• 약학회지
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• 제38권4호
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• pp.372-378
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• 1994

Choleretic effect and absorption of ursodeoxycholic acid (UDCA) in rats were studied using UDCA alone and it's ${\beta}-cyclodextrin$ $({\beta}-CyD)$ inclusin complex (UDCA-IC). In spite of increase in solubility and dissolution rate, absorption of UDCA-IC was decreased compared with UDCA alone. Choleretic effect of UDCA-IC was also decreased. It looks that UDCA forms stronger inclusion complex with ${\beta}-CyD$ than any other drug or organic biological material. From this study, it was suggested that UDCA might be used as a new potential competing agent when inclusion complexes of drugs with ${\beta}-CyD$ were administered for the improvement of poor bioavailability.

• 한국경영과학회지
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• 제37권1호
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• pp.19-28
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• 2012

We consider a multi-agent scheduling problem such that each agent tries to maximize the weighted number of just-in-time jobs. Two objectives are considered : the first is to find the optimal solution for one agent with constraints on the other agents' weight functions, and the second is to find the largest set of efficient schedules of which corresponding objective vectors are different for the case with identical weights. We show that when the number of agents is fixed, the single machine case with the first objective is NP-hard in the ordinary sense, and present the polynomial- time algorithm for the two-machine flow shop case with the second objective and identical weights.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.297-304
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• 2021

In a duopoly situation, one firm can gain competitive advantage by attracting the price-sensitive customers from its competitor leading to higher profits through higher sale revenue for the competing company. A simulation study in which there are two electric car manufacturers with agent based modelling was conducted in order to verify this contention. The first step consisted of defining the baseline. Simulations of 1000 times and agent-based modelling were conducted with the assumption that company 1 reduced its price to the maximum of 20% thereby contributing to the switch-over of a maximum of 40% of the price sensitive customers of company 2. The results of 1000 simulations and agent-based modelling highlighted that price reduction by company 1 resulted in a significant increase in the number of customers, presumably due to switch-over from company 2 and there was a corresponding increase in revenues from both of the sales avenues. Thus, Company 1 achieved competitive advantage by marketing its cars to the customers of Company 2 using price reduction strategy to attract them. This study has ramifications for companies that aim to sway the price sensitive customers from a competitor.

• 통상정보연구
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• 제7권4호
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• pp.117-134
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• 2005

B2B transaction was expected to dominate in the global market and thus many e-marketplaces have been built since 1999 in Korea. However, only a few e-marketplaces are thriving and the future of B2B e-marketplaces except MRO area seem to be uncertain. This paper explores why B2B transactions only in MRO area are rapidly increasing and examines the competing structure and business models of MRO e-marketplace. Business models of MRO e-marketplaces are various among different countries. However, they can be classified as three business models:information portal model, purchasing agent model, open market model. It is not easy to answer which business model is most competitive because each models have their own advantages and functions. Information portal model can be easily applied for the e-marketplace which operates off-line enterprises. Purchasing agent model is favorable to the e-marketplaces which has already obtained buyers and sellers. Open market model is desirable to the e-marketplace which has excess to global market.

• 한국시뮬레이션학회논문지
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• 제20권2호
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• pp.29-40
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• 2011

본 연구에서는 에이전트 모형 기반 시뮬레이션 기법을 이용하여 국내 중형 고급승용차 제품시장에서 경쟁 제품들의 확산 다이나믹스를 예측하기 위한 환경조건을 도출하고자 민감도 분석을 실시하였다. 본 연구에서는 소비자의 구매 특성과 행동을 모방한 소비자 에이전트 모형을 이용하며 사회적 네트워크로 연결된 소비자 에이전트들의 집단은 하나의 가상시장을 이룬다. 제품을 구매한 소비자 에이전트가 이웃 에이전트들에게 제품정보를 전달함으로써 실제 시장처럼 구전현상이 나타나고 이는 잠재적 소비자 에이전트들의 제품선택에 영향을 주게 되어 확산 다이나믹스 패턴이 변화하게 된다. 가상시장의 확산 다이나믹스가 실제 시장의 확산다이나믹스를 반영하기 위해서는 초기채택자 비율, 사회적 네트워크의 구조, 소비자 에이전트의 구매시점 결정방법 등의 가상시장 환경설정이 중요하다. 그러나 이러한 환경조건들은 실제시장에서 측정하기가 어렵기 때문에 본 연구에서는 다양한 환경조건하에서의 확산다이나믹스패턴을 실제 데이터와 비교 분석하여 적합한 환경조건을 찾고자 한다.

• 한국시뮬레이션학회논문지
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• 제14권1호
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• pp.9-18
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• 2005

Attempts to attack hosts in the network have become diverse, due to crackers developments of new creative attacking methods. Under these circumstances the role of intrusion detection system as a security system component gets considerably importance. Therefore, in this paper, we have suggested multiple intrusion detection system based on the contract net protocol which provides the communication among multiple agents. In this architecture, fuzzy rule based system has been applied for agent selection among agents competing for being activated. The simulation models are designed and implemented based on DEVS formalism which is theoretically well grounded means of expressing discrete event simulation models.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.187.2-187.2
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• 2003

The cyclin-dependent kinases (CDKs), a group of serine/threonine kinases that form active heterodimeric complexes binding to cyclins, are key regulators of the cell cycle. The role of cyclin dependent kinases(CDKs) in cell cycle regulation has stimulated an interest in them as potential targets for proliferative diseases such as cancer, psoriasis, and chemotherapeutic agent-induced alopecia. Indirubin, an active ingredient of a traditional Chinese recipe Danggui Longhui Wan, are potent CDK inhibitors competing with ATP for binding to the catalytic site of the CDKs. (omitted)

• Mycobiology
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• 제42권2호
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• pp.152-157
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• 2014

The iron uptake and utilization pathways play a critical role in allowing human pathogens, including Cryptococcus neoformans, the causative agent of fatal meningoencephalitis, to survive within the mammalian body by competing with the host for iron. Here we show that the iron regulon is also required for diverse environmental stress responses and that in C. neoformans, it is regulated by the high-osmolarity glycerol response (HOG) pathway. Between CFO1 and CFO2, two ferroxidase genes in the iron regulon, CFO1 but not CFO2 was induced during oxidative and osmotic stress. Interestingly, we found that the HOG pathway repressed basal expression of both CFO1 and CFO2. Furthermore, when the HOG pathway was blocked, CFO2 also responded to oxidative and osmotic stress and the response of CFO1 was increased. We also established that CFO1 plays a major role in responding and adapting to diverse environmental stresses, including oxidative and genotoxic damage, osmotic fluctuations, heavy metal stress, and stress induced by cell membrane destabilizers. Therefore, our findings indicate that in C. neoformans, the iron uptake and utilization pathways are not only required for iron acquisition and survival, but also play a significant role in the environmental stress response through crosstalk with the HOG pathway.

• BMB Reports
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• 제47권12호
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• pp.691-696
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• 2014

${\alpha}$-Enolase is a glycolytic enzyme and a surface receptor for plasminogen. ${\alpha}$-Enolase-bound plasminogen promotes tumor cell invasion and cancer metastasis by activating plasmin and consequently degrading the extracellular matrix degradation. Therefore, ${\alpha}$-enolase and plasminogen are novel targets for cancer therapy. We found that the amino acid sequence of a peptide purified from enzymatic hydrolysates of seahorse has striking similarities to that of ${\alpha}$-enolase. In this study, we report that this peptide competes with cellular ${\alpha}$-enolase for plasminogen binding and suppresses urokinase plasminogen activator (uPA)-mediated activation of plasminogen, which results in decreased invasive migration of HT1080 fibrosarcoma cells. In addition, the peptide treatment decreased the expression levels of uPA compared to that of untreated controls. These results provide new insight into the mechanism by which the seahorse-derived peptide suppresses invasive properties of human cancer cells. Our findings suggest that this peptide could emerge as a potential therapeutic agent for cancer.

• 한국물환경학회지
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• 제22권6호
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• pp.991-995
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• 2006

The layered double hydroxide with the insertion of chloride ions (LDH-Cl), which was synthesized by the co-precipitation method, was applied to investigate the fundamental aspects of the absorptive agent for phosphate removal from wastewater. The adsorption capacity was best described by the Langmuir-FreundIich isotherm, and the estimated isotherm parameters indicate that the LDH-CI capacity for the phosphate removal is much higher than that observed using a natural adsorbent material such iron oxide tailing. The kinetic experiment also showed that the LDH-Cl adsorption reaction rapidly at the adsorptive rate of 0.55 mg-P/g-LDH/min, implying that this adsorbent can be of use in the full-scale applications. The pH had a minimal effect on the LDH adsorption capacity in the range of 5 to 11, although the capacity dropped at the low pHs because of the change in LDH surface properties. Furthermore, other anions such as $Cl^-$ and $NO_3{^-}$ commonly found in the wastewater streams insignificantly affected the phosphate removal efficiencies, while $HCO_3{^-}$ ions had a negative effect on the LDH adsorption capacity due to its high selectivity. The phosphate removal experiment using the actual secondary effluent from a wastewater treatment plant showed the similar decrease in adsorption capacity, indicating that the bicarbonate ions in the wastewater were competing with phosphate for the adsorptive site in the surface of the LDH-Cl. Overall, the synthetic adsorbent material, LDH-Cl, can be a feasible alternative over other conventional chemical agents, since the LDH-Cl exhibits the high phosphate removal capacity with the low sensitivity to other environmental conditions.