• The Journal of the Acoustical Society of Korea
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• v.32 no.4
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• pp.287-293
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• 2013

We present a parametric array signal generating system using $3{\times}16$ transducer array which is composed of multi-resonant frequency transducers of 20kHz and 32.5kHz. To drive transducer array, sixteen channel amplifier using LM1875 chips is designed and implemented, and the PXI system based on the LabView 8.6 for arbitrary signal generation and analysis is used. Using the proposed system, we measure sound pressure level and beam pattern of difference frequency and verify the nonlinear effect of difference frequency. The theoretical absorption range and the Rayleigh distance are 15.51m and 1.933m, respectively and we verify that sound pressure of difference frequency is accumulated and increased at the near-field shorter than the Rayleigh distance. We verify that the beam pattern of the measured difference frequency and the beam pattern obtained by the superposition of two primary frequencies are similar, and high directional parametric signal was generated.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.7-18
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• 2007

There are few studies on air pollution due to vehicle emissions in spite of the importance of this field. Therefore, this study describes trends and suggests implications through analysis relating to existing emissions research. This study has been divided into three areas. The first part is about estimating vehicle emissions. In this part, the authors analyze limits in ways of calculating emissions in the existing macroscopic view and then suggest the development of a model for calculating emissions considering velocity and acceleration. These variables are a function of traffic and individual driving behavior in the microscopic view. The second part is about management techniques for reducing vehicle emissions. The traffic management techniques for reducing vehicle emissions should conform to regional characteristics. The final part is about traffic operation for reducing vehicle emissions. The authors suggest the development of a micro-simulator and then the development of strategies for traffic operation. It is necessary to design better models estimating emissions and then, using real time data, to make a monitoring system simulating emission rates. This study serves as a literature review to make a foundation for further research about emissions research for transportation engineering.

• Journal of Advanced Navigation Technology
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• v.14 no.2
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• pp.191-197
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• 2010

Many does an application and application but the image analysis of face detection considerably is difficult. In order for with effect of the illumination which is irregular in the present paper America the illumination to range evenly in the face which is detected, detects a face territory, Complemented the result which detects only the front face of existing. With LAB color illumination revisions compared in Adaboost face detection of existing and 32% was visible the face detection result which improves. Bought two images which are input and executed Glassfire label rings. Compared Area critical price and became the area of above critical value and revised from RGB smooth anger and LAB images with LCFD system algorithm. The operational conversion image which is extracted like this executed a face territory detection in the object. In order to extract the feature which is necessary to a face detection used AdaBoost algorithms. The face territory remote login with the face territory which tilts in the present paper, until Multi-view face territory detections was possible. Also relationship without high detection rate seems in direction of illumination, With only the public PC application is possible was given proof user authentication field etc.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.66-83
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• 2002

The economic feasibility analysis including benefit-cost ratio and internal rate of return of a land consolidation and on-farm development project was mainly depended upon the direct benefits and costs arising during project life. Therefore the projects were neglected in allocating the government's financial funds and loans on account of the low economic rate of return of the project. Accordingly the extended benefit-cost analysis method should be introduced and adapted to cover not only the benefit s such as non-market values of environmental and food security fun ct ions of the project but also market values of the project outputs. The main purposes of this study are (1) to prepare a guide line for economic feasibility analysis based on the IBRD and ADB guidelines, (2) to estimate the benefits from productivity increase, labor saving, savings of O&M cost of farm mechanization and project facilities, savings of farmer's burden for their public health, increasing environmental and public functional value of paddy fields, improving food security condition and formation of peaceful and uncontroversial rural society by implementing the land consolidation and on-farm development, (3) to introduce the newly adapted analytical method as the extended benefit cost analysis which could make possible to be included the values of non-market goods such as the food security and the environmental public function of paddy fields. To carry out this study, the existing publications on the guidelines for economic agricultural projects were reviewed and consultation was made with a For the post evaluation study of the land consolidation and on-farm development project, field survey in Jigok and other comparative area were made to get available information. According to the project completion report, Jigok land consolidation and on-farm development project has 55ha of benefit area out of 69ha of gross area. The project was started in November 11th, 2000 and completed october 30th, 2001. The total project costs were amounted to 2,548 million won and the annual project benefits were estimated at 335million won evaluated by domestic market prices. The ERR(Economic Rate of Return) and SRR(Social Rate of Return) of the project based on the shadow pricing system were estimated at 4.4% and 16% respectively. On the other hand, the ERR and SRR based on the domestic market value system were amounted to 6.37% and 14.62%. In conclusion, Korean land consolidation and on-farm development projects have not carried out from the view point of economic rate of return under shadow pricing system but from the view point of domestic pricing system. For the future feasibility studies on land consolidation projects have to be carried out including the non-market values as environmental and food security function of the projects.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.1
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• pp.1-9
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• 2014

The purpose of this study was to identify the landscape characteristics of Youngnam-Lu by performing text analysis of related Korean poems over 600 years. A total of 354 poems were quantitatively analyzed for keywords and terms in particular categories such as nature. As a subsidiary analysis, topographic map was examined using CAD along with analysis of antique maps. Of the 354 poems reviewed, keywords frequently used are: 'Scenic sites'- 56 times, 'Long river' (長江) and 'Long stretched forest'(長林) - 39 times each, 'Superb scenery'- 31 times, 'Large field scenery'- 19 times, and 'Thousand-layered mountain view' - 14 times. In total, these keywords occurred 159 times in 44.9 % of these poems.1) The words used frequently in these poems, especially for those fall under category of nature, can be scored into different subcategories such as natural phenomena and geographical features. Occurrences of terms in each subcategory were main criteria for the analysis and the following is a list of subcategories with frequency in descending order: Natural phenomena (44%), geographical features (33%), plants (14%), and animals (9%). Among natural phenomena, phenomena related to sky were most frequent, 41 times, which might be due to superb sky view from Youngnam-Lu. Also geographical features of Youngnam-Lu were reflected in these poems, and the most prominent features were 'flow of the river' and 'Sand island' located in the Milyang River. These poems contained fairly large number of terms related to musical instruments (8%) which suggest that Young-Nam-Lu as a place where various musical instruments performances were held.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.542-549
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• 2022

Purpose: Pipes are widely used as applied devices in many industrial fields such as machinery, electronics, electricity, and plants, and are also widely used in safety-related fields such as firefighting and chemistry. With the diversification of products, the importance of technology in the piping field is also increasing. In particular, when changing the existing copper pipe to stainless steel, it is necessary to evaluate safety and flow characteristics through structural analysis or flow analysis. Method: This study investigated the structural stability of the 6.35 and 15.88 socket models, which are integrated insert type connectors developed by a company, using FEM. For structural analysis, HyperMesh as pre-processor, HYPER VIEW as post-processor, and LS-DYNA as solver were used. Result: In the case of 6.35 socket, the maximum stresses at hook, holder and hinge were 95.02MPa, 19.59MPa and 44.01MPa, respectively, and in case of 15.88 socket, it was 127.7 MPa, 40.09MPa and 45.23MPa, respectively. Conclusion: Comparing the stress distribution of the two socket models, the stress in the 15.88 socket, which has a relatively large outer diameter, appears to be large overall, but it is significantly lower than the yield stress of each material, indicating that there is no problem in structural safety in both models.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.119-128
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• 2011

This paper deals with a study on mission analysis considering the effectiveness measurement of UAV system operations. This mission analysis process is composed of 5 steps; (1) creation of a base model in MANA, (2) design of input parameter set using experiment design, (3) mapping input parameter set to the MANA scenario file, (4) data farming and model run in batch process, and (5) statistical analysis of the simulation result. In the result of this study, the effect of input parameter to the dependent parameter was shown to decrease in the order classification range, sweep width, height, speed, FOV(Field of view), and classification probability. The study also shows that the operational effectiveness of an improved scenario proposed can increase 10.2% from the base scenario.

• International Journal of Highway Engineering
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• v.20 no.3
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• pp.85-92
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• 2018

PURPOSES : In this study, analyze the characteristics of IOC indicator 'threshold' which is needed when evaluating the traffic signal operation status with ESPRESSO in various grade road traffic environment of Seoul metropolitan city and derive suggested value to use in field practice. METHODS : Using the computerized database program (Postgresql), we extracted data with regional characteristics (Arterial, Collector road) and temporal characteristics (peak hour, non-peak hour). Analysis of variance and Duncan's validation were performed using statistical analysis program (SPSS) to confirm whether the extracted data contains statistical significance. RESULTS : The analysis period of the main and secondary arterial roads was confirmed to be suitable from 14 days to 60 days. For the arterial, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 25 km/h as the critical speed for AM peak hour and night non peak hour. As for the collector road, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 30 km/h as the critical speed for AM peak hour and night non peak hour. CONCLUSIONS : It is meaningful from a methodological point of view that it is possible to make a reasonable comparative analysis on the signal intersection pre-post analysis when the signal operation DB is renewed by breaking the existing traffic signal operation evaluation method.

• Progress in Medical Physics
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• v.29 no.2
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• pp.47-52
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• 2018

To investigate the effect of low magnetic field on dose distribution in SABR plans for liver cancer, we calculated and evaluated the dose distribution to each organ with and without magnetic fields. Ten patients received a 50 Gy dose in five fractions using the $ViewRay^{(R)}$ treatment planning system. For planning target volume (PTV), the results were analyzed in the point minimum ($D_{min}$), maximum ($D_{max}$), mean dose ($D_{mean}$) and volume receiving at least 90% ($V_{90%}$), 95% ($V_{95%}$), and 100% ($V_{100%}$) of the prescription dose, respectively. For organs at risk (OARs), the duodenum and stomach were analyzed with $D_{0.5cc}$ and $D_{2cc}$, and the remained liver except for PTV was analyzed with $D_{mean}$, $D_{max}$, and $D_{min}$. Both inner and outer shells were analyzed with the point $D_{min}$, $D_{max}$, and $D_{mean}$, respectively. For PTV, the maximum change in volume due to the presence or absence of the low magnetic field showed a percentage difference of up to $0.67{\pm}0.60%$. In OAR analysis, there is no significant difference for the magnetic field. In both shell structure analyses, although there are no major changes in dose distribution, the largest value of deviation for $D_{max}$ in the outer shell is $2.12{\pm}2.67Gy$. The effect of low magnetic field on dose distribution by a Co-60 beam was not significantly observed within the body, but the dose deposition was only appreciable outside the body.

• The Korean Journal of Franchise Management
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• v.13 no.4
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• pp.1-12
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• 2022

Purpose: In 2020, the franchise industry accomplished a significant growth compared to the previous year, as the number of franchise companies increased by 9.0% while the number of franchise brands increased by 12.5%. Despite growth in size, the Korean franchise industry underwent many negative incidents, such as franchise ownership sales to private equity funds, that led to deterioration of businesses. From this point of view, this study aims to make various proposals to help policy makers develop franchise industry policies by analyzing trends of the current and previous presidential administrations' franchise policies and regulations using newspaper articles. Research design, data and methodology: A total of 7,439 articles registered in Naver API from February 25, 2013 to November 29, 2021 were extracted. Among them, 34 unrelated video articles were deleted, and a total of 7,405 articles from both administrations were used for analysis. The R package was used for word frequency analysis, word clouding, word correlation analysis, and LDA (Latent Dirichlet Allocation) topic modeling. Results: The keyword frequency analysis shows that the most frequently mentioned keywords during the previous administration include 'no-brand', 'major company', 'bill', 'business field', and 'SMEs', and those mentioned during the current administration include 'industry' and 'policy'. As a result of LDA topic modeling, 9 topics such as 'global startups' and 'job creation' from the previous administration, and 10 topics such as 'franchise business' and 'distribution industry' from the current administration were derived. The results of LDAvis showed that the previous administration operated a policy based on mutual growth of large and small businesses rather than hostile regulations in the franchise business, whereas the current administration extended the regulation related to franchise business to the employment sector. Conclusions: The analysis of past two administrations' franchise policy, it can be suggested that franchisors and franchisees may complement each other in developing the Fair Transactions in Franchise Business Act and achieving balanced growth. Moreover, political support is needed for sound development of franchisors. Limitations and future research suggestions are presented at the end of this study.