• Interdisciplinary Bio Central
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• v.3 no.3
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• pp.10.1-10.8
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• 2011

Introduction: Hash functions are computer algorithms that protect information and secure transactions. In response to the NIST's "International Call for Hash Function", we developed a biological hash function using the computing capabilities of bacteria. We designed a DNA-based XOR logic gate that allows bacterial colonies arranged in a series on an agar plate to perform hash function calculations. Results and Discussion: In order to provide each colony with adequate time to process inputs and perform XOR logic, we designed and successfully demonstrated a system for time-delayed bacterial growth. Our system is based on the diffusion of ${\ss}$-lactamase, resulting in destruction of ampicillin. Our DNA-based XOR logic gate design is based on the op-position of two promoters. Our results showed that $P_{lux}$ and $P_{OmpC}$ functioned as expected individually, but $P_{lux}$ did not behave as expected in the XOR construct. Our data showed that, contrary to literature reports, the $P_{lux}$ promoter is bidirectional. In the absence of the 3OC6 inducer, the LuxR activator can bind to the $P_{lux}$ promoter and induce backwards transcription. Conclusion and Prospects: Our system of time delayed bacterial growth allows for the successive processing of a bacterial hash function, and is expected to have utility in other synthetic biology applications. While testing our DNA-based XOR logic gate, we uncovered a novel function of $P_{lux}$. In the absence of autoinducer 3OC6, LuxR binds to $P_{lux}$ and activates backwards transcription. This result advances basic research and has important implications for the widespread use of the $P_{lux}$ promoter.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.202-210
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• 2017

Shear stress is one of the most important mechanical factors used in various fields and is important for the design of artificial channels. Current shear stresses have been used in the past, but there are factors that are difficult to actually measure or calculate, such as bed shear stress and energy slope in the equation used. In particular, the energy slope is a very difficult factor to estimate, and it is difficult to estimate the slope and flow velocity of the boundary layer although the energy slope can be used to obtain the shear stress distribution. In addition, the bed shear stress among the shear stress distribution is very difficult to measure directly, and the research is somewhat slower than the velocity. In this study, we have studied the simple calculation of the average flow velocity and the shear stress distribution using entropy M without reflecting the energy gradient, and we used existing laboratory data to demonstrate the utility of the applied equation. The stress distribution in the graphs was comparatively analyzed. In the case of the uniform flow and the non-uniform flow, the correlation coefficient was almost identical to 0.930-0.998.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.549-564
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• 2017

Not only services that are provided by a single system have been various with the development of the Internet of Things and autonomous software but also new services that are not possible before are provided through collaboration between systems. The collaboration between autonomous systems is similar to the ecosystem configuration in terms of biological viewpoints. Thus, it is called the IT Ecosystem, and this concept has arisen newly in recent years. The IT Ecosystem refers to a concept that achieves a mission of each of a number of heterogeneous systems rather than a single system utilizing their own autonomy as well as achieving the objectives of the overall system simultaneously in order to meet a single common goal. In our previous study, we proposed architecture of elementary level and as well as basic several meta-models to implement the IT Ecosystem. This paper proposes comprehensive reference architecture framework to implement the IT Ecosystem by cleansing the previous study. Among them, a utility function based on cost-benefit model is proposed to solve the dynamic re-configuration problem of system components. Furthermore, a measure of using genetic algorithm is proposed as a solution to reduce the dynamic re-configuration overhead that is increased exponentially according to the expansion of the number of entities of components in the IT Ecosystem. Finally, the utilization of the proposed orchestration framework is verified quantitatively through probable case studies on IT Ecosystem for unmanned forestry management.

• Journal of Distribution Science
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• v.11 no.10
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• pp.55-62
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• 2013

Purpose - The purpose of this study is to suggest a risk factor that significantly explains foreign currency risk premia. In recent years, some studies have found that the performance of the simultaneous consumption risk model improves considerably when tested on foreign currency portfolios, which are constructed based on the international interest rates differentials. However, this paper focuses on the long-run consumption risk factor. In our empirical research, we found that the real excess returns of high interest rate currency portfolios depreciate on average, when the future American long-run consumption growth rate appears low. This makes the high interest rate currency portfolios have relatively high risk premia. Meanwhile, the real excess returns of low interest rate currency portfolios appreciate on average, under the same conditions, which results in relatively low risk premia for these portfolios. Therefore, this long-run consumption risk factor might explain why low interest rate currencies do not appreciate as much as the interest rate differential, and why high interest rate currencies do not depreciate as much as the interest rate differential. Research design, data, methodology - In our explanation, we provide new evidence on the success of long-run consumption risks in currency risk premia by focusing on the long-run consumption risks borne by American representative investors. To uncover the hidden link between exchange rates and long-run consumption growth, we set the eight currency portfolios as our basic assets, which have been built based on the foreign interest rates of eighty countries. As these eight currency portfolios are rebalanced every year, the first group always contains the lowest interest rate currencies, and the last group contains the highest interest rate currencies. Against these basic eight currency portfolios, we estimate the long-run consumption risk model. We use recursive utility framework and the stochastic discount factor that depends on the present value of expected future consumption growth rates. We find that our model is optimized in the two-year period of constructing the durable consumption expectation factor. Our main results surprisingly surpass the performance of the existing benchmark simultaneous consumption model in terms of R², relatively risk aversion coefficient γ, and p-value of J-test. Results - The performance of our model is superior. R², relatively risk aversion coefficient γ, and p-value of J-test of our long-run durable consumption model are 90%, 93%, and 65.5%, respectively, while those of EZ-DCAPM are 87%, 113%, and 62.8%, respectively. Thus, we can speculate that the risk premia in foreign currency markets have been determined by the long-run consumption risk. Conclusions - The aggregate long-run consumption growth risk explains a large part of the average change in the real excess returns of foreign currency portfolios. The real excess returns of high interest rate currency portfolios depreciate on average when American long-run consumption growth rate is low, and the real excess returns of low interest rate currency portfolios appreciate under the same conditions. Thus, the low interest rate currency portfolios allow investors to hedge against aggregate long-run consumption growth risk.

• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.38-44
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• 2011

Cisplatin is widely used for various types of cancers. However, its side effects, most notably, renal toxicity often limit its clinical utility. Although previous metabolomic studies reported possible toxicity markers, they used small number of animals and statistical approaches that may not perform best in the presence of intra-group variation. Here, we identified urinary biomarkers associated with renal toxicity induced by cisplatin using NMR-based metabolomics combined with Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA). Male Sprague-Dawley rats (n=22) were treated with cisplatin (10 mg/kg single dose), and the urines obtained before and after treatment were analyzed by NMR. Multivariable analysis of NMR data presented clear separation between non-treated and treated groups. The OPLS-DA statistical results revealed that 1,3-dimethylurate, taurine, glucose, glycine and branched-chain amino acid (isoleucine, leucine and valine) were significantly elevated in the treated group and that phenylacetylglycine and sarcosine levels were decreased in the treated group. To test the robustness of the approach, we built a prediction model for the toxicity and were able to predict all the unknown samples (n=14) correctly. We believe the proposed NMR-based metabolomics with OPLS-DA approach and the resulting urine markers can be used to augment the currently available blood markers.

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.195-204
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• 2007

The objective of this study was to analyze dietitians' sanitary practices and perceptions of obstacles according to HACCP. Questionnaires were administered to 94 elementary school dietitians in the Gwangju and Jeonnam Regions of South Korea. The data were evaluated by a 5 scale Likert method and statistically analyzed The results of the study are as follows. Each subject was generally characterized as a university graduate 79.8%, with 10 to 15 years experience 37.6%, and in her mid to late thirties 39.4%. We found that direct management was the highest occurring form of food service system 96.8%. With regards to the type of food service operation quantitative service as 60.6%, and partial self-service was 30.9%, 89.4%of all served only lunch. In all, 93.6% of the teams collaborated, while their organic collaboration was 64.9%. When HACCP was applied, sanitary practices scored an average of 4.83, which was significantly higher than 4.62 when HACCP was not applied. The dietitians' perception of sanitary practices was as very high 4.75 of 5. Sanitation, in regards to food management, scored 4.89 among the detailed items. This proves that in relation to food management, sanitation is considered most important. When HACCP was not applied, the perception of obstacles was, on an average, 3.07, which was higher than 2.74 when HACCP was applied. The results for the detailed items, which focused on sanitary practices and different perceptions of obstacles according to HACCP, were as follows. When HACCP was applied, a high mean of 3.32 occurred for facilities and utilities shortages followed by degree of cooperation at 3.22, and then monitoring at 3.01. The item that dietitians viewed as the biggest obstacle was lack of departmental budget support (M=3.46). Other serious obstacles were facilities, facility sanitation, and utility shortages (M=3.38), as well as the aappropriateness of machines and cooking utensils and arrangements in the dining room (M=3.28). Stepwise multiple regression was used to better understand how much these perceptions of obstacles would influence sanitary practices when HACCP was applied. The item analysis of the HACCP obstacles proved that persons involved in food service, except the food service employees, didn't cooperate enough with their food service employees. As a result, this lack of cooperation had a negative effect on sanitary practices. Accordingly, it is necessary to determine the causes of for lack of cooperation and attract the active attention of those involved.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.499-509
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• 2016

The occurrence of sand dust has been steadily increased since 1990 and the amount of damage was also increased. In most of previous studies, ground based observations were used for sand dust analyses, but its high spatio-temporal variability has not been well understood. In this study, satellite aerosol observations were used to overcome current limitations of the sand dust variability in space and time and to estimate associations with morbidity of respiratory and cardiovascular ailments. In general, high AODs were observed in the west part of the Koran peninsula in spring. The reasonable associations between the morbidity and sand dust were observed from April to July with highest positive correlation (~0.6) at three month lags (lag 3). Based on the results, we found a utility of the satellite aerosol observations for sand dust analyses by considering of morbidity effects. In addition, health effect against the sand dust is proved to be examined and smooth medical supplies and prevention of undesired medical expenses would be possible.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.350-357
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• 2017

Purpose: In-situ monitoring of water quality is fundamental to most environmental applications. The high cost and long delays of conventional laboratory methods used to determine water quality, including on-site sampling and chemical analysis, have limited their use in efficiently managing water sources while preventing environmental pollution. The objective of this study was to develop an on-site water monitoring system consisting mainly of an Arduino board and a sensor array of multiple ion selective electrodes (ISEs) to measure the concentration of $NO_3$ ions. Methods: The developed system includes a combination of three ISEs, double-junction reference electrode, solution container, sampling system consisting of three pumps and solenoid valves, signal processing circuit, and an Arduino board for data acquisition and system control. Prior to each sample measurement, a two-point normalization method was applied for a sensitivity adjustment followed by an offset adjustment to minimize the potential drift that could occur during continuous measurement and standardize the response of multiple electrodes. To investigate its utility in on-site nitrate monitoring, the prototype was tested in a facility where drinking water was collected from a water supply source. Results: Differences in the electric potentials of the $NO_3$ ISEs between 10 and $100mg{\cdot}L^{-1}$ $NO_3$ concentration levels were nearly constant with negative sensitivities of 58 to 62 mV during the period of sample measurement, which is representative of a stable electrode response. The $NO_3$ concentrations determined by the ISEs were almost comparable to those obtained with standard instruments within 15% relative errors. Conclusions: The use of the developed on-site nitrate monitoring system based on automatic sampling and two-point normalization was feasible for detecting abrupt changes in nitrate concentration at various water supply sites, showing a maximum difference of $4.2mg{\cdot}L^{-1}$ from an actual concentration of $14mg{\cdot}L^{-1}$.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.115-141
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• 2011

In urban space, public space is publicly or privately owned space freely accessible by the public. Privately owned public space to the public hosts small-scale rest facilities to serve the public in buildings of certain purposes and sizes for the sake of pleasant urban environment. The Building Act and building ordinances formulate a set of criteria for management and easement of construction standards as well as the area. When creating privately owned public space, one can get incentives through the easement of floor space index and height limit. The purposes of this study were to investigate and analyze privately owned public open space, which is freely accessible by the public, and its adjacent streets and to propose plans to improve the regulations for securing privately owned public space for more rational and practical legal applications. The study then proposed some plans to help to increase the quality of privately owned public space including applying the coefficient to suggest the type of privately owned public space fit for the features of the streets and measure the appropriate utility level differently and distinguishing the mandatory items according to the facility regulations in privately owned public space from the ones qualified for additional points in case of installation. The types of privately owned public open space should be applied differently and the content of facilities intended should be different according to whether it will serve as a resting place or grant more importance on traffic by walking, depending on the features of its adjacent streets. The privately owned public space, the frontage space of building, and the adjacent sidewalks should become a whole and be regarded as one space from the integrated perspective. The results of the study claim further significance in that it investigated privately owned open space and roadside across Seoul. They will serve as useful data to solve the problems with the privately owned public space of the city, which destroys spatial continuity by focusing on the quantitative increase of privately owned open space and creating individual privately owned open spaces and builds high-rise buildings alienated from the existing spaces, and to increase the quality of future privately owned public space.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.