• Journal of the Korea Society for Simulation
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• v.29 no.2
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• pp.105-117
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• 2020

Analysis of combat effectiveness is required to consider the concept of tactical cooperative engagement between manned-unmanned weapon systems, in order to predict the required operational capabilities of future weapon systems that meets the concept of 'effect-based synchronized operations.' However, analytical methods such as mathematical and statistical models make it difficult to analyze the effects of complex systems under nonlinear warfare. In this paper, we propose a combat simulation model that can simulate the concept of cooperative engagement between manned-unmanned combat entities based on wireless communications. First, we model unmanned combat entities, e.g., unmanned ground vehicles and drones, and manned combat entities, e.g., combatants and artillery, considering the capabilities required by the future ground system. We also simulate tactical behavior in which all entities perform their mission while sharing battlefield situation information through wireless communications. Finally we explore the feasibility of the proposed model by analyzing combat effectiveness such as target acquisition rate, remote control success rate, reconnaissance lead time, survival rate, and enemy's loss rate under a small-unit armor reconnaissance scenario. The proposed model is expected to be used in war-game combat experiments as well as analysis of the effects of manned-unmanned ground weapons.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1995.12a
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• pp.9-21
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• 1995

A planning support system enhances our ability to use water capacity expansion as an urban growth management strategy. This paper reports the development of capacity expansion modeling of water supply as part of the continuing development of such a planning support system (PEGASUS: Planning Environment for Generation and Analysis of Spatial Urban Systems) to incorporate water supply, This system is designed from the understanding that land use and development drive the demand for infrastructure and infrastructure can have a significant influence on the ways in which land is developed and used. Capacity expansion Problems of water supply can be solved in two ways: 1) optimal control theory, and 2) mixed integer nonlinear programming (MINLP). Each method has its strengths and weaknesses. In this study the MINLP approach is used because of its strength of determining expansion sizing and timing simultaneously. A dynamic network optimization model and a water-distribution network analysis model can address the dynamic interdependence between water planning and land use planning. While the water-distribution network analysis model evaluates the performance of generated networks over time, the dynamic optimization model chooses alternatives to meet expanding water needs. In addition, the user and capacity expansion modeling-to-generate-alternatives (MGA) can generate alternatives. A cost benefit analysis module using a normalization technique helps in choosing the most economical among those alternatives. GIS provide a tool for estimating the volume of demanded water and showing results of the capacity expansion model.

• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.53-64
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• 2012

In this study, the modified cyclic triaxial tests with Joomunjin standard sand are performed for dynamic deformation characteristics, such as Young's moduli and damping ratio. The cyclic triaxial test is equipped with Local Displacement Transducer (LDT) on the outside of a cell which has a range from $10^{-4}$ to $10^{-1}$ of shear strains, ${\gamma}$ (%), instead of conventional cyclic triaxial test which has linear variable displacement transducer (LVDT) with low precision. With the small strain control, tests were carried out at various loading rates, void ratios, and effective confining pressures. Based on the test results, such as dynamic deformation characteristics, shear modulus, and damping ratio, it is found that the test can measure more range of medium strains (0.02-0.2%) than results obtained from conventional test (resonant column test). For the medium strain range, dynamic deformation characteristics investigated by the cyclic triaxial test are also different from those predicted by nonlinear model in conventional test.

• Journal of Korean Society on Water Environment
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• v.34 no.4
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• pp.375-381
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• 2018

The monitoring of phytoplankton biomass and community structure is essential as a first step to control the harmful cyanobacterial blooms in freshwater systems, such as seen in rivers and lakes, due to the process of eutrophication and climate change. In order to quantify the biomass of phytoplankton with a wide range in size and shape, the measurement of cell biovolume along with cell density is required for a comprehensive review on this issue. However, most routine monitoring programs preserve the gathered phytoplankton samples before analysis using chemical additives, because of the constraint of time and the number of samples. The purpose of this study was to investigate the cell biovolume change characteristics of six cyanobacterial species, which are common bloom-causing cyanobacteria in the Nakdong River, after the preservation with Lugol's iodine solution. All species showed a statistically significant difference after the addition of Lugol's iodine solution compared to the live cell biovolume, and the cell biovolume decreased to the level of 34.0 ~ 56.3 % at maximum in each species after the preservation. The nonlinear regression models for determining the shrinkage ratio by a preservation period were derived by using the cell biovolume measured until 180 days preservation of each target species, and the equation to convert the cell biovolume measured after preservation for a certain period to the cell biovolume of viable cell was derived using that formula. The conversion equation derived from this study can be used to estimate the actual cell biovolume in the natural environment at the time of sampling, by using the measured biovolume after the preservation in the phytoplankton monitoring. Moreover this is expected to contribute to the final interpretation of the water quality and aquatic ecosystem impacts due to the cyanobacterial blooms.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.5
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• pp.1-11
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• 2019

Financing plays an important role in the survival and growth of startups. This study investigates key factors that improve startup financing performance. To this end, we analyze the relationship between the proportion of intellectual property and the financing performance. In addition, this study also examine the impact of the founder's education level on the financing of startups, and the moderating effect of the founder's education level on the relationship between intellectual property proportion and financing. Based on the survey data of 331 startups, this study found that the proportion of intellectual property and the financing performance have an inverted U-shaped nonlinear relationship. While the founder's education level has a positive impact on the financing performance, it negatively moderate the relationship between the intellectual property proportion and the financing performance. Through these findings, this study suggests that it is necessary to maintain an adequate proportion of intellectual property in order to maximize startup financing performance. The higher education level of founder enhances the startup financing. Since the founder's education level weaken the effect of intellectual proporty's effect on startup financing, however, startups need to control the proportion of intellectual property to improving financing according to the founder's education level. Based on signal theory, this study proposes a new strategy of intellectual property to enhance startup financing performance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.3
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• pp.189-198
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• 2019

In photogrammetry, single photo resection is a method of determining exterior orientation parameters corresponding to a position and an attitude of a camera at the time of taking a photograph using known interior orientation parameters, ground coordinates, and image coordinates. In this study, we proposed a single photo resection algorithm that determines the exterior orientation parameters of the camera using cosine law and linear equation-based three-dimensional coordinate transformation. The proposed algorithm first calculated the scale between the ground coordinates and the corresponding normalized coordinates using the cosine law. Then, the exterior orientation parameters were determined by applying linear equation-based three-dimensional coordinate transformation using normalized coordinates and ground coordinates considering the calculated scale. The proposed algorithm was not sensitive to the initial values by using the method of dividing the longest distance among the combinations of the ground coordinates and dividing each ground coordinates, although the partial derivative was required for the nonlinear equation. In addition, since the exterior orientation parameters can be determined by using three points, there was a stable advantage in the geometrical arrangement of the control points.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.136-145
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• 2020

Agriculture is the backbone of the economy of most developing countries. In these countries, agriculture or farming is mostly done manually with little integration of machinery, intelligent systems and data monitoring. Irrigation is an essential process that directly influences crop production. The fluctuating amount of rainfall per year has led to the adoption of irrigation systems in most farms. The absence of smart sensors, monitoring methods and control, has led to low harvests and draining water sources. In this research paper, we introduce a 433 MHz Radio Frequency and 2G based Smart Irrigation Meter System and a water prepayment system for rural areas of Tanzania with no reliable internet coverage. Specifically, Ngurudoto area in Arusha region where it will be used as a case study for data collection. The proposed system is hybrid, comprising of both weather data (evapotranspiration) and soil moisture data. The architecture of the system has on-site weather measurement controllers, soil moisture sensors buried on the ground, water flow sensors, a solenoid valve, and a prepayment system. To achieve high precision in linear and nonlinear regression and to improve classification and prediction, this work cascades a Dynamic Regression Algorithm and Naïve Bayes algorithm.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.284-290
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• 2013

This study analyzed the geometric, compressive, cutting and friction properties of oriental melons in order to design a gripper capable of soft handling and a cutter for cutting oriental melon vine among the end effector of oriental melon as a preliminary step for developing the end effector of the robot capable of harvesting oriental melons in protected cultivation. As a result, the average length, diameter at the midpoint, weight, volume and roundness of the oriental melons were 108 mm, 70 mm, 188 g, 333 mL and 3.8 mm. Nonlinear regression analysis was performed on the equation $W=L^a{\times}D_2^b$ with variation of the length (L) and diameter (D2) of the weight (W) of the oriental melons. As a result, it was shown that there was a correlation between a of 2.0279 and b of -0.9998 as a constant value. The average diameter of the oriental melon vine was 3.8 mm, and most vines were distributed within a radius of 5 mm from the center. The average yield value, compressive strength and hardness of the oriental melons were $36.5N/cm^2$, $185.7N/cm^2$ and $636.7N/cm^2$, respectively. The average cutting force and shear strength of the oriental melon vines were $2.87{\times}10^{-2}\;N$ and $5.60N/cm^2$, respectively. The maximum friction coefficient of the oriental melons was rubber of 0.609, followed by aluminium of 0.393, stainless steel of 0.177 and teflon of 0.079. It was considered possible to apply it to the size of the gripper and cutter, turning radius, dynamics of drive motor and selection of materials and their quality in light of the position error and safety factor according to the movement when designing end effector based on the analyzed data.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.3-17
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• 1994

The inhibitory effect of sodium ion on the anaerobic degradation of food waste was studied by an anaerobic batch toxicity assay and inhibition model. The anaerobic degradation activity of food waste spiked with over $2g\;Na^+/L$ of sodium ion was severely inhibited at the initial stage of the exposure. The inhibition response of anaerobic microorganisms on the sodium ion estimated from the methane production was differed according to the concentration of sodium ion. The relative acclimation time(RAT) and methanation rate(RMR), defined as the ratios of initial lag time and maximum methane production rate of the sample spiked with sodium ion to the control. respectively, were used to evaluate the acclimation and inhibitory effects quantitatively on the anaerobic microorganisms. When sodium ion was increased from $2g\;Na^+/L$ to $20g\;Na^+/L$, the RAT was exponentially increased from 18.9 to 90. but the RMR was linearly decreased from 0.97 to 0.02. The effects of sodium ion for the maximum methanation rate, first order kinetic constant and ultimate methane production were well evaluated by a generalized nonlinear expression model. it could be described by the uncompetitive inhibition mode. The sodium ion concentration causing 50% inhibition of methanation activity was about $11g\;Na^+/L$, and the critical sodium ion beyond to compelete inhibition was 20 to $21g\;Na^+/L$. The presented results could be used to obtain the design or operation parameters of the anaerobic process treating food waste of high salt.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.6
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• pp.155-166
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• 2018

The purpose of this study is to analyze the impact of self-efficacy of SMEs' organization members on job engagement and job performance, and to analyze the difference between gender and marital status by applying SEM-ANN analysis. To accomplish the study purpose, 285 valid samples were collected from 400 SMEs' organization members and analyzed. In this study, self - efficacy consisted of three sub-dimensions: self-confidence, self-regulation efficacy, and task difficulty preference. As a result of the analysis, self - efficacy such as self-confidence, self-regulation efficacy, and task difficulty preference had a positive direct effect on job engagement. In addition, self-efficacy and self-control efficacy have a positive effect on job performance, but the preference of task difficulty has no significant effect. In addition, job engagement has a positive(+) effect on job performance, and has a mediating role in the relationship between self-efficacy and job performance. Also, married males preferred self-regulation efficacy, while females preferred self-regulation and self-control efficacy regardless of marital status. The purpose of this study is to present the framework of self-efficacy-job engagement-job performance of SMEs by measuring the self-efficacy related researches mainly in education and service industries, and is meaningful that companies can help to find the basis of management of organization members by gender and marital status of organization members. In addition, the SEM-ANN analysis process of this study is different in that it explains the nonlinear (nonobservative) relationship that can analyze the influence or the combination of the reference variables in the linear (compensatory) relation using the SEM.