• The Journal of Korean Institute of Next Generation Computing
• /
• v.13 no.6
• /
• pp.124-131
• /
• 2017

Recently, drone is extending its range of usability. For example, the delivery, agriculture, industry, and entertainment area take advantage of drone mobilities. To control real drones, it needs huge amount of drone control training steps. However, it is risky; falling down, missing, destroying. The virtual drone system can avoid such risks. We reason that what kinds of technologies are required for building the virtual drone system. First, it needs that the virtual drone authoring tool that can assemble drones with the physical restriction in the virtual environment. We suggest that the drone assembly method that can fulfill physical restrictions in the virtual environment. Next, we introduce the virtual drone simulator that can simulate the assembled drone moves physically right in the virtual environment. The simulator produces a high quality rendering results more than 60 frames per second. In addition, we develop the physics engine based on SILS(Software in the loop simulation) framework to perform more realistic drone movement. Last, we suggest the virtual drone controller that can interact with real drone controllers which are commonly used to control real drones. Our virtual drone system earns 7.64/10.0 user satisfaction points on human test: the test is done by one hundred persons.

• Journal of agriculture & life science
• /
• v.50 no.1
• /
• pp.95-104
• /
• 2016

The objective of this paper is to develop volume equation of street tree and its carbon stock for urban forest in Seoul. To develop the volume equation by major species in Seoul, data for street trees were obtained from four-species (e.g. Gingko biloba, Platanus occidentalis, Zelkova serrata, and Metasequoia glyptostroboides), which accounted for 79% all street trees in Seoul. This study used a variable based on diameter on breast height and four equation for calculating volume. The coefficient of determination, bias, and root mean square error were used to evaluate the precision of four equations. From these methods, the most suitable equations for Platanus occidentalis was aDb, the other was aD+bD2; coefficient of determination upper on 0.873. From the volume equation developed in this research, the estimated carbon stock were derived as about 33,760tC for four-species of urban forest in Seoul. The results of this paper offered volume equation and carbon stock that present growth information for street trees in urban forestry and these can be made available for evaluating the management for carbon in settlement.

• Korea Science and Art Forum
• /
• v.25
• /
• pp.463-475
• /
• 2016

As the transition to the digital age in the late 20th century, the intrinsic value of the craft, the emotional values of human, has been noticed as an alternative to overcome the adverse effects of the modernism of the industrial age. To introduce experimental tries which convergence of contemporary technologies and elements of traditional craft, and to inspire artists and present the new possibility of creation to them who want to take advantage of craft emotion as the elements of creation is the purpose of this study in the current digital technology age. First, the meaning and value of craft in modern times and digital media and hybrid creation environments are theoretically investigated based on previous studies and literature. Second, design cases produced by combining digital technology as a tool and craft elements are classified for substantial understanding of the design. Thirdly, identify the design characteristics presented through case studies and suggest the new possibility of creation. The results of the study are as follows. Reject typical types highlight the functional role and try free express conversion, e.g. form, material, texture, making process etc. Extracts the various elements that can be applied and search combining ways, because the convergence of digital technology and the craft is sufficient to activate the human emotion. Interaction between the craft and the digital medium is made actively. Craft accepts digital form, the craft appeared again as the contents of the digital. the traditional and digital method appropriately fused and utilized depending on the situation in process.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.3A
• /
• pp.193-200
• /
• 2010

Structural design requires simultaneously to ensure safety by considering quantitatively uncertainties in the applied loadings, material properties and fabrication error and to maximize economical efficiency. As a solution, system reliability-based design optimization (SRBDO), which takes into consideration both uncertainties and economical efficiency, has been extensively researched and numerous attempts have been done to apply it to structural design. Contrary to conventional deterministic optimization, SRBDO involves the evaluation of component and system probabilistic constraints. However, because of the complicated algorithm for calculating component reliability indices and system reliability, excessive computational time is required when the large-scale finite element analysis is involved in evaluating the probabilistic constraints. Accordingly, an algorithm for SRBDO exhibiting improved stability and efficiency needs to be developed for the large-scale problems. In this study, a more stable and efficient SRBDO based on the performance measure approach (PMA) is developed. PMA shows good performance when it is applied to reliability-based design optimization (RBDO) which has only component probabilistic constraints. However, PMA could not be applied to SRBDO because PMA only calculates the probabilistic performance measure for limit state functions and does not evaluate the reliability indices. In order to overcome these difficulties, the decoupled algorithm is proposed where RBDO based on PMA is sequentially performed with updated target component reliability indices until the calculated system reliability index approaches the target system reliability index. Through a mathematical problem and ten-bar truss problem, the proposed method shows better convergence and efficiency than other approaches.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.4C
• /
• pp.205-212
• /
• 2008

In this research, the effect of rock mass weathering on the side shear resistance of drilled shaft socketed into igneous-metamorphic rock was investigated. For that, 23 cast-in-place concrete piles with diameters varying from 400mm to 1,500mm were constructed at four different sites, and the static axial load tests were performed to examine the resistant behavior of the piles. A comprehensive field/laboratory testing program at the field test site was also performed to describe the in situ rock mass conditions quantitatively. The side shear resistance of rock socketed piles was found to have no intimate correlation with the compressive strength of the intact rock. However, the global rock mass strength, which was calculated by the Hoek and Brown criteria, was found to closely correlate to the side shear resistance. The ground investigation data regarding the rock mass conditions (e.g. $E_m$, $E_{ur}$, $p_{lm}$, RMR, RQD, j) were also found to be highly correlated with the side shear resistance, showing the coefficients of correlation greater than 0.75 in most cases. Additionally, the applicability of existing methods for the side shear resistance of weathered granite-gneiss was verified by comparison with the field test data. The existing methods which consider the effect of rock mass condition were modified and/or extended for weathered rock mass where mass factor j is lower than 0.15, and RQD is below 50%.

• Maritime Security
• /
• v.6 no.1
• /
• pp.37-56
• /
• 2023

Recently, with the rapid development of ICT(Information and Communication Technology) and AI(Artificial Intelligence) technology industries, the emergence of MASS(Maritime Autonomous Surface Ship), which were thought only in the distant future, is approaching a reality. Along with the development of these amazing technologies, changes in the private law sector, such as liability, compensation for damages, and maritime insurance, as well as in the public law sector, such as maritime safety, marine environment protection, and maintenance of maritime order, have become necessary in the field of maritime law. In particular, with the advent of a new type of ship called MASS that does not have a crew on board, the kind and type of liability, compensation for damages, and insurance contracts in the event of a marine accident will also change. In this paper, the general theory about concept, classification, effectiveness and future of MASS and the general theory about concept and various obligations and responsibilities under the maritime law for discussion of MASS are reviewed. Next, in addition, regarding the problems that may occur in the event of a marine accident from MASS, the status as a ship, the legal relationship of the chartering contract, obligation to exercise due diligence in making the vessel seaworthiness, subject of responsibility, and liability for damages and immunity are reviewed from the perspective of maritime law. In addition, in the degree four of MASS, the necessities of further research to clarify the attributable subjects and standards of responsibility in the event of a marine accident, as well as the necessities of institutional improvement such as technology development, enactment and amendment of law and funding are presented.

• The Korean Journal of Franchise Management
• /
• v.2 no.1
• /
• pp.100-118
• /
• 2011

Since 1990, income has been grown rapidly in Korea. Thus, concerns of environmental pollution and health have been increased among Korea's consumers. As a result of this concern, demand for safe food and agricultural products has been growing in Korea. Recently, purchasing patterns of Korea's consumers have been changed as Korea's society has changed to an aging society, growth of unmarried person, and low birthrate. Korea's consumers prefer to buy only volume that they need. Thus, the volume of agricultural products that they purchase became small. Therefore, retailers should reflect such needs of consumers to their business. The purpose of this study is to build up new strategies in order to make a high profit through customer's satisfaction when selling agricultural products. Using literature review, this study has drawn results. The results of this study is that retailers should lay products with brand in their store and establish trust with customers in oder to make loyal customers. In addition, retailers should prepare individual package of agricultural products for sales of a small volume to keep pace with social changes.

• The Korean Journal of Franchise Management
• /
• v.1 no.1
• /
• pp.19-42
• /
• 2010

Since circulation market whole surface opening, traditional market is real condition that is looked away more gradually to consumer as reasons of international retail firms and domestic enterprise firms to enter distribution industry, internet mail order rapid increase by information-oriented society, the pursuit of upgradation and normalization by elevation of income level and consumption pattern change that consideration convenience with young consumers as the central figure. Therefore, the purpose of this study is to analyze stagnation cause of traditional market and problem within a change of new distribution environment, and to develop new approaches for dealing with domestic traditional market relationship prompting competition through activation example analysis of foreign traditional market and domestic traditional market. The result of the study indicated that there are a lot of cases that are begun by a few's merchant with leadership that has been will which is strong in activation in beginning in market's occasion that succeed in activation. In particular, software side such as operational efficiency or marketing expertise strengthening of management is that effect is high relatively than hardware side market activation. Also essential to the settlement of credit transactions using credit cards is important for expanding the effort, for the expansion of credit card merchant credit card advantage and raise awareness among traders about the expected effects is needed. Though these study finding submits plan that create market ecosystem so that many consumers may become place that could visit naturally and create pleasure and convenience, and time, monetary, psychological value of shopping to traditional market, there is sense.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.630-633
• /
• 2021

Microphones can convert received voice signals to electric signals. They have been widely used in various industries such as radios, smart devices and vehicles. Recently, the demands for small size and high sensitive microphones are increased according to the minimization of wireless earphone with the development of smart phone. A MEMS system is a good candidate for an ultra-small size microphone of a next generation and a read out IC for high sensitive MEMS sensor is researched from many industries and academies. Since the microphone system has a high sensitivity from environment noise and electric system noise, the system requires a low noise power supply and some low noise design techniques. In this paper, a low noise LDO is presented for small size MEMS microphone systems. The input supply voltage of the LDO is 1.5-3.6V, and the output voltage is 1.3V. Then, it can support to 5mA in the light load condition. The integrated output noise of proposed LDO form 20Hz to 20kHz is about 1.9uV. These post layout simulation results are performed with TSMC 0.18um CMOS technology and the size of layout is 325㎛ × 165㎛.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.4
• /
• pp.153-160
• /
• 2023

The process of verifying design concepts and ideas by producing real or equivalent model is essential in the product development process. Against this background, the purpose of this study is to consider the case of developing subjects that can systematically cultivate the ability to produce model from the basic stage to a certain level or higher, focusing on design engineering majors. As a theoretical consideration for this, prior studies related to making such as modeling or prototyping in related areas and majors such as industrial design are considered, followed by Bloom's revised taxonomy model and Hioshi Ishikawa's industrial design program as a methodological consideration for curriculum development. Finally, by applying this, we propose a new course that includes a lecture plan corresponding to the 16th week of learning, which is a general semester of university education. As a result of the study, it was confirmed that producing a physical model was still essential for the development of a new design, and accordingly, it was also necessary to establish a systematic curriculum suitable for the major area. Since the scope of this study extends to the development of subjects, in subsequent studies, it is necessary to consider the contents such as verification and reflection of the utility as competency education through actual application and suggestion of improved subject design.