• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.996-1004
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• 2020

Various genetically engineered microorganisms have been developed for the removal of heavy metal contaminants. Metal biosorption by whole-cell biosorbents can be enhanced by overproduction of metal-binding proteins/peptides in the cytoplasm or on the cell surface. However, few studies have compared the biosorption capacity of whole cells expressing intracellular or surface-displayed metal-adsorbing proteins. In this study, several constructs were prepared for expressing intracellular and surface-displayed Ochrobactrum tritici 5bvl1 ChrB in Escherichia coli BL21(DE3) cells. E. coli cells expressing surface-displayed ChrB removed more Cr(VI) from aqueous solutions than cells with cytoplasmic ChrB under the same conditions. However, intracellular ChrB was less susceptible to variation in extracellular conditions (pH and ionic strength), and more effectively removed Cr(VI) from industrial wastewater than the surface-displayed ChrB at low pH (<3). An adsorption-desorption experiment demonstrated that compared with intracellular accumulation, cell-surface adsorption is reversible, which allows easy desorption of the adsorbed metal ions and regeneration of the bioadsorbent. In addition, an intrinsic ChrB protein fluorescence assay suggested that pH and salinity may influence the Cr(VI) adsorption capacity of ChrB-expressing E. coli cells by modulating the ChrB protein conformation. Although the characteristics of ChrB may not be universal for all metal-binding proteins, our study provides new insights into different engineering strategies for whole-cell biosorbents for removing heavy metals from industrial effluents.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.41-72
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• 2008

The purpose of this study is the investigation of the effects of user participation, network effect, social influence, and usefulness on stickiness and continued use on Internet communities. In this research, stickiness refers to repeat visit and visit duration to an Internet community. Continued use means the willingness to continue to use an Internet community in the future. Internet community-based companies can earn money through selling the digital contents such as game, music, and avatar, advertizing on internet site, or offering an affiliate marketing. For such money making, stickiness and continued use of Internet users is much more important than the number of Internet users. We tried to answer following three questions. Fist, what is the effects of user participation on stickiness and continued use on Internet communities? Second, by what is user participation formed? Third, are network effect, social influence, and usefulness that was significant at prior research about technology acceptance model(TAM) still significant on internet communities? In this study, user participation, network effect, social influence, and usefulness are independent variables, stickiness is mediating variable, and continued use is dependent variable. Among independent variables, we are focused on user participation. User participation means that Internet user participates in the development of Internet community site (called mini-hompy or blog in Korea). User participation was studied from 1970 to 1997 at the research area of information system. But since 1997 when Internet started to spread to the public, user participation has hardly been studied. Given the importance of user participation at the success of Internet-based companies, it is very meaningful to study the research topic of user participation. To test the proposed model, we used a data set generated from the survey. The survey instrument was designed on the basis of a comprehensive literature review and interviews of experts, and was refined through several rounds of pretests, revisions, and pilot tests. The respondents of survey were the undergraduates and the graduate students who mainly used Internet communities. Data analysis was conducted using 217 respondents(response rate, 97.7 percent). We used structural equation modeling(SEM) implemented in partial least square(PLS). We chose PLS for two reason. First, our model has formative constructs. PLS uses components-based algorithm and can estimated formative constructs. Second, PLS is more appropriate when the research model is in an early stage of development. A review of the literature suggests that empirical tests of user participation is still sparse. The test of model was executed in the order of three research questions. First user participation had the direct effects on stickiness(${\beta}$=0.150, p<0.01) and continued use (${\beta}$=0.119, p<0.05). And user participation, as a partial mediation model, had a indirect effect on continued use mediated through stickiness (${\beta}$=0.007, p<0.05). Second, optional participation and prosuming participation significantly formed user participation. Optional participation, with a path magnitude as high as 0.986 (p<0.001), is a key determinant for the strength of user participation. Third, Network effect (${\beta}$=0.236, p<0.001). social influence (${\beta}$=0.135, p<0.05), and usefulness (${\beta}$=0.343, p<0.001) had directly significant impacts on stickiness. But network effect and social influence, as a full mediation model, had both indirectly significant impacts on continued use mediated through stickiness (${\beta}$=0.11, p<0.001, and ${\beta}$=0.063, p<0.05, respectively). Compared with this result, usefulness, as a partial mediation model, had a direct impact on continued use and a indirect impact on continued use mediated through stickiness. This study has three contributions. First this is the first empirical study showing that user participation is the significant driver of continued use. The researchers of information system have hardly studies user participation since late 1990s. And the researchers of marketing have studied a few lately. Second, this study enhanced the understanding of user participation. Up to recently, user participation has been studied from the bipolar viewpoint of participation v.s non-participation. Also, even the study on participation has been studied from the point of limited optional participation. But, this study proved the existence of prosuming participation to design and produce products or services, besides optional participation. And this study empirically proved that optional participation and prosuming participation were the key determinant for user participation. Third, our study compliments traditional studies of TAM. According prior literature about of TAM, the constructs of network effect, social influence, and usefulness had effects on the technology adoption. This study proved that these constructs still are significant on Internet communities.

• KDI Journal of Economic Policy
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• v.32 no.4
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• pp.153-195
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• 2010

The recent global financial crisis has been the outcome of, among other things, the mismatch between institutions and the reality of the market in the current global financial system. The International financial institutions (IFIs) that were designed more than 60 years ago can no longer effectively meet the challenges posed by the current global economy. While the global financial market has become integrated like a single market, there is no international lender of last resort or global regulatory body. There also has been a rapid shift in the weight of economic power. The share of the Group of 7 (G7) countries in global gross domestic product (GDP) fell and the share of emerging market economies increased rapidly. Therefore, the tasks facing us today are: (i) to reform the IFIs -mandate, resources, management, and governance structure; (ii) to reform the system such as the international monetary system (IMS), and regulatory framework of the global financial system; and (iii) to reform global economic governance. The main focus of this paper will be the IMS reform and the role of the Group of Twenty (G20) summit meetings. The current IMS problems can be summarized as follows. First, the demand for foreign reserve accumulation has been increasing despite the movement from fixed exchange rate regimes to floating rate regimes some 40 years ago. Second, this increasing demand for foreign reserves has been concentrated in US dollar assets, especially public securities. Third, as the IMS relies too heavily on the supply of currency issued by a center country (the US), it gives an exorbitant privilege to this country, which can issue Treasury bills at the lowest possible interest rate in the international capital market. Fourth, as a related problem, the global financial system depends too heavily on the center country's ability to maintain the stability of the value of its currency and strength of its own financial system. Fifth, international capital flows have been distorted in the current IMS, from EMEs and developing countries where the productivity of capital investment is higher, to advanced economies, especially the US, where the return to capital investment is lower. Given these problems, there have been various proposals to reform the current IMS. They can be grouped into two: demand-side and supply-side reform. The key in the former is how to reduce the widespread strong demand for foreign reserve holdings among EMEs. There have been several proposals to reduce the self-insurance motivation. They include third-party insurance and the expansion of the opportunity to borrow from a global and regional reserve pool, or access to global lender of last resort (or something similar). However, the first option would be too costly. That leads us to the second option - building a stronger globalfinancial safety net. Discussions on supply-side reform of the IMS focus on how to diversify the supply of international reserve currency. The proposals include moving to a multiple currency system; increased allocation and wider use of special drawing rights (SDR); and creating a new global reserve currency. A key question is whether diversification should be encouraged among suitable existing currencies, or if it should be sought more with global reserve assets, acting as a complement or even substitute to existing ones. Each proposal has its pros and cons; they also face trade-offs between desirability and political feasibility. The transition would require close collaboration among the major players. This should include efforts at the least to strengthen policy coordination and collaboration among the major economies, and to reform the IMF to make it a more effective institution for bilateral and multilateral surveillance and as an international lender of last resort. The success on both fronts depends heavily on global economic governance reform and the role of the G20. The challenge is how to make the G20 effective. Without institutional innovations within the G20, there is a high risk that its summits will follow the path of previous summit meetings, such as G7/G8.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1998.10a
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• pp.2-4
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• 1998

Proliferation of Nocardia amarae cells in activated sludge has often been associated with the generation of nuisance foams. Despite intense research activities in recent years to examine the causes and control of Nocardia foaming in activated sludge, the foaming continued to persist throughout the activated sludge treatment plants in United States. In addition to causing various operational problems to treatment processes, the presence of Nocardia may have secondary effects on the fate of heavy metals that are not well known. For example, for treatment plants facing more stringent metal removal requirements, potential metal removal by Nocardia cells in foaming activated sludge would be a welcome secondary effect. In contrast, with new viosolid disposal regulations in place (Code o( Federal Regulation No. 503), higher concentration of metals in biosolids from foaming activated sludge could create management problems. The goal of this research was to investigate the metal sorption property of Nocardia amarae cells grown in batch reactors and in chemostat reactors. Specific surface area and metal sorption characteristics of N. amarae cells harvested at various growth stages were compared. Three metals examined in this study were copper, cadmium and nickel. Nocardia amarae strain (SRWTP isolate) used in this study was obtained from the University of California at Berkeley. The pure culture was grown in 4L batch reactor containing mineral salt medium with sodium acetate as the sole carbon source. In order to quantify the sorption of heavy metal ions to N amarae cell surfaces, cells from the batch reactor were harvested, washed, and suspended in 30mL centrifuge tubes. Metal sorption studies were conducted at pH 7.0 and ionlc strength of 10-2M. The sorption Isotherm showed that the cells harvested from the stationary and endogenous growth phase exhibited significantly higher metal sorption capacity than the cells from the exponential phase. The sequence of preferential uptake of metals by N. amarae cells was Cu>Cd>Ni. The specific surFace area of Nocardia cells was determined by a dye adsorption method. N.amarae cells growing at ewponential phase had significantly less specific surface area than that of stationary phase, indicating that the lower metal sorption capacity of Nocardia cells growing at exponential phase may be due to the lower specific surface area. The growth conditions of Nocardia cells in continuous culture affect their cell surface properties, thereby governing the adsorption capacity of heavy metal. The comparison of dye sorption isotherms for Nocardia cells growing at various growth rates revealed that the cell surface area increased with increasing sludge age, indicating that the cell surface area is highly dependent on the steady-state growth rate. The highest specific surface area of 199m21g was obtained from N.amarae cell harvested at 0.33 day-1 of growth rate. This result suggests that growth condition not only alters the structure of Nocardia cell wall but also affects the surface area, thus yielding more binding sites of metal removal. After reaching the steady-state condition at dilution rate, metal adsorption isotherms were used to determine the equilibrium distributions of metals between aqueous and Nocardia cell surfaces. The metal sorption capacity of Nocardia biomass harvested from 0.33 day-1 of growth rate was significantly higher than that of cells harvested from 0.5- and 1-day-1 operation, indicatng that N.amarae cells with a lower growth rate have higher sorpion capacity. This result was in close agreement with the trend observed from the batch study. To evaluate the effect of Nocardia cells on the metal binding capacity of activated sludge, specific surface area and metal sorption capacity of the mixture of Nocardia pure cultures and activated sludge biomass were determined by a series of batch experiments. The higher levels of Nocardia cells in the Nocardia-activated sludge samples resulted in the higher specific surface area, explaining the higher metal sorption sites by the mixed luquor samples containing greater amounts on Nocardia cells. The effect of Nocardia cells on the metal sorption capacity of activated sludge was evaluated by spiking an activated sludge sample with various amounts of pre culture Nocardia cells. The results of the Langmuir isotherm model fitted to the metal sorption by various mixtures of Nocardia and activated sludge indicated that the mixture containing higher Nocardia levels had higher metal adsorption capacity than the mixture containing lower Nocardia levels. At Nocardia levels above 100mg/g VSS, the metal sorption capacity of activate sludge increased proportionally with the amount of Noeardia cells present in the mixed liquor, indicating that the presence of Nocardia may increase the viosorption capacity of activated sludge.

• The Journal of Industrial Distribution & Business
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• v.2 no.1
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• pp.5-15
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• 2011

Prior to the introduction of the CRM, we need to analyze the characteristics and the situations of the company, and should establish a clear vision of the CRM. And each company should identify elements and technologies for introducing the most suitable CRM for them, and optimize them, with long-term perspective. In addition, it requires the implementation strategy which integrates the existing company's routine marketing activities with the concept of the CRM. According to the implementation strategy, the company should improve the business process which is the most effective in investment step by step, and the information system strategy, which develops system investment gradually, should harmonize with it. First, we recognized that raising the company value is important by maximizing customer lifetime value (LTV) by understanding customer needs, and achieving the company's goal through customer satisfaction. Second, we understood that adopting the CRM should be accompanied by changes in the structure, business process and customer contact channels, and it can be successfully integrated with business when it gets proper understandings and attentions of the management. Third, the reality is that there are few cases of successful implementation of domestic companies, and some companies that successfully implement the system mean nothing but implement the solution for developing the CRM. Therefore, it needs to be observed for the long haul, and it seems that we need to approach more systematically to implementation cases for each industry about implementation of the CRM. Fourth, the CRM is no longer the preserve of major companies, and it is the time that medium and small sized enterprises also need it. Taking lesson from Switzerland's small size store merchants who successfully adopt right size of the CRM for their business, for domestic medium and small sized enterprises, the necessity to develop business through developing the CRM models which fit their situations and maintaining relationships with customers has been grown. Fifth, for adopting the CRM business processes, changing or converting the CRM system to the model which fits the company's situation is important rather than applying the advanced company's CRM system model. In other words, the CRM solution which can maximize their own strength by developing the CRM program that makes the most of features and characteristics of the company should be adopted.

• Food Science and Preservation
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• v.19 no.2
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• pp.193-200
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• 2012

The quality characteristics of $kalopanax$ $pictus$ and Aralica elata shoots during their preservation were investigated according to the salt conditions and storage temperatures to improve the use of the shoots. The results were as follows: the pH of $kalopanax$ $pictus$ shoots duing their storage did not changes with 10% and 12% brine at $4^{\circ}C$ and with 12% brine at $10^{\circ}C$. The pH of $Aralica$ $elata$ shoots is at $4^{\circ}C$ tended to be similar to the $kalopanax$ $pictus$ shoot and decreased at the storage temperature of $10^{\circ}C$. The salinity of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to increase during their storage and did not change significantly as their storage temperature changed. The L values of $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decrease gradually during their storage, and the salt concentrations appeared high. The b value of the $kalopanax$ $pictus$ shoot tended to increase and that of the $Aralica$ $elata$ shoots, to decrease gradually. The a value tended to increase gradually but did not differ with variations in the storage temperatures and salt concentrations. The strength and the hardness of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decreased gradually during their storage and highest in 10% brine at $4^{\circ}C$, and those of $Aralica$ $elata$ shoots were highest in 8-10% brine at $4^{\circ}C$. The Chlorophyll contents of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decrease during their salt storage and did not change significantly as the temperatures and salt concentrations changed. Therefore, it can be concluded that the quality of $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots can be maintained when the are stored in 10% brine at $4^{\circ}C$.

• Geophysics and Geophysical Exploration
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• v.21 no.3
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• pp.171-182
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• 2018

We performed the seismic field data processing using an open-source software (Madagascar) to verify if it is applicable to processing of field data, which has low signal-to-noise ratio and high uncertainties in velocities. The Madagascar, based on Python, is usually supposed to be better in the development of processing technologies due to its capabilities of multidimensional data analysis and reproducibility. However, this open-source software has not been widely used so far for field data processing because of complicated interfaces and data structure system. To verify the effectiveness of the Madagascar software on field data, we applied it to a typical seismic data processing flow including data loading, geometry build-up, F-K filter, predictive deconvolution, velocity analysis, normal moveout correction, stack, and migration. The field data for the test were acquired in Gunsan Basin, Yellow Sea using a streamer consisting of 480 channels and 4 arrays of air-guns. The results at all processing step are compared with those processed with Landmark's ProMAX (SeisSpace R5000) which is a commercial processing software. Madagascar shows relatively high efficiencies in data IO and management as well as reproducibility. Additionally, it shows quick and exact calculations in some automated procedures such as stacking velocity analysis. There were no remarkable differences in the results after applying the signal enhancement flows of both software. For the deeper part of the substructure image, however, the commercial software shows better results than the open-source software. This is simply because the commercial software has various flows for de-multiple and provides interactive processing environments for delicate processing works compared to Madagascar. Considering that many researchers around the world are developing various data processing algorithms for Madagascar, we can expect that the open-source software such as Madagascar can be widely used for commercial-level processing with the strength of expandability, cost effectiveness and reproducibility.

• Asia pacific journal of information systems
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• v.24 no.4
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• pp.493-513
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• 2014

With the development of related technologies, Location-Based Services (LBS) are growing fast and being used in many ways. Past LBS studies have focused on adoption of LBS because of the fact that LBS users have privacy concerns regarding revealing their location information. Meanwhile, the number of LBS users and revenues from LBS are growing rapidly because users can get some benefits by revealing their location information. Little research has been done on how LBS affects consumers' information search behavior in product purchase. The purpose of this paper is examining the effect of LBS information filtering on buyers' uncertainty and their information search behavior. When consumers purchase a product, they try to reduce uncertainty by searching information. Generally, there are two types of uncertainties - knowledge uncertainty and choice uncertainty. Knowledge uncertainty refers to the lack of information on what kinds of alternatives are available in the market and/or their important attributes. Therefore, consumers having knowledge uncertainty will have difficulties in identifying what alternatives exist in the market to fulfil their needs. Choice uncertainty refers to the lack of information about consumers' own preferences and which alternative will fit in their needs. Therefore, consumers with choice uncertainty have difficulties selecting best product among available alternatives.. According to economics of information theory, consumers narrow the scope of information search when knowledge uncertainty is high. It is because consumers' information search cost is high when their knowledge uncertainty is high. If people do not know available alternatives and their attributes, it takes time and cognitive efforts for them to acquire information about available alternatives. Therefore, they will reduce search breadth. For people with high knowledge uncertainty, the information about products and their attributes is new and of high value for them. Therefore, they will conduct searches more in-depth because they have incentive to acquire more information. When people have high choice uncertainty, people tend to search information about more alternatives. It is because increased search breadth will improve their chances to find better alternative for them. On the other hand, since human's cognitive capacity is limited, the increased search breadth (more alternatives) will reduce the depth of information search for each alternative. Consumers with high choice uncertainty will spend less time and effort for each alternative because considering more alternatives will increase their utility. LBS provides users with the capability to screen alternatives based on the distance from them, which reduces information search costs. Therefore, it is expected that LBS will help users consider more alternatives even when they have high knowledge uncertainty. LBS provides distance information, which helps users choose alternatives appropriate for them. Therefore, users will perceive lower choice uncertainty when they use LBS. In order to test the hypotheses, we selected 80 students and assigned them to one of the two experiment groups. One group was asked to use LBS to search surrounding restaurants and the other group was asked to not use LBS to search nearby restaurants. The experimental tasks and measures items were validated in a pilot experiment. The final measurement items are shown in Appendix A. Each subject was asked to read one of the two scenarios - with or without LBS - and use a smartphone application to pick a restaurant. All behaviors on smartphone were recorded using a recording application. Search breadth was measured by the number of restaurants clicked by each subject. Search depths was measured by two metrics - the average number of sub-level pages each subject visited and the average time spent on each restaurant. The hypotheses were tested using SPSS and PLS. The results show that knowledge uncertainty reduces search breadth (H1a). However, there was no significant correlation between knowledge uncertainty and search depth (H1b). Choice uncertainty significantly reduces search depth (H2b), but no significant relationship was found between choice uncertainty and search breadth (H2a). LBS information filtering significantly reduces the buyers' choice uncertainty (H4) and reduces the negative relationship between knowledge uncertainty and search breadth (H3). This research provides some important implications for service providers. Service providers should use different strategies based on their service properties. For those service providers who are not well-known to consumers (high knowledge uncertainty) should encourage their customers to use LBS. This is because LBS would increase buyers' consideration sets when the knowledge uncertainty is high. Therefore, less known services have chances to be included in consumers' consideration sets with LBS. On the other hand, LBS information filtering decrease choice uncertainty and the near service providers are more likely to be selected than without LBS. Hence, service providers should analyze geographically approximate competitors' strength and try to reduce the gap so that they can have chances to be included in the consideration set.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.5
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• pp.125-141
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• 2021

The rapidly changing social structure of the digital environment is having a significant impact on economic activities. That is also an important issue for Individuals who want to sustain economic activities and countries that support policies. Non-face-to-face industries have been revitalized due to the problem of human capital utilization attributed to aging population, the real economic recession caused by Corona 19, contraction of face-to-face economic activities, reduction of employment, and job instability. Accordingly, digital media contents based economic activities have become commonplace, and the government's main policy issue is to use human capital effectively for media contents based economic activities. Adaptation to the digital environment has become a necessity, not a choice, for those who wish to continue to be in employment. Therefore, this study analyzed the effects of digital and individual abilities on intention to sustain the economic activity and verified the modulation effect of the role model. In order to achieve the purpose of this research, an online survey was conducted on men and women aged 20 to 80 nationwide, and 382 of the 385 collected questionaires were analyzed. The SPSS 23.0 program was used to analyze this study, and the questionaire questions were measured using the Likert 5-point scale. As a result of the analysis, first, the ability to utilize media contents in digital capacity has a positive impact on the intention to sustain economic activity, and that the higher the ability to utilize the latest digital media contents such as SNS, the more likely the intention to sustain economic activity. Secondly, it was found that the financial strength of individuals' abilities was affected by the negative impact, and that the experiences were affected by positive(+) impact on the intention to sustain economic activity. Thirdly, the social environment has no significant effect on the intention to sustain economic activity. Fourth, it was found that family support amongst social support has a positive impact on the intention to sustain economic activity, and that various emotional support for families has increased intention to sustain economic activity. Fifth, the role model was found to have a positive(+) impact on economic sustainability, while the ability to utilize media content and family support played a modulating role on economic sustainability. Therefore, as a result of this research, the government's policy support for employment and entrepreneurship is required in accordance with digital media content based digital education and human structure in order to sustain economic activities.

• Journal of Korean Philosophical Society
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• v.116
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• pp.411-435
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• 2010

Ken Wilber(1949~) tries to approach integration of philosophy, emphasising the advent of the perennial philosophy in the exchange of scholarships at the present day. He suggests All Quadrant(四象限) for the first step to reach his integrated approach. In addition, his approach concretizes for AQAL(All Quadrant, All Level). His AQAL approach which can be divide into inside/outside, singular/plural, or interobjectivity/intersubjectivity is applied to a lot of fileds such as ecology, management, criminology, medical treatment and its boundary is getting bigger. The merits of Quadrant is that it can solve the problem of the plain(平原), which resolves the strength of subjective interior(cultural contexts) into the external existence(social system). From view of Dongmu Lee Je-ma(1837~1900), a former philosopher, Sa-Sang theory['Affairs-Mind-body-Objects(事心身物)', 'Heaven-Human-nature-Order(天人性命)] is in accord with Wilber in content. In Dongmu's writing, Quadrant(Affairs-Mind-body-Objects') called Sa-Sang theory(四象學) or Sasang Constitional Medicine(四象醫學) is basic component in order to explain the structure of all nature. 'Heaven-Human-nature-Order'; That is, 'Affairs-Mind-body-Objects' results in 'Heaven-Human-nature-Order' focused on human being(human body) in the universe. In other words, Sa-Sang theory is the same as the Wilver's inclusive perspectives from the universe and human being. Dongmu's Sa-Sang theory is compared with C. G. Jung(1875~1961)'s psychology and it helps both fields confirm the foundation and extend the province of application. Comparision of Dongmu's Quadrant with Wilber's is not just analogical reasoning. In comparison, Dongmu's Sa-Sang theory is more delicated and crystallized than Wilber's in medical prospective. Dongmu regards Quadrant not as diseases, but as origin of Physiology and Pathology. And he explains all of their courses as Quadrant.