• Korea-Australia Rheology Journal
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• v.18 no.2
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• pp.67-81
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• 2006

Using a strain-controlled rheometer, the dynamic viscoelastic properties of aqueous xanthan gum solutions with different concentrations were measured over a wide range of strain amplitudes and then the linear viscoelastic behavior in small amplitude oscillatory shear flow fields was investigated over a broad range of angular frequencies. In this article, both the strain amplitude and concentration dependencies of dynamic viscoelastic behavior were reported at full length from the experimental data obtained from strain-sweep tests. In addition, the linear viscoelastic behavior was explained in detail and the effects of angular frequency and concentration on this behavior were discussed using the well-known power-law type equations. Finally, a fractional derivative model originally developed by Ma and Barbosa-Canovas (1996) was employed to make a quantitative description of a linear viscoelastic behavior and then the applicability of this model was examined with a brief comment on its limitations. Main findings obtained from this study can be summarized as follows: (1) At strain amplitude range larger than 10%, the storage modulus shows a nonlinear strain-thinning behavior, indicating a decrease in storage modulus as an increase in strain amplitude. (2) At strain amplitude range larger than 80%, the loss modulus exhibits an exceptional nonlinear strain-overshoot behavior, indicating that the loss modulus is first increased up to a certain strain amplitude(${\gamma}_0{\approx}150%$) beyond which followed by a decrease in loss modulus with an increase in strain amplitude. (3) At sufficiently large strain amplitude range (${\gamma}_0>200%$), a viscous behavior becomes superior to an elastic behavior. (4) An ability to flow without fracture at large strain amplitudes is one of the most important differences between typical strong gel systems and concentrated xanthan gum solutions. (5) The linear viscoelastic behavior of concentrated xanthan gum solutions is dominated by an elastic nature rather than a viscous nature and a gel-like structure is present in these systems. (6) As the polymer concentration is increased, xanthan gum solutions become more elastic and can be characterized by a slower relaxation mechanism. (7) Concentrated xanthan gum solutions do not form a chemically cross-linked stable (strong) gel but exhibit a weak gel-like behavior. (8) A fractional derivative model may be an attractive means for predicting a linear viscoelastic behavior of concentrated xanthan gum solutions but classified as a semi-empirical relationship because there exists no real physical meaning for the model parameters.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.61-71
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• 2000

By screening a cDNA library of auxin-treated mung bean (Vigna radiata L.) hypocotyls, we have isolated two full-length cDNA clones, pVR-ACS6 and pVR-ACS7, for 1-aminocyclopropane-1-carboxylate (ACC) synthase, the rate-limiting enzyme in the ethylene biosynthetic pathway. While PVR-ACS6 corresponds to the previously identified PCR fragment pMBA1, pVR-ACS7 is a new cDNA clone. A comparison of deduced amino acid sequences among auxin-induced ACC synthases reveal that these enzymes share a high degree of homology (65-75%) to VR-ACS6 and VR-ACS7 polypeptides, but only about 50% to VR-ACS1 polypeptide. ACS6 and ACS7 are specifically induced by auxin, while ACS1 is induced by cycloheximide, and to lesser extent by excision and auxin treatment. Results from nuclear run-on transcription assay and RNA gel blot studies revealed that all three genes were transcriptionally active displaying unique patterns of induction by IAA and various hormones in etiolated hypocotyls. Particularly, 24-epibrassinolide (BR), an active brassinosteroid, specifically enhanced the expression of VR-ACS7 by distinct temporal induction mechanism compared to that of IAA. In addition, BR synergistically increased the IAA-induced VR-ACS6 and VR-ACS7 transcript levels, while it effectively abolished both the IAA- and kinetin-induced accumulation of VR-ACS1 mRNA. In light-grown plants, VR-ACS1 was induced by IAA in roots, whereas W-ACS6 in epicotyls. IAA- and BR-treatments were not able to increase the VR-ACS7 transcript in the light-grown tissues. These results indicate that the expression of ACC synthase multigene family is regulated by complex hormonal and developmental networks in a gene- and tissue-specific manner in mung bean plants. The VR-ACS7 gene was isolated, and chimeric fusion between the 2.4 kb 5'-upstream region and the $\beta$-glucuronidase (GUS) reporter gene was constructed and introduced into Nicotiana tobacum. Analysis of transgenic tobacco plants revealed the VR-ACS7 promoter-driven GUS activity at a highly localized region of the hypocotyl-root junction of control seedlings, while a marked induction of GUS activity was detected only in the hypocotyl region of the IAA-treated transgenic seedlings where rapid cell elongation occurs. Although there was a modest synergistic effect of BR on the IAA-induced GUS activity, BR alone failed to increase the GUS activity, suggesting that induction of VR-ACS7 occurs via separate signaling pathways in response to IAA and BR.

• Journal of Veterinary Clinics
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• v.30 no.1
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• pp.57-60
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• 2013

Ingestion of grapes or raisins has been reported to the occurrence of acute renal failure (ARF) in dogs, although the mechanism remains undetermined. The prognosis often depends on the severity or clinical course of the disease at the time of presentation and is poor if the dog becomes anuric phase. To explore the characteristics and outcome of ARF caused by grape or raisin poisoning, sequentially collected data, from 2005 to 2008, of the Veterinary Medical Teaching Hospital at the Kangwon National University for clinical evaluation were retrospectively analyzed. Of the 11 clinically affected dogs, 4 cases made a full recovery, 3 died and 4 were euthanized. All but one case (raisin ingestion) had a history of grape exposure, but the exact quantity of fruit ingested was not known. The female dogs accounted for 72.7% (8 cases). Overall, the mean age was 5.3 years (range 0.2-11.3 years), and the mean body weight was 4.1 kg (range 1.4-13 kg). The average duration of hospital stay was 7.1 days (range 2-22 days). Vomiting and anorexia was reported in all dogs. Diarrhea (4 cases), oliguria (5 cases), and anuria (4 cases) with or without isosthenuria were also reported. Five dogs of 11 had mild to moderate anemia, with a decrease in packed cell volume and hemoglobin. All dogs had elevations in serum phosphorous, creatinine, and blood urea nitrogen values, but calcium values were variable; 2 dogs with hypocalcemia, 2 dogs with hypercalcemia, and the remaining 7 cases within reference interval. Dogs (n = 8) with measured on blood gas parameters had metabolic acidosis. In addition, higher serum enzyme activities were observed; amylase in 8 (72.7%) dogs, alkaline phosphatase in 7 (63.6%) dogs, and alanine aminotransferase in 5 (45.5%) dogs. Non-survived dogs revealed lower counts of platelet and lymphocyte subpopulation, as compared to the survived dogs.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.229-238
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• 2007

Sensor networks consist of many tiny sensor nodes that collaborate among themselves to collect, process, analyze, and disseminate data. In sensor networks, sensor nodes are typically powered by batteries, and have limited computing resources. Moreover, the redeployment of nodes by energy exhaustion or their movement makes network topology change dynamically. These features incur problems that do not appear in traditional, wired networks. Security in sensor networks is challenging problem due to the nature of wireless communication and the lack of resources. Several efforts are underway to provide security services in sensor networks, but most of them are preventive approaches based on cryptography. However, sensor nodes are extremely vulnerable to capture or key compromise. To ensure the security of the network, it is critical to develop suity mechanisms that can survive malicious attacks from "insiders" who have access to the keying materials or the full control of some nodes. In order to protect against insider attacks, it is necessary to understand how an insider can attack a sensor network. Several attacks have been discussed in the literature. However, insider attacks in general have not been thoroughly studied and verified. In this paper, we study the insider attacks against routing protocols in sensor networks using the Ad-hoc On-Demand Distance Vector (AODV) protocol. We identify the goals of attack, and then study how to achieve these goals by modifying of the routing messages. Finally, with the simulation we study how an attacker affects the sensor networks. After we understand the features of inside attacker, we propose a detect mechanism using hop count information.

• Journal of Nutrition and Health
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• v.19 no.6
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• pp.363-373
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• 1986

This study was devised to elucidate whether soused shrimp exhibits a digestive action on boiled pork meats. and the mechanism by which sousing with a high concentration of sodium chloride preserves nutrients in foods for a prolonged pe\ulcornerriod. Protease was isolated from soused shrimp using a combination of ammonium sulfate fractionation. DEAE - cellulose ion exchange chromatography and gel filtra\ulcornertion. The isolated protease had specific activity of 1.560 units. 210 purification fo\ulcornerld with an yield of 38%. Its optimum pH and temperature were 8.0 and $43^{\circ}C$ respectively. The molecular weight of the enzyme was 35.000. The Km value of the enzyme for casein was 1.6 x $10^{-6}$ M The e=yme required the presence of cu\ulcornerpric ion to exhibit its full activity. Eighty eight percent of the enzyme activity was in\ulcornerhibited by 3.5M NaCI showing a reversibly linear decrease of the enzyme activity as NaCI concentration increased. The nature of the inhibition by NaCl was rever\ulcornersible and noncompetitive. The protease activity in soused shrimp was well preser\ulcornerved with the elapse of time at least in part due to NaCI induced suppression of autodigestion. The enzyme was denatured by acid easily. i.e. 1% of the original activity remained after staying at pH 2 for 10 minutes. which is within the norm\ulcorneral range of pH of the human stomach. Soused shrimp was observed to be one of those containing the highest protease activity compared with the other soused foo\ulcornerds such as soused oyster. squid. clam. and Pollack intestine with respect to spec\ulcornerific activities of dialized 1:4 whole homogenates(w/v) in 5 mM sodium phospha\ulcornerte - 2.4 mM j3 - mercaptoethanol buffer. pH 8.0. Casein and boiled meats including pork, beef, and chicken appeared to be the good substrates for the protease. Casein was the best. Therefore. the ingestion of boiled meats including pork together with soused sh\ulcornerrimp would help digestion of boiled pork in human not only by increasing appe\ulcornertite also by the direct proteolytic digestion of boiled meats by soused shrimp to\ulcorner some extent. And a high concentration of sodium chloride inhibited the protease activity reversibly in a remarkable degree, which ensued in a significant retardat\ulcornerion of autodigestion of protein in foods by proteases, and hereby contributed to the preservation of foods for an extended period.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.364-372
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• 2000

Subcategorization, defining dependency relation between predicates and their complements, is an important source of knowledge for resolving syntactic and semantic ambiguities arising in analyzing sentences. This paper describes a Korean subcategorization dictionary, particularly annotated with semantic roles of complements coupled with thesaural semantic hierarchy as well as syntactic dependencies. For annotating roles, we defined 25 semantic roles associated with surface case markers that can be used to derive semantic structures directly from syntactic ones. In addition, we used more than 120,000 entries of thesaurus to specify concept markers of noun complements, and also used 47 and 17 predicate patterns for verbs and adjectives, respectively, to express dependency relation between predicates and their complements. Using a full-fledged thesaurus for specifying concept markers makes it possible to build an effective selectional restriction mechanism coupled with the subcategorization dictionary, and using the standard predicate patterns for specifying dependency relations makes it possible to avoid inconsistency in the results and to reduce the costs for constructing the dictionary. On the bases of these, we built a Korean subcategorization dictionary for frequently used 13,000 predicates found in corpora with the aid of a tool specially designed to support this task. An experimental result shows that this dictionary can provide 72.7% of predicates in corpora with appropriate subcategorization information.

• Journal of Distribution Science
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• v.16 no.5
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• pp.71-81
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• 2018

Purpose - Our research aims to investigate the mediating effect of employee creativity on the relationship between intrinsic motivation and job performance using relationship using Chinese department salespeople samples. Another objective of this study is to be clear boundary conditions that strengthen or weaken the effects of intrinsic motivation on work outcomes (i.e., employee creativity and job performance). Drawing on JD-R theory, we suggest that the two types of coworker support play differential moderating roles in the intrinsic motivation, employee creativity relationship by increasing or decreasing job resources and demands in different ways. Research design, data, and methodology - This empirical study data were collected from gathered from a sample of full time salespeople in China. A total of 550 questionnaires were distributed and 300 responses were collected, indicating a response rate of 84.0%. Working with a sample of 300 salespeople working in a department store in China. SPSS 18.0, Process 2.16 Macro, and M-Plus 8.0 software were used in the data analysis. Descriptive statistics were used to evaluate the distribution of the employee profiles and correlations between variables. M-Plus 8.0 software was used to test the model fit, validity and reliability of the variables. Finally, all research hypotheses was estimated by SPSS Macro 2.16. Results - To test our research hypotheses, we employed an analytical strategy suggested by Hayes (2013; 2015) and Shrout and Bolger (2002). In this study, we tested the relationship between intrinsic motivation and job performance throughout employee creativity. Results showed intrinsic motivation and job performance was partially mediated by employee creativity. The positive relationship between intrinsic motivation and employee creativity when coworker emotional support was high than when it was low. In contrast, the positive association between intrinsic motivation and employee creativity was stronger when coworker instrumental support was low than when it was high. Coworker emotional and instrumental support further moderated the indirect effect of intrinsic motivation on job performance through employee creativity. Conclusions - This study extends the conceptual model and empirical researches in coworker supports literature by representing a fundamental mechanism of how salespeople's intrinsic motivation and job performance throughout employee creativity.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.485-495
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• 2000

The parallel computer system that uses parallel program on the application such as a large scale business or complex operation is required. One of crucial operation of parallel computer system is synchronization. A representative method of synchronization is barrier synchronization. A barrier forces all process to wait until all the process reach the barrier and then releases all of the processes. There are software schemes, hardware scheme, or combinations of these mechanism to achieve barrier synchronization which tends to use hardware scheme. Besides, barrier synchronization lets parallel computer system fast because it has fewer start-up overhead. In this paper, we propose a new switch module that can implement fast and fault-tolerant barrier synchronization in hardware scheme. A proposed barrier synchronization is operated not in full-switch-driven method but in processor-driven method. An effective barrier synchronization is executed with inexpensive hardware supports. Therefore, a new proposed hardware barrier synchronization is designed that it is operated in arbitrary network topology. In this paper, we only show comparison of barrier synchronization on Multistage Interconnection Network. This research results in 24.6-24.8% reduced average delay. Through this result, we can expect lower average delay in irregular network.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.311-317
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• 2006

Using PCR amplification, we cloned a cellulase gene (ce/H) from the Bacillus subtilis AH18 which has plant growth-promoting activity and antagonistic ability against pepper blight caused by Phytophthora capsici. The 1.6 kb PCR fragment contained the full sequence of the cellulase gene and the 1,582 bp gene deduced a 508 amino acid sequence. Similarity search in protein database revealed that the cellulase of B. subtilis AH18 was more than 98% homologous in the amino acid sequence to those of several major Bacillus spp. The ce/H was expressed in E. coli under an IPTG inducible lac promoter on the vector, had apparent molecular weight of about 55 kDa upon CMC-SDS-PAGE analysis. Partially purified cellulase had not only cellulolytic activity toward carboxymethyl-cellulose (CMC) but also insoluble cellulose, such as Avicel and filter paper (Whatman No. 1). In addition, the cellulase could degrade a fungal cell wall of Phytophthora capsici. The optimum pH and temperature of the ce/H coded cellulase were determined to be pH 5.0 and $50^{\circ}C$. The enzyme activity was activated by $AgNO_3$ or $CoCl_2$. However its activity was Inhibited by $HgC1_2$. The enzyme activity was activated by hydroxy urea or sodium azide and inhibited by CDTA or EDTA. The results indicate that the cellulase gene, ce/H is an antifungal mechanism of B. subtilis AH18 against phytophthora blight disease in red-pepper.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.855-862
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• 2012

Caenorhabditis elegans, a free-living nematode mainly found in the soil pore water, roles the critical function in trophic levels, energy flow, and decomposition in soil ecosystem. C. elegans is commonly used species to test soil toxicity. Recently, they are employed broadly as a test organism in nanotoxicology. In this study, a review of the toxicity of nanomaterials for C. elegans was presented based on SCI (E) papers. The nanotoxicity studies using C. elegans have been reported in 20 instances including the mechanism of toxicity. Most studies used K-medium, S-medium, and NGM (Nematode Growth Medium) plate as an exposure medium to test toxicity of nanoparticles. The effects observed include anti aging, phototoxicity, genotoxicity, and dermal effects on C. elegans exposed to nanoparticles. We found that the toxic mechanisms were related with various aspects such as lifespan abnormality, oxidative stress, distribution of particles on inter-organisms, and stress-related gene analysis. C. elegans has advantage to test toxicity of nanoparticles due to various cellular activities, full genome information, and easy observation of transparent body. C. elegans was considered to be a good test species to evaluate the nanotoxicity.