, Suk-chan
    • Korean Journal of Veterinary Research
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    • v.32 no.3
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    • pp.369-376
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    • 1992
  • This paper dealt with plasmid DNA profile in 98 Salmonella(S) isolated from pigs and cattle sources in Taegu, Gyeongbook and Gyeongnam during the period from 1984 to 1987. Also we were studied for restriction enzyme analysis of the plasmid DNA, and mouse infection, Sereny test and normal setum resistance test in guinea pig for S typhimurium and S enteritidis harbored or cured 60 megadalton(Md) plasmid and 36 Md plasmid, respectively. Of the 13 Salmonella isolated from cattle, 7 Salmonella harbored one or more plasmids and molecular sizes of the large plasmids were 60 Md for S typhimurium and 36 Md for S enteritidis. Of the 85 Salmonella isolated from pigs, 47 Salmonella were confirmed as being one or more plasmids, and all the S typimurium stains harbored 60 Md plasmid. In enzyme digestion with 8 types of restriction endonuclease for 60 Md plasmid DNA of S typhimurium, cleavage patterns were varied to enzymes, and the DNA was segmented into 4 to 15 fragments. In restriction enzyme analysis of 36 Md plasmid DNA obtained from four strains of S. enteritidis, the DNA showed the same cleavage patterns obtained with Eco RI, Hind III and Bam H I, and was segmented into 3 to 5 fragments. In virulence for mice by measuring the 50% lethal dose ($LD_{50}$), the $LD_{50}$ values obtained for 60 Md virulence-associated plasmid harbored strains of S typhimurium and 36 Md virulence-associated plasmid of S enteritidis were up to $10^4$-fold lower than the values obtained for the plasmid-cured strains of the same serotype. Only the plasmid harbored strains were resistant to the bactericidal activity of 90% guinea pig serum, and only they gave positive responses in sereny test. We suggested that their plasmid DNA might be associated with virulence for mice.

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Management of Grapholita molesta and Carposina sasakii Using Mating Disruption in Non-Chemical or Organic Apple Orchards (무농약·유기재배 사과원에서 교미교란제를 이용한 복숭아순나방과 복숭아심식나방의 방제)

  • Lee, Sun-Young;Choi, Kyung-Hee;Do, Yun-Su;Lee, Soon-Won;Yoon, Changmann;Kim, Gil-Hah
    • Korean journal of applied entomology
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    • v.53 no.2
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    • pp.103-110
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    • 2014
  • The efficacy of mating disruptors MD-IKR (Isomate-KR) and MD-CR (Confuser-R) for controlling Grapholita molesta (Busck) and Carposina sasakii (Matsumura) was evaluated in non-chemical or organic apple orchards. For G. molesta, the efficacy of MD-IKR and MD-CR in Chilgok was 99.8 and 99.8% (2011) and 92.4 and 96.7% (2012), respectively, showing different mating reduction values. The efficacy of MD-IKR and MD-CR in Cheongsong was 99.1 and 92.8% (2011) and 99.6 and 99.6% (2012), respectively. For C. sasakii, the efficacy of MD-IKR and MD-CR was 100% at Chilgok and Cheongsong in 2011 and 2012. Evaluation of the shooting and fruit damage rates showed that the efficacy of the mating disruptors in controlling G. molesta and C. sasakii was better than that of the non-control. However, there was no significant control difference between using the mating disruptors and the conventional control. No difference in the efficacy of the two mating disruptors was observed. We believe that MD-IKR could be an alternative to MD-CR.