• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.4
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• pp.99-116
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• 2018

The purpose of this study is to suggest the integrated entrepreneurial competency models that reflect critical entrepreneurial competencies that entrepreneurs should have at different stages, thereby enhancing the success rate of ventures. To accomplish the purpose, this study developed the hypotheses about the positive effects of entrepreneurial competencies on business performance, and the moderating effect of learning competency to strengthen the relationship between entrepreneurial competencies and business performance. The results of this study are as follows. First, the technological functional competency of entrepreneurial teams, the resource utilization and business planning competency of entrepreneurs in the early stage of business development were found to significantly affect both non-financial and technological performance. The opportunity recognition competency has a significantly positive effect on non-financial performance. In addition, it is analyzed that learning competency significantly moderated the relationship between entrepreneurial competencies(technological functional, resource utilization) and non-financial performance. The moderating effect of learning competency between business planning competency and technological performance was also found to be significant. Second, leadership and resource acquisition competency of entrepreneurs in the late stage of ventures have significantly positive effects on both non-financial and technological performance. The strategic competency has a significantly positive effect on non-financial performance. It was also found that the moderating effect of learning competency between strategic competency and non-financial performance was significant. Finally, the results show that both non-financial and technical performance of NTBVs are significant determinants of financial performance.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.469-478
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• 1997

This study was conducted to develop an automatic nutrient-solution mixing system for small-scale sewers. The nutrient-solution mixing system consisted of a low-cost and precise metering device and data acquisition ＆ control system with a personal computer. and, the metering device was composed of three parts those were supply pumps, metering cylinders and venturi tube. The system controlled electric conductivity(EC) and pH of nutrient-solution based on the time-based feedback control method with the information about temperature, EC, and pH of the nutrient-solution. The performance of the nutrient-solution mixing system was evaluated through the control of EC and pH while compared with those of commercial system. Also an experimental cultivation of tomato was conducted to verify and to improve the developed system. Results of this study were as follows. 1. The correlation coefficient of meteing device between the flow rate and operating time was 0.9999, and the linear reuession equation computed was y=21.759x, where y is the discharge($g$) and x is the operating time(s). 2. Calculated errors for the developed metering device and two commercial pump were $\pm$0.3% $\pm$2.45% and $\pm$1.38 % FS error respectively. 3. An automatic nutrient-solution mixing system based on a low-cost and precise metering device was developed. 4. The full scale errors of the developed system in controlling EC and pH at 23$\pm$1$^{\circ}C$ were $\pm$0.05mS/cm and $\pm$0.2, respectively 5. When using the commercial system, the controlled values of EC and pH of the 500 $\ell$ of water were 1.29 mS/cm and 6.1 pH for the setting points of 1.4 mS/cm and 6.0 pH respectively at 23$pm1^{\circ}C$. 6. The developed nutrient-solution control system showed $\pm$0.05 ms/cm of deviation from the setting EC value over the experimental cultivation period. 7. The deviation from the average values of Ca and Mg mass content in the several nutrient-solution were 0.5% and 1.8% respectively.

• The Mathematical Education
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• v.57 no.1
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• pp.1-36
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• 2018

The purpose of this study is to examine the relationship between utilization of technology and TPACK in mathematics teachers, and to analyze needs and retentions, difference between needs and retentions, and educational needs of TPACK in mathematics teachers. Furthermore, we will prioritize TPACK items that mathematics teachers want to change, and provide implications for teacher education related to TPACK in the future. To do this, we analyzed 328 mathematics teachers nationwide by using survey on the utilization of technology, averages of TPACK's needs and retentions, t-test of two averages, Borich's educational needs analysis, and the Locus for Focus model. The results are as follows. Firstly, the actual utilization rate was lower than the positive recognition of utilization of technology by mathematics teachers, and many mathematics teachers mentioned the lack of knowledge related to TPACK. Secondly, the characteristics of in-service mathematics teacher's needs and retentions for TPACK were clear, and TPACK's starting line of in-service mathematics teacher can be different from pre-mathematics teacher's. The retentions was high in the order of CK, PCK and PK, and the needs was higher in the order of TPACK, TCK, TK and TPK. All of the higher retentions were knowledge related to PCK, and the value of CK was extremely high among them. In addition, mathematics teachers recognized needs for integrated knowledge related to technology, and they needed more TCK than TPK. The difference between needs and retentions showed that all items except two items in the PK were significant. Retentions of all items in CK was higher than needs, needs of all items in TK, TCK, TPK and TPACK was higher than retentions, PK and PCK were mixed. Thirdly, based on the analysis of Borich's educational needs and the Locus for Focus model, teacher education on TPACK for mathematics teachers needs to focus on TPACK, TK, TCK, and TPK. Specifically, TPACK needs to combine technology in terms of creativity-convergence, mathematical connections, communication, improvement of evaluation quality, and TK needs to new technology acquisition, function of utilizing technology, troubleshoot problems with technology, TCK needs to mathematical value(esthetic, practical) with technology, and TPK needs to consider technology in terms of evaluation methods, teaching and learning methods, improvement of pedagogy. Therefore, when determining the direction of teacher education related to TPACK in the future, if they try to reflect these items in detail, the teachers could participate more actively and receive practical help.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.431-437
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• 2018

We analyzed the feasibility of detecting wave gliders moving on the sea surface using SAR images. For the experiment, a model was constructed and placed on the sea using a towing ship before and after the satellite observation time. In the acquisition of KOMPSAT-5 image, high resolution SAR data of spotlight mode was collected considering the small size of wave glider. As a result of the backscattering intensity analysis around the towing ship along with wave glider, several scattering points away from the ship were observed, which are not strong but clearly distinguished from the surrounding clutter values. Considering the distance from the center of the ship, it seems to be a signal by the wave glider. On the other hand, it is confirmed that the wave glider can be detected even at the very low false alarm rate ($10^{-6}$) of the target detection using CFAR. Although the scatter signal by the wave glider could be distinguished from the surrounding ocean clutter in the high resolution SAR image, further research is needed to determine if actual wave gliders are detected in various marine environments.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.48-53
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• 1995

This study investigates a simple mathematical model for the quantitative estimation of regional myocardial blood flow in experimental canine coronary artery thrombosis using Rb-82 dynamic myocardial positron emission tomography. The coronary thrombosis was induced using the new catheter technique by narrowing the lumen of coronary vessel gradually, which finally led to partial obstruction of coronary artery. Ten Rb-82 dynamic myocardial PET scans were performed sequentially for each experiment using our 5, 10 and 20 second acquisition protocol, respectively, and three regions of interest were drawn on the transaxial slices, one on left ventricular chamber for input function and the other two on normal and decreased perfusion segments for the flow estimation in those regions. Single compartment model has been applied to the measured sets of regional PET data, and the rate constants of influx to myocardial tissue were calculated for regional myocardial flow estimates with the three parameter fits of raw data by the Levenberg-Marquardt method. The results showed that, (1) single compartment model suggested by Kety-Schmidt could be used for the simple estimation of regional myocardial blood flow, (2) the calculated regional myocardial blood flow estimates were dependent on the selection of input function, which reflected partial volume effect and left ventricular wall motion, and (3) mathematically fitted input and tissue time activity curves were more suitable than the direct application of the measured data in terms of convergence.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.124-130
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• 1998

High-speed 3D vision systems are essential for autonomous robot or vehicle control applications. In our study, a stereo vision process has been developed. It consists of three steps : extraction of edges in right and left images, matching corresponding edges and calculation of the 3D map. This process is implemented in a VME 150/40 Imaging Technology vision system. It is a modular system composed by a display, an acquisition, a four Mbytes image frame memory, and three computational cards. Programmable accelerator computational modules are running at 40 MHz and are based on TMS320C31 DSP with a $64{\times}32$ bit instruction cache and two $1024{\times}32$ bit internal RAMs. Each is equipped with 512 Kbytes static RAM, 4 Mbytes image memory, 1 Mbytes flash EEPROM and a serial port. Data transfers and communications between modules are provided by three 8 bit global video bus, and three local configurable pipeline 8 bit video bus. The VME bus is dedicated to system management. Tasks between DSPs are distributed as follows: two DSPs are used to edges detection, one for the right image and the other for the left one. The last processor computes the matching process and the 3D calculation. With $512{\times}512$ pixels images, this sensor generates dense 3D maps at a rate of about 1 Hz depending of the scene complexity. Results can surely be improved by using a special suited multiprocessors cards.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.376-380
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• 2013

Determination of PFOS in instant food packing materials by LC-MS/MS was developed. The procedure involves an extraction of the Food Packing Materials with 100% methanol soxcelet extraction method. The LC separation was performed by Hypersil Gold ($150mm{\times}2.1mm$ 5 um) with mobile phases of 2 mM amoniumacetate solution and acetonitrile. The Mass spectral acquisition was done in negative ESI/SRM using the TSQ Quantum Ultra. With this method, good linear relationship, sensitivity and reproducibility were obtained. The rate of recoveries of PFOS from paper material spiked with 1.0 ug/L were 99.84%, respectively. The limit of quantitation and limit of detection were below 0.03 ug/L and 0.009 ug/L. The method had been applied to determination of PFOS in instant food packing materials.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.337-346
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• 2003

This paper describes on the system and method for automatically tracking and real-time monitoring the position of target ships relative to the own ship using a PC based radar system that displays radar images and electronic charts together on a single PC screen. This system includes a simulator for generating the GGA and VTG information of target ships and a simulator for generating the TTM and OSD outputs from a ARPA radar and then host computer accepts NMEA0183 sentences on the maneuvering information of target ships from these simulators. The results obtained are summarized as follows；1. The system developed this study can be used as a range finder for measuring the distance between two ships and as a device for providing the maneuvering information such as distance and bearing to target ships from own ship on ECS screen. 2. From the result of position tracking for a selected target ship tracked with an update rate of 5 seconds using the $\alpha$-$\beta$ tracker, we concluded that the smoothing effect by the $\alpha$-$\beta$tracker was very effective and stable except in the time interval until about one minute after the target is detected. 3. From the fact that the real-time maneuvering information of tracked ship targets via a local area network (LAN) from a host computer installed a radar target extractor was successfully transferred to various monitoring computers of ship, we concluded that this system can be used as a sub-monitoring system of ARPA radar.

• Survey Research
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• v.7 no.2
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• pp.53-69
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• 2006

Weights can be made and imposed in both sample design stage and analysis stage in a sample survey. While in design stage weights are related with sample data acquisition quantities such as sample selection probability and response rate, in analysis stage weights are connected with external quantities, for instance population quantities and some auxiliary information. The final weight is the product of all weights in both stage. In the present paper, we focus on the weight in analysis stage and investigate the effect of such weights imposed on the weighted mean when estimating the population mean. We consider a finite population with a pair of fixed survey value and weight in each unit, and suppose equal selection probability designs. Under the condition we derive the formulas of the bias as well as mean square error of the weighted mean and show that the weighted mean is biased and the direction and amount of the bias can be explained by the correlation between survey variate and weight: if the correlation coefficient is positive, then the weighted mein over-estimates the population mean, on the other hand, if negative, then under-estimates. Also the magnitude of bias is getting larger when the correlation coefficient is getting greater. In addition to theoretical derivation about the weighted mean, we conduct a simulation study to show quantities of the bias and mean square errors numerically. In the simulation, nine weights having correlation coefficient with survey variate from -0.2 to 0.6 are generated and four sample sizes from 100 to 400 are considered and then biases and mean square errors are calculated in each case. As a result, in the case or 400 sample size and 0.55 correlation coefficient, the amount or squared bias of the weighted mean occupies up to 82% among mean square error, which says the weighted mean might be biased very seriously in some cases.

• Tuberculosis and Respiratory Diseases
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• v.81 no.2
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• pp.99-105
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• 2018

Acute exacerbation(s) of chronic obstructive pulmonary disease (AECOPD) tend to be critical and debilitating events leading to poorer outcomes in relation to chronic obstructive pulmonary disease (COPD) treatment modalities, and contribute to a higher and earlier mortality rate in COPD patients. Besides pro-active preventative measures intended to obviate acquisition of AECOPD, early recovery from severe AECOPD is an important issue in determining the long-term prognosis of patients diagnosed with COPD. Updated GOLD guidelines and recently published American Thoracic Society/European Respiratory Society clinical recommendations emphasize the importance of use of pharmacologic treatment including bronchodilators, systemic steroids and/or antibiotics. As a non-pharmacologic strategy to combat the effects of AECOPD, noninvasive ventilation (NIV) is recommended as the treatment of choice as this therapy is thought to be most effective in reducing intubation risk in patients diagnosed with AECOPD with acute respiratory failure. Recently, a few adjunctive modalities, including NIV with helmet and helium-oxygen mixture, have been tried in cases of AECOPD with respiratory failure. As yet, insufficient documentation exists to permit recommendation of this therapy without qualification. Although there are too few findings, as yet, to allow for regular andr routine application of those modalities in AECOPD, there is anecdotal evidence to indicate both mechanical and physiological benefits connected with this therapy. High-flow nasal cannula oxygen therapy is another supportive strategy which serves to improve the symptoms of hypoxic respiratory failure. The therapy also produced improvement in ventilatory variables, and it may be successfully applied in cases of hypercapnic respiratory failure. Extracorporeal carbon dioxide removal has been successfully attempted in cases of adult respiratory distress syndrome, with protective hypercapnic ventilatory strategy. Nowadays, it is reported that it was also effective in reducing intubation in AECOPD with hypercapnic respiratory failure. Despite the apparent need for more supporting evidence, efforts to improve efficacy of NIV have continued unabated. It is anticipated that these efforts will, over time, serve toprogressively decrease the risk of intubation and invasive mechanical ventilation in cases of AECOPD with acute respiratory failure.