• Title/Summary/Keyword: agent model

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A Study of Web Application Attack Detection extended ESM Agent (통합보안관리 에이전트를 확장한 웹 어플리케이션 공격 탐지 연구)

  • Kim, Sung-Rak
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.161-168
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    • 2007
  • Web attack uses structural, logical and coding error or web application rather than vulnerability to Web server itself. According to the Open Web Application Security Project (OWASP) published about ten types of the web application vulnerability to show the causes of hacking, the risk of hacking and the severity of damage are well known. The detection ability and response is important to deal with web hacking. Filtering methods like pattern matching and code modification are used for defense but these methods can not detect new types of attacks. Also though the security unit product like IDS or web application firewall can be used, these require a lot of money and efforts to operate and maintain, and security unit product is likely to generate false positive detection. In this research profiling method that attracts the structure of web application and the attributes of input parameters such as types and length is used, and by installing structural database of web application in advance it is possible that the lack of the validation of user input value check and the verification and attack detection is solved through using profiling identifier of database against illegal request. Integral security management system has been used in most institutes. Therefore even if additional unit security product is not applied, attacks against the web application will be able to be detected by showing the model, which the security monitoring log gathering agent of the integral security management system and the function of the detection of web application attack are combined.

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Inhibitory Effect of Cynaroside Isolated from Lonicera japonia Thunb on Doxorubicin-induced Necrosis in Human Renal Proximal Tubular HK-2 Cells (인동덩굴로부터 분리된 Cynaroside이 Doxorubicin으로 유도된 인간 근위세뇨관 HK-2 세포의 괴사에 미치는 저해 효과)

  • Nho, Jong Hyun;Jung, Ho Kyung;Lee, Mu Jin;Jang, Ji Hun;Sim, Mi Ok;Jung, Ja Kyun;Jung, Da Eun;An, Byeong Kwan;Cho, Hyun Woo
    • Korean Journal of Medicinal Crop Science
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    • v.25 no.5
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    • pp.322-327
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    • 2017
  • Background: Cynaroside is a flavone, a flavonoid-like compound, known by different names (luteoloside and cinaroside). It is commonly found in Lonicera japonica Thunb., Chrysanthemum moriflium, and Angelica keiskei. The process of cell death has been classified as necrosis and apoptosis. Necrosis refers to unregulated cell death induced by a chemotherapeutic agent. Doxorubicin is an anthracycline anti-cancer drug used to treat acute leukemia, cancer, and lymphoma. However, it induces nephrotoxicity including tubular damage. Therefore, we investigated the protective effect of cynaroside against doxorubicin-induced necrosis in HK-2 cells. Methods and Results: To confirm the beneficial effect of cynaroside on doxorubicin-induced necrosis, HK-2 cells, a human proximal tubule epithelial cell line were treated with $10{\mu}M$ doxorubicin and $80{\mu}M$ cynaroside. Doxorubicin treatment resulted in increased DNA fragmentation, caspase-3 activity and mitochondria hyperactivation during cell necrosis. However, pretreatment with $80{\mu}M$ cynaroside attenuated DNA fragmentation, caspase-3 activity and mitochondria hyperactivation induced by $10{\mu}M$ doxorubicin in HK-2 cells. Conclusions: These results indicated that pretreatment with cynaroside ameliorated doxorubicin-induced necrosis in HK-2 cells. Therefore, cynaroside be used as a therapeutic agent for improving doxorubicin-induced nephrotoxicity. However, further studies are required to evaluated the toxicity of cynaroside treatment in animals and to determine its protective effect against doxorubicin-induced nephrotoxicity in an animal model.

The Causes of Conflict and the Effect of Control Mechanisms on Conflict Resolution between Manufacturer and Supplier (제조-공급자간 갈등 원인과 거래조정 방식의 갈등관리 효과)

  • Rhee, Jin Hwa
    • Journal of Distribution Research
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    • v.17 no.4
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    • pp.55-80
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    • 2012
  • I. Introduction Developing the relationships between companies is very important issue to ensure a competitive advantage in today's business environment (Bleeke & Ernst 1991; Mohr & Spekman 1994; Powell 1990). Partnerships between companies are based on having same goals, pursuing mutual understanding, and having a professional level of interdependence. By having such a partnerships and cooperative efforts between companies, they will achieve efficiency and effectiveness of their business (Mohr and Spekman, 1994). However, it is difficult to expect these ideal results only in the B2B corporate transaction. According to agency theory which is the well-accepted theory in various fields of business strategy, organization, and marketing, the two independent companies have fundamentally different corporate purposes. Also there is a higher chance of developing opportunism and conflict due to natures of human(organization), such as self-interest, bounded rationality, risk aversion, and environment factor as imbalance of information (Eisenhardt 1989). That is, especially partnerships between principal(or buyer) and agent(or supplier) of companies within supply chain, the business contract itself will not provide competitive advantage. But managing partnership between companies is the key to success. Therefore, managing partnership between manufacturer and supplier, and finding causes of conflict are essential to improve B2B performance. In conclusion, based on prior researches and Agency theory, this study will clarify how business hazards cause conflicts on supply chain and then identify how developed conflicts have been managed by two control mechanisms. II. Research model III. Method In order to validate our research model, this study gathered questionnaires from small and medium sized enterprises(SMEs). In Korea, SMEs mean the firms whose employee is under 300 and capital is under 8 billion won(about 7.2 million dollar). We asked the manufacturer's perception about the relationship with the biggest supplier, and our key informants are denied to a person responsible for buying(ex)CEO, executives, managers of purchasing department, and so on). In detail, we contact by telephone to our initial sample(about 1,200 firms) and introduce our research motivation and send our questionnaires by e-mail, mail, and direct survey. Finally we received 361 data and eliminate 32 inappropriate questionnaires. We use 329 manufactures' data on analysis. The purpose of this study is to identify the anticipant role of business hazard (environmental dynamism, asset specificity) and investigate the moderating effect of control mechanism(formal control, social control) on conflict-performance relationship. To find out moderating effect of control methods, we need to compare the regression weight between low versus. high group(about level of exercised control methods). Therefore we choose the structural equation modeling method that is proper to do multi-group analysis. The data analysis is performed by AMOS 17.0 software, and model fits are good statically (CMIN/DF=1.982, p<.000, CFI=.936, IFI=.937, RMSEA=.056). IV. Result V. Discussion Results show that the higher environmental dynamism and asset specificity(on particular supplier) buyer(manufacturer) has, the more B2B conflict exists. And this conflict affect relationship quality and financial outcomes negatively. In addition, social control and formal control could weaken the negative effect of conflict on relationship quality significantly. However, unlikely to assure conflict resolution effect of control mechanisms on relationship quality, financial outcomes are changed by neither social control nor formal control. We could explain this results with the characteristics of our sample, SMEs(Small and Medium sized Enterprises). Financial outcomes of these SMEs(manufacturer or principal) are affected by their customer(usually major company) more easily than their supplier(or agent). And, in recent few years, most of companies have suffered from financial problems because of global economic recession. It means that it is hard to evaluate the contribution of supplier(agent). Therefore we also support the suggestion of Gladstein(1984), Poppo & Zenger(2002) that relational performance variable can capture the focal outcomes of relationship(exchange) better than financial performance variable. This study has some implications that it tests the sources of conflict and investigates the effect of resolution methods of B2B conflict empirically. And, especially, it finds out the significant moderating effect of formal control which past B2B management studies have ignored in Korea.

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Factors Associated with Failure in The Continuity of Smoking Cessation Among 6 Month's Smoking Cessation Succeses in the Smoking Cessation Clinic of Public Health Center (보건소 금연클리닉 6개월 금연성공자의 금연지속 실패 요인)

  • Choi, Hyeon-Soon;Sohn, Hae-Sook;Kim, Yun-Hee;Lee, Myeong-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.10
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    • pp.4653-4659
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    • 2012
  • This study was performed to investigate the factors related failure in continuity of smoking cessation among persons who were initially successful in quitting smoking for at least 6 months in smoking cessation clinic of public health center. Data were collected with the telephone questionnaire survey and the registered cards from 347 of 6 months quitters from 2006 to 2008 year. Data were analyzed by life table method and Cox-proportional hazard model. In Cox-proportional hazard model, Eup Myeon of residence(HR 2.50, 95% CI 1.69-3.68), without chronic diseases(HR 1.92, 95% CI 1.21-3.04), without another smoker in household(HR 1.93, 95% CI 1.21-3.09) and usage of supplement agent(HR 2.17, 95% CI 1.01-4.68) were independently associated with the failure in continuing to stay smoke-free. The cumulative rate of failure in the continuity of smoking cessation was 28.6% at 6 month and 36.1% at 24 month. For operating a clinic program for smoking cessation, Public health center should makes strategies that a person is continuing smoking cessation for over 6 months after the first 6 momth's smoking cessation.

Effect of 4-hexylresorcinol on Blood Coagulation and Healing of Injured Vessel in a Rat Model

  • Park, Yong-Tae;Park, Si-Yeok;Kim, Min-Keun;Kim, Seong-Gon;Park, Young-Wook;Kwon, Kwang-Jun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.35 no.5
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    • pp.284-293
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    • 2013
  • Purpose: For reconstruction of craniomaxillofacial defects caused by tumor, trauma, infection etc, free flap transplantation with microvascular surgery is a very useful method. Thrombus formation at the anastomosis site is the major cause of graft failure. 4-Hexylresorcinol (4-HR) is generally known as an antiseptic and antiparasitic agent. This study was conducted in order to evaluate the effect of 4-HR on blood coagulation in vitro. In addition, we investigated thrombus formation and endothelial repair of an injured vessel in an animal model. Methods: In the in vitro experiment, we compared blood coagulation time between the 4-HR treated group and normal blood. Thirty rats were used for in vivo animal experiments. After exposure of the right femoral vein, a micro vessel clamp was placed and the femoral vein was intentionally cut. Microvascular anastomosis was performed on all rats using 10-0 nylon under microscopy. The animals were divided into two groups. In the experimental group (n=15), 4-HR (250 mg/kg) mixed with olive oil (10 mL/kg) was administered per os daily. Animals in the control group (n=15) were given olive oil only. The animals were sacrificed at three days, seven days, and fourteen days after surgery and rat femoral vein samples were taken. Vascular patency and thrombus formation were investigated just before sacrifice. Histologic analysis was performed under a microscope. Results: Results of an in vitro blood coagulation test showed that coagulation time was delayed in the 4-HR treated group. The results obtained from an in vivo 4-HR administered rat model showed that the patency of all experimental groups was better at thirty minutes, seven days, and fourteen days after microvascular anastomosis than that of the control group at seven and fourteen days after anastomosis, and the amount of thrombus in the experimental groups was much less than that of the control group. Endothelial repair was observed in the histologic analysis. Conclusion: Findings of this study demonstrated that blood coagulation was delayed in the vitro 4-HR treated group. In addition, good vascular patency, anti-thrombotic effect, and repair of venous endothelial cells were observed in the vivo 4-HR administered rat group.

A Study on B Class Fire Extinguishing Performance of Air Ratio in the Compressed Air Foam System (압축공기포 소화설비의 공기포비에 따른 B급 소화성능 연구)

  • Lee, Jang-Won;Lim, Woo-Sub;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.27 no.6
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    • pp.8-14
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    • 2013
  • This research is to evaluate the fire extinguishing performance at a mixing ratio of pressurized air in the fire extinguishing system of compressed air foam (CAF) which injects compressed air into foam liquid and then discharging. The experimental device is made use of exclusive foam extinguishing facility for compressed air foam that is produces based on Canada National Laboratory and UL 162 standard, apply model of oil fire (B Class) 20 unit in accordance with "Standard of Model Approval and Product Inspection for Fire Extinguishing Agent" to the fire Extinguishing model. Compressed air is injected through the air mixture and study the tendency depending on increasing air foam ratio 1 : 4, 1 : 7, 1 : 10. In addition, the comparison experiments between synthetic surfactants foam and AFFF carry out with it at the air foam ratio 1 : 4. As a result, in the condition of same discharging flow, fire extinguishing effect of AFFF is the fastest at the air foam ratio 1 : 7 and the slowest at 1 : 10. Moreover, the fire extinguishing effect of AFFF in the comparison expeiments between AFFF and synthetic surfactants foam is faster than the other.

Magnitudes of the Harmonic Components Emitted from Utrasonic Contrast Agents in Response to a Diagnostic Utrasound: Theoretical Consideration (진단용 초음파에 의해 가진된 초음파 조영제에서 방사하는 하모닉 성분의 크기: 이론적 고찰)

  • Kang Gwan Suk;Yu Ji Chul;Paeng Dong Guk;Rhim Sung Min;Choi Min Joo
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.2
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    • pp.78-86
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    • 2005
  • This study considers the magnitude of the harmonic components radiated from the ultrasonic contrast agents (UCA) activated by a typical diagnostic ultrasound. The nonlinear dynamic response of UCA to a 2 MHz diagnostic ultrasound pulse was predicted using Gilmore Model. The elastic property of the shell membrane of the UCA was ignored in the numerical model. Simulation was carried out for the UCA varying from 1 - 9 $\mu$m in its initial radius and the driving diagnostic ultrasound whose mechanical index (MI) ranges from 0.125 to 8. The powers of the sub. ultra and second harmonics of the acoustic signal from the UCA activated were compared with that of the fundamental component. The results show that. if the UCA is bigger than its resonant size (2 $\mu$m in radius for the present case) the sub harmonic power was much bigger than the fundamental. In particular, the 2nd harmonic component currently used as an imaging parameter for the harmonic imaging, was predicted to be lower in power than both the sub and the ultra harmonic component. This study indicates that, for obtaining harmonic imaging with UCA, the sub or ultra harmonics could be taken as imaging parameters better than the 2nd harmonic component.

Optimal Payment Contracts in Agent-Owner Relationship (대리인-선주간의 최적보상계약에 관한 연구)

  • 육근효
    • The Journal of Fisheries Business Administration
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    • v.18 no.1
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    • pp.37-57
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    • 1987
  • This article discussed the characteristics of several Pareto-optimal incentive contracts between owner and labor, more specifically, four situations: reporting output jointly observable by labor ana owner; reporting both output and effort; incorporating other endogenous elements (like capital) that affect the production process and Pareto-optimal fee schedules; and ascertaining the effects of private pre-decision information private- decision information, and per-contact informational asymmetries. Also presented were several extensions of the basic contractual model, and the different components of agency costs associated with labor-owner contractual relations. In a single-period model, the agency problem exists because the uncertainty prevents the owner from using the cash flow to determine unambiguously the labor's action. Holmstrom(1979) suggests that "when the same situation repeats itself over time, the effects of uncertainty tend to be reduced and dystunctional behavior is more accurately revealed, thus alleviating the problem of moral hazard. " Under these conditions, if the labor selects the first-best level of effect in each period, the cash flow will be independent and identically distributed over time. As the number of periods increases, the variance of the labows average output, if he selects the first-best level of effort in each period, gets smaller. Note that for this diversification effect to occur, it is necessary that the owner evaluate the labor's effort over the entire history of his employment, rather than evaluate each period's performance separately. Radner(1980) and Rubinstein and Yaari(1980) consider the extreme case in which there are an infinite number of observations. They show that the owner can eventually detect and systematic shirking on the part of the labor by comparing the labor's average output with what would be expected if the labor had been selecting the first-best level of effort in each period. In a dynamic model with incentive problems we have demonstrated that the labor's second-period compensation will depend on his first-period performance. This allows the owner to diversify away some of the uncertainty surrounding the labor's actions. In addition, this allows the owner to smooth the labor's income over time by spreading the risk of the first-period outcome over both periods. At least some unexplored avenves in this area invite future accounting research: situations where owner has different incompatible objectives and negotiates a contract with labor; circumstances in which owner deals with multiple objectives and negotiates contracts with several labors simultaneously; the value of costly accounting information systems and communication in establishing, Pareto-optimal incentive contracts, and the value and effects of inside information, Thorough theoretical or empirical research on each of these topics not only would increase our knowledge about the role and significance of accounting information but could also provide explanations of the inherent differences among various organizations and in their economic behavior. behavior.

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PEP-1-HO-1 prevents MPTP-induced degeneration of dopaminergic neurons in a Parkinson's disease mouse model

  • Youn, Jong Kyu;Kim, Dae Won;Kim, Seung Tae;Park, Sung Yeon;Yeo, Eun Ji;Choi, Yeon Joo;Lee, Hae-Ran;Kim, Duk-Soo;Cho, Sung-Woo;Han, Kyu Hyung;Park, Jinseu;Eum, Won Sik;Hwang, Hyun Sook;Choi, Soo Young
    • BMB Reports
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    • v.47 no.10
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    • pp.569-574
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    • 2014
  • Heme oxygenase-1 (HO-1) degrades heme to carbon dioxide, biliverdin, and $Fe^{2+}$, which play important roles in various biochemical processes. In this study, we examined the protective function of HO-1 against oxidative stress in SH-SY5Y cells and in a Parkinson's disease mouse model. Western blot and fluorescence microscopy analysis demonstrated that PEP-1-HO-1, fused with a PEP-1 peptide can cross the cellular membranes of human neuroblastoma SH-SY5Y cells. In addition, the transduced PEP-1-HO-1 inhibited generation of reactive oxygen species (ROS) and cell death caused by 1-methyl-4-phenylpyridinium ion ($MPP^+$). In contrast, HO-1, which has no ability to transduce into SH-SY5Y cells, failed to reduce $MPP^+$-induced cellular toxicity and ROS production. Furthermore, intraperitoneal injected PEP-1-HO-1 crossed the blood-brain barrier in mouse brains. In a PD mouse model, PEP-1-HO-1 significantly protected against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced toxicity and dopaminergic neuronal death. Therefore, PEP-1-HO-1 could be a useful agent in treating oxidative stress induced ailments including PD.

Effect of silk fibroin peptide derived from silkworm Bombyx mori on the anti-inflammatory effect of Tat-SOD in a mice edema model

  • Kim, Dae-Won;Hwang, Hyun-Sook;Kim, Duk-Soo;Sheen, Seung-Hoon;Heo, Dong-Hwa;Hwang, Gyo-Jun;Kang, Suk-Hyung;Kweon, Hae-Yong;Jo, You-Young;Kang, Seok-Woo;Lee, Kwang-Gill;Park, Kye-Won;Han, Kyu-Hyung;Park, Jin-Seu;Eum, Won-Sik;Cho, Yong-Jun;Choi, Hyun-Chul;Choi, Soo-Young
    • BMB Reports
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    • v.44 no.12
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    • pp.787-792
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    • 2011
  • We investigated whether silk fibroin peptide derived from the silkworm, Bombyx mori, could inhibit inflammation and enhance the anti-inflammatory activity of Tat-superoxide dismutase (Tat-SOD), which was previously reported to effectively penetrate various cells and tissues and exert anti-oxidative activity in a mouse model of inflammation. Inflammation was induced by topical treatment of mouse ears with 12-O-tetradecanoylphorbol-13-acetate (TPA). Histological, Western blot, and reverse transcription-polymerase chain reaction data demonstrated that silk fibroin peptide or Tat-SOD alone could suppress elevated levels of cyclooxygenase-2, interleukin-6, interleukin-1beta, and tumor necrosis factor-alpha induced by TPA. Moreover, silk fibroin peptide significantly enhanced the anti-inflammatory activity of Tat-SOD, although it had no influence on in vitro and in vivo transduction of Tat-SOD. Silk fibroin peptide exhibited anti-inflammatory activity in a mice model of inflammation. Therefore, silk fibroin peptide alone or in combination with Tat-SOD might be used as a therapeutic agent for various inflammatory diseases.