• Title/Summary/Keyword: model control

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Importance of End User's Feedback Seeking Behavior for Faithful Appropriation of Information Systems in Small and Medium Enterprises (중소기업 환경에서의 합목적적 정보시스템 활용을 위한 최종사용자 피드백 탐색행위의 중요성)

  • Shin, Young-Mee;Lee, Joo-Ryang;Lee, Ho-Geun
    • Asia pacific journal of information systems
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    • v.17 no.4
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    • pp.61-95
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    • 2007
  • Small-and-medium sized enterprises(SMEs) represent quite a large proportion of the industry as a whole in terms of the number of enterprises or employees. However researches on information system so far have focused on large companies, probably because SMEs were not so active in introducing information systems as larger enterprises. SMEs are now increasingly bringing in information systems such as ERP(Enterprise Resource Planning Systems) and some of the companies already entered the stage of ongoing use. Accordingly, researches should deal with the use of information systems by SME s operating under different conditions from large companies. This study examined factors and mechanism inducing faithful appropriation of information systems, in particular integrative systems such as ERP, in view of individuals` active feedback-seeking behavior. There are three factors expected to affect end users` feedback-seeking behavior for faithful appropriation of information systems. They are management support, peer IT champ support, and IT staff support. The main focus of the study is on how these factors affect feedback-seeking behavior and whether the feedback-seeking behavior plays the role of mediator for realizing faithful appropriation of information systems by end users. To examine the research model and the hypotheses, this study employed an empirical method based on a field survey. The survey used measurements mostly employed and verified by previous researches, while some of the measurements had gone through minor modifications for the purpose of the study. The survey respondents are individual employees of SMEs that have been using ERP for one year or longer. To prevent common method bias, Task-Technology Fit items used as the control variable were made to be answered by different respondents. In total, 127 pairs of valid questionnaires were collected and used for the analysis. The PLS(Partial Least Squares) approach to structural equation modeling(PLS-Graph v.3.0) was used as our data analysis strategy because of its ability to model both formative and reflective latent constructs under small-and medium-size samples. The analysis shows Reliability, Construct Validity and Discriminant Validity are appropriate. The path analysis results are as follows; first, the more there is peer IT champ support, the more the end user is likely to show feedback-seeking behavior(path-coefficient=0.230, t=2.28, p<0.05). In other words, if colleagues proficient in information system use recognize the importance of their help, pass on what they have found to be an effective way of using the system or correct others' misuse, ordinary end users will be able to seek feedback on the faithfulness of their appropriation of information system without hesitation, because they know the convenience of getting help. Second, management support encourages ordinary end users to seek more feedback(path-coefficient=0.271, t=3.06, p<0.01) by affecting the end users' perceived value of feedback(path-coefficient=0.401, t=6.01, p<0.01). Management support is far more influential than other factors that when the management of an SME well understands the benefit of ERP, promotes its faithful appropriation and pays attention to employees' satisfaction with the system, employees will make deliberate efforts for faithful appropriation of the system. However, the third factor, IT staff support was found not to be conducive to feedback-seeking behavior from end users(path-coefficient=0.174, t=1.83). This is partly attributable to the fundamental reason that there is little support for end users from IT staff in SMEs. Even when IT staff provides support, end users may find it less important than that from coworkers more familiar with the end users' job. Meanwhile, the more end users seek feedback and attempt to find ways of faithful appropriation of information systems, the more likely the users will be able to deploy the system according to the purpose the system was originally meant for(path-coefficient=0.35, t=2.88, p<0.01). Finally, the mediation effect analysis confirmed the mediation effect of feedback-seeking behavior. By confirming the mediation effect of feedback-seeking behavior, this study draws attention to the importance of feedback-seeking behavior that has long been overlooked in research about information system use. This study also explores the factors that promote feedback-seeking behavior which in result could affect end user`s faithful appropriation of information systems. In addition, this study provides insight about which inducements or resources SMEs should offer to promote individual users' feedback-seeking behavior when formal and sufficient support from IT staff or an outside information system provider is hardly expected. As the study results show, under the business environment of SMEs, help from skilled colleagues and the management plays a critical role. Therefore, SMEs should seriously consider how to utilize skilled peer information system users, while the management should pay keen attention to end users and support them to make the most of information systems.

Analysing the effect of impervious cover management techniques on the reduction of runoff and pollutant loads (불투수면 저감기법의 유출량 및 오염부하량 저감 효과 분석)

  • Park, Hyung Seok;Choi, Hwan Gyu;Chung, Se Woong
    • Journal of Environmental Impact Assessment
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    • v.24 no.1
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    • pp.16-34
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    • 2015
  • Impervious covers(IC) are artificial structures, such as driveways, sidewalks, building's roofs, and parking lots, through which water cannot infiltrate into the soil. IC is an environmental concern because the pavement materials seal the soil surface, decreasing rainwater infiltration and natural groundwater recharge, and consequently disturb the hydrological cycle in a watershed. Increase of IC in a watershed can cause more frequent flooding, higher flood peaks, groundwater drawdown, dry river, and decline of water quality and ecosystem health. There has been an increased public interest in the institutional adoption of LID(Low Impact Development) and GI(Green Infrastructure) techniques to address the adverse impact of IC. The objectives of this study were to construct the modeling site for a samll urban watershed with the Storm Water Management Model(SWMM), and to evaluate the effect of various LID techniques on the control of rainfall runoff processes and non-point pollutant load. The model was calibrated and validated using the field data collected during two flood events on July 17 and August 11, 2009, respectively, and applied to a complex area, where is consist of apartments, school, roads, park, etc. The LID techniques applied to the impervious area were decentralized rainwater management measures such as pervious cover and green roof. The results showed that the increase of perviousness land cover through LID applications decreases the runoff volume and pollutants loading during flood events. In particular, applications of pervious pavement for parking lots and sidewalk, green roof, and their combinations reduced the total volume of runoff by 15~61 % and non-point pollutant loads by TSS 22~72 %, BOD 23~71 %, COD 22~71 %, TN 15~79 %, TP 9~64 % in the study site.

Water Balance and Pollutant Load Analyses according to LID Techniques for a Town Development (도시 개발 전·후 LID 기법 적용에 따른 물수지 및 오염부하 변동 특성)

  • Park, Ji-Young;Lim, Hyun-Man;Lee, Hae-In;Yoon, Young-Han;Oh, Hyun-Je;Kim, Weon-Jae
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.11
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    • pp.795-802
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    • 2013
  • According to the increase of impervious area due to the town development, the rate of infiltration generally lessens and that of runoff rises during wet weather events. And it is concerned that its impacts on water quality for the downstream water bodies due to the change of rainfall runoff patterns may also increase. To cope with these issues, LID (Low Impact Development) techniques which try to maintain the characteristics of rainfall runoff regardless of the town development have been introduced actively. However, the behaviors of each LID technique for rainfall runoff and pollutant loads is not understood sufficiently. In this study, considering the applications of some LID techniques, several sets of simulations using a distributed rainfall runoff model, SWMM-LID, have been conducted for D town whose development is progressing. As the results of the simulations, the rates of infiltration/storage have been decreased from 78% in the case before the town development to 15% after the development and increased again by 24% with LID techniques such as porous pavement, rain barrel and rain garden. The rates of runoff have been increased more than three times from 20% in the case before the development to 74% after the development, and they have also been decreased to 66% by the adoption of LID techniques. It has been simulated that porous pavement is more effective than others in the view point of the reduction of runoff and rain barrel is more attractive for the management of pollutant loads (TSS, BOD, COD, T-N and T-P). Therefore, if some LID techniques should be selected for the a new town, it could be concluded that some techniques with better infiltration functions are recommendable for the control of runoff, and ones with larger storage functions for the management of pollutant loads.

Analysis of Wind Vorticity and Divergence in the High-latitude Lower Thermosphere: Dependence on the Interplanetary Magnetic Field (IMF) (고위도 하부 열권 바람의 소용돌이도와 발산 분석: 행성간 자기장(IMF)에 대한 의존도)

  • Kwak, Young-Sil;Lee, Jae-Jin;Ahn, Byung-Ho;Hwang, Jung-A;Kim, Khan-Hyuk;Cho, Kyung-Seok
    • Journal of Astronomy and Space Sciences
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    • v.25 no.4
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    • pp.405-414
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    • 2008
  • To better understand the physical processes that control the high-latitude lower thermospheric dynamics, we analyze the divergence and vorticity of the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions. For this study the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEG CM) is used. The analysis of the large-scale vorticity and divergence provides basic understanding flow configurations to help elucidate the momentum sources that ulti-mately determine the total wind field in the lower polar thermosphere and provides insight into the relative strengths of the different sources of momentum responsible for driving winds. The mean neutral wind pattern in the high-latitude lower thermosphere is dominated by rotational flow, imparted primarily through the ion drag force, rather than by divergent flow, imparted primarily through Joule and solar heating. The difference vorticity, obtained by subtracting values with zero IMF from those with non-zero IMF, in the high-latitude lower thermosphere is much larger than the difference divergence for all IMF conditions, indicating that a larger response of the thermospheric wind system to enhancement in the momentum input generating the rotational motion with elevated IMF than the corresponding energy input generating the divergent motion. the difference vorticity in the high-latitude lower thermosphere depends on the direction of the IMF. The difference vorticity for negative and positive $B_y$ shows positive and negative, respectively, at higher magnetic latitudes than $-70^{\circ}$. For negative $B_z$, the difference vorticities have positive in the dusk sector and negative in the dawn sector. The difference vorticities for positive $B_z$ have opposite sign. Negative IMF $B_z$ has a stronger effect on the vorticity than does positive $B_z$.

The Impact of Changes in Market Shares among Retailing Types on the Price Index (소매업태간 시장점유율 변화가 물가에 미친 영향)

  • Moon, Youn-Hee;Choi, Sung-Ho;Choi, Ji-Ho
    • Journal of Distribution Research
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    • v.17 no.2
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    • pp.93-115
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    • 2012
  • This study empirically examines the impact of changes in market shares among retailing types on the price index. The retailing type is classified into 6 groups: department store, big mart, super market, convenient store, specialty merchant, and on-line store. The market shares of retailing types are calculated by the ratio of each retailing type monthly sales to total monthly retailing sales in which total retailing sales is the sum of each retailing type sales. We employed several price indices: consumer price index (CPI), CPI for living necessaries, and fresh food price index. In addition, this study used fundamental price indices based on 25 product families as well as 42 representative products. The empirical model also included several variables in order to control for the macroeconomic effects and those variables are the exchange rate, M1, an oil price, and the industrial production index. The data is monthly time-series data spanning over the period from January 2000 to December 2010. In order to test for the stability of data series, we conducted ADF test and PP test in which the model and length of lag were determined by the relevant previous literature and based on the AIC. The empirical results indicate that changes in market shares among retailing types have impacts on the price index. Table A shows that impacts differ as to which price index to use and which product families and products to use. For department store, it lowers the price of food and non-alcoholic beverages, home appliances, fresh food, fresh and vegetables, but it keeps the price high for fresh fruit. The big mart retailing type has a positive impact on the price of food, nut has a negative effect on clothing and foot wear, non-food, and fresh fruit. For super market, it has a positive impact on food and non-alcoholic beverages, fresh food, fresh shellfishes, but increases the price of CPI for living necessaries and non-food. The specialty merchant retailing type increases the price level of CPI for living necessaries and fresh fruit. For on-line store type, it keeps the price high for CPI for living necessaries and non-food as well as fresh fruit. For the analysis based on 25 product families shows that changes in market shares among retailing types also have different effects on the price index. Table B summarizes the different results. The 42 representative product level analysis is summerized in Table C and it indicates that changes in market shares among retailing types have different effects on the price index. The study offers the theoretical and practical implication to these findings and also suggests the direction for the further analysis.

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Stabilization and Release Behavior of W1/O/W2-Type Multiple Emulsions Using Various Block Copolymer Emulsifier and Stabilizer (다양한 Block Copolymer를 유화제 및 안정화제로 사용한 W1/O/W2-Type 다중에멀젼의 방출거동 및 안정성)

  • Haw, Jung-Rim;Kim, Cheol-Hun
    • Applied Chemistry for Engineering
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    • v.8 no.4
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    • pp.560-567
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    • 1997
  • A new approach to obtain stable $W_1/O/W_2$ multiple emulsions has been studied ; The basis of the interfacial interaction between a PCL-PEO-PCL triblock copolymer and a lipophilic emulsifier in the dispersed oil phase was examined. $W_1/O/W_2$ multiple emulsions were prepared by the two-step method. Arlacel P-l35 was used as a liphophilic emulsifier and Synperonic PE/F 127 as a hydrophilic one. Eutanol-G was used as an oil phase. NaCl was encapsulated within the multiple emulsion droplets as the internal marker and its release rate studies were carried out. The suability of the multiple emulsions have been assessed by measuring Separation Ratios(%) and microscopic observations. The release of NaCl was significantly reduced in $W_1/O/W_2$ multiple emulsions containing PCL-PEO-PCL triblock copolymer(2k-4k-2k or 6k-4k-6k) in the oil phase. It may be concluded that the copolymer and the emulsifier form effective interfacial complex to enhance stability and to control the release rate. The effective diffusion coefficients of the NaCl were estimated as $2.64{\times}10^{-15}s$and $3.23{\times}10^{-16}gcm^2/s$ for the $W_1/O/W_2$ multiple emulsion containing 1.2 wt % of PCL-PEO-PCL triblock copolymers with compositions of 2k-4k-2k and 6k-4k-2k, respectively. The rate of release decreased with the increase of the initial concentration of NaCl. The results were examined in view of Higuchi mechanism. A kinetic model which is similar to the model for release of dispersed drugs from a polymeric matrix was found to be suitable for the release of NaCl from $W_1/O/W_2$ multiple emulsions.

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A Study on the Legal System in the Inter-Governmental Agreement on the International Space Station (국제우주정거장협정의 법제도에 관한 고찰방안)

  • Kim, Jong-Bok
    • The Korean Journal of Air & Space Law and Policy
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    • v.22 no.1
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    • pp.9-27
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    • 2007
  • The purpose of this paper is to study about the legal system of the Inter-governmental Agreement on the International Space Station('IGA') which was signed on Jan 29,1998. This paper is divided into three main parts ; 1) a review of ISS, 2) the principal rules of IGA, 3) the legal system of IGA. First, the paper draws an outline of ISS by dealing with (1) the definition, characteristics, and functions of ISS, (2) the composition of ISS. Second, the paper explains the principal rules of IGA which include (1) the rule of 'Partnership' and (2) the rule of 'Peaceful Purpose'. Third, the legal system of IGA is studied by looking at five different aspects: (1) the registration system, (2) a general jurisdiction, criminal jurisdiction and a control of jurisdiction, (3) intellectual property rights and other rights beside intellectual property, (4) cross-waiver of liability and several elements in compensation of damages, (5) the dispute resolution. IGA contains new contents and applications of legal system which was not included in the former space law. Therefore IGA will work as a model law for international cooperation of space development. It is important for us to study the matter of ISS, because disputes on the ISS are left solely to contracting parties although IGA will regulate overall situations. The renewed IGA is even more important because all the space development is expected to take place on an international cooperation basis. On the basis of this paper, all the important parts of IGA is expected to be further studied so that the research can contribute to the establishment of the legal system of space development in Korea.

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The Effects of Nuclear Factor-κB Decoy Oligodeoxynucleotide on Lipopolysaccharide-Induced Direct Acute Lung Injury (리포다당질로 인한 직접성 급성폐손상에서 Nuclear Factor-κB Decoy Oligodeoxynucleotide의 효과)

  • Kim, Je Hyeong;Yoon, Dae Wui;Jung, Ki Hwan;Kim, Hye Ok;Ha, Eun Sil;Lee, Kyoung Ju;Hur, Gyu Young;Lee, Sung Yong;Lee, Sang Yeub;Shin, Chol;Shim, Jae Jeong;In, Kwang Ho;Yoo, Se Hwa;Kang, Kyung Ho
    • Tuberculosis and Respiratory Diseases
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    • v.67 no.2
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    • pp.95-104
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    • 2009
  • Background: The pathophysiologic mechanisms of early acute lung injury (ALI) differ according to the type of primary insult. It is important to differentiate between direct and indirect pathophysiologic pathways, and this may influence the approach to treatment strategies. NF-$\kappa$B decoy oligodeoxynucleotide (ODN) is a useful tool for the blockade of the expression of NF-$\kappa$B-dependent proinflammatory mediators and has been reported to be effective in indirect ALI. The purpose of this study was to investigate the effect of NF-$\kappa$B decoy ODN in the lipopolysaccharide (LPS)-induced direct ALI model. Methods: Five-week-old specific pathogen-free male BALB/c mice were used for the experiment. In the preliminary studies, tumor necrosis factor (TNF)-$\alpha$, interleukine (IL)-6 and NF-$\kappa$B activity peaked at 6 hours after LPS administration. Myeloperoxidase (MPO) activity and ALI score were highest at 36 and 48 hours, respectively. Therefore, it was decided to measure each parameter at the time of its highest level. The study mice were randomly divided into three experimental groups: (1) control group which was administered 50 ${\mu}L$ of saline and treated with intratracheal administration of 200 ${\mu}L$ DW containing only hemagglutinating virus of Japan (HVJ) vector (n=24); (2) LPS group in which LPS-induced ALI mice were treated with intratracheal administration of 200 ${\mu}L$ DW containing only HVJ vector (n=24); (3) LPS+ODN group in which LPS-induced ALI mice were treated with intratracheal administration of 200 ${\mu}L$ DW containing 160 ${\mu}g$ of NF-$\kappa$B decoy ODN and HVJ vector (n=24). Each group was subdivided into four experimental subgroups: (1) tissue subgroup for histopathological examination for ALI at 48 hours (n=6); (2) 6-hour bronchoalveolar lavage (BAL) subgroup for measurement of TNF-$\alpha$ and IL-6 in BAL fluid (BALF) (n=6); (3) 36-hour BAL subgroup for MPO activity assays in BALF (n=6); and (4) tissue homogenate subgroup for measurement of NF-$\kappa$B activity in lung tissue homogenates at 6 hours (n=6). Results: NF-$\kappa$B decoy ODN treatment significantly decreased NF-$\kappa$B activity in lung tissues. However, it failed to improve the parameters of LPS-induced direct ALI, including the concentrations of tumor necrosis factor-$\alpha$ and interleukin-6 in BALF, myeloperoxidase activity in BALF and histopathologic changes measured by the ALI score. Conclusion: NF-$\kappa$B decoy ODN, which has been proven to be effective in indirect models, had no effect in the direct ALI model.

The Effects of Sea Cucumber as an Anti-gastritis, Anti-gastric Ulcer, and Anti-Helicobater (해삼의 항위염, 항위궤양 및 항헬리코박터 효과)

  • Oh, Hong-Geun;Moon, Dae-In;Kim, Jung-Hoon;Kang, Young-Rye;Park, Jung-Woo;Seo, Min-Young;Park, Sang-Hoon;Kang, Yang-Gyu;Choe, Chung-Hyeon;Park, In-Sun;Kim, Ju;Yu, Kang-Yeol;Seol, Eu-Ddeum;Kim, Ok-Jin;Lee, Hak-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.5
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    • pp.605-611
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    • 2012
  • Sea cucumber, $Stichopus$ $japonicus$, is used not only as an outstanding tonic food but also as a traditional medicine for the treatment of asthma, hypertension, rheumatism, anemia, and sinus congestion. The purpose of this study was to examine sea cucumber as an anti-gastritis and anti-gastric ulcer in HCl-ethanol-induced gastric and $H.$ $pylori$-infected animal models. Thirty 7-week-old SD rats and Mongolian gerbils were divided into normal (Nor, n=6), control (Con, 60% HCl-ethanol+water, n=6), groupI (DSCI, 60% HCl-ethanol+sea cucumber 30 mg/kg, n=6), groupII (DSCII, 60% HCl-ethanol+sea cucumber 100 mg/kg, n=6), and group III (DSCIII, 60% HCl-ethanol+sea cucumber 300 mg/kg, n=6). Sea cucumber significantly suppressed gastric lesions and ulcers in the 60% HCl-ethanol-induced gastric model. Especially, 100 mg/kg of sea cucumber showed significantly inhibitory effects. In histopathological analysis of the $H.$ $pylori$ model, we found that sea cucumber augmented the eradication rates of $H.$ $pylori$ and attenuated gastric ulcer formation. Our results suggest that sea cucumber has inhibitory effects on gastritis and gastric ulcers. In addition, sea cucumber can be applied for the treatment of $H.$ $pylori$.

Effects of Herbal Complex on Blood Glucose in Streptozotocin-induced Diabetic Rats and in Mice Model of Metabolic Syndrome (생약복합제의 Streptozotocin 유발 당뇨 및 대사성증후군 모델 동물에서의 혈당에 미치는 효과)

  • Park, Han-Seok;Lee, Yeon-Sil;Choi, Se-Jin;Kim, Jin-Kyu;Lee, Yun-Lyul;Kim, Hyun-Gwen;Koo, Sam-Hoi;Ku, Dae-Hoy;Ki, Seung-Il;Lim, Soon-Sung
    • Korean Journal of Pharmacognosy
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    • v.40 no.3
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    • pp.196-204
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    • 2009
  • This study was carried out to investigate the in vivo and in vitro inhibitory effect of a traditional herbal complex (HC) extract prepared from a mixture of four oriental herbs (Dioscorea Rhizoma, Glycine soja Sieb. et Zucc, Bombycis corpus, Fermented Glycine soja) that have been widely used for the treatment and prevention of diabetes mellitus on hyperglycemia. The water extract of HC showed potent inhibitory effect on $\alpha$-glucosidase with $IC_{50}$ value of 1.24 mg/mL. Additionally, the ethanol extract of HC was also found to exhibit significant inhibitory effect against protein tyrosine phosphatase $1{\beta}$ ($PTP1{\beta}$), which is known as a major regulator of both insulin and leptin signaling. In the $PTP1{\beta}$ inhibitory assay, the most active n-hexane fraction obtained from the ethanol extract of HC, was identified as a mixture of fatty acid derivatives by gas chromatography-mass spectrometry (GC-MS). In high-fat diet-low dose streptozotocin (STZ)-induced diabetic rat, the water extract of HC improved the oral glucose intolerance as compared with rosiglitazone. HC also caused a marked decrease of body weight and fasting blood glucose and a significant improvement on glucose tolerance in metabolic syndrome mice model. These findings support that this traditional HC may be useful in the control of blood glucose in diabetes mellitus and metabolic syndrome.