• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.507-517
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• 2022

The PhotoAcoustic Microscopy (PAM) has been proved to be a useful tool for biological and medical applications due to its high spatial and contrast resolution. PAM is based on transmission of laser pulses and reception of PA signals. Since the strength of PA signals is generally low, not only are high-performance optical and acoustic modules required, but high-performance electronics for imaging are also particularly needed for high-quality PAM imaging. Most PAM systems are implemented with a combination of several pieces of equipment commercially available to receive, amplify, enhance, and digitize PA signals. To this end, PAM systems are inevitably bulky and not optimal because general purpose equipment is used. This paper reports a PA signal receiving system recently developed to attain the capability of improved Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR) of PAM images; the main module of this system is a low noise, wideband signal receiver that consists of two low-noise amplifiers, two variable gain amplifiers, analog filters, an Analog to Digital Converter (ADC), and control logic. From phantom imaging experiments, it was found that the developed system can improve SNR by 6.7 dB and CNR by 3 dB, compared to a combination of several pieces of commercially available equipment.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.179-193
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• 2022

Amid the explosive growth of various metaverse platforms, there is no unified indicator to measure, analyze, and evaluate based on customer experience. Therefore, the usability evaluation factors in metaverse were identified through a heuristic methodology and literature review, to evaluate the metaverse, a two-to three-dimensional virtual world platform. A measurable system was established by subdividing 20 items in 5 fields, including user control, information structure, design and content, and usage environment, derived through Delphi technique. Based on this, after experiencing the actual contents of major metaverse platforms such as Roblox and Zepeto, usability was evaluated and comparative verification was conducted. As a result, it was estimated that metaverse user experience could be improved as its utility was derived relatively high in terms of user control and content. This study constitutes a theoretical contribution by extending the usability evaluation system, which has been widely used in the field of service design, to the fields of extended reality and mixed reality. At the same time, it has practical key findings of providing basic judgment standards to stakeholders in the metaverse field, as well as policy implications for digital capability enhancement and industry revitalization.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.120-129
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• 2023

Marine structures are subject to damage not only from sea salt but also from the adhesion of marine microorganisms and suspended particles, which cause additional damages. In order to prevent this, periodic coating is employed in the case of vessels to maintain the necessary performance. However, it is true that periodic coating is difficult for concrete or steel support structures, and there is a risk of marine environmental pollution. In this study, authors developed an anti-fouling coating agent using eco-friendly materials that possess hydrophilic cellulose nanofibers and AKD(alkyl ketene dimer). To achieve a homogeneous mixture, the content of cellulose nanofibers was fixed at 1 %, and AKD, distilled water, and waste glass were mixed using a digital mixer and homogenizer. The contact angle of the prepared coated surface was observed to be over 130°, indicating sufficient performance even in a water droplet flow test with a 15° slope, suggesting self-cleaning capability. Furthermore, through the analysis of viscosity characteristics at different temperatures, it was confirmed that the application is feasible at room temperature. Microstructure analysis also verified that the coating agent is uniformly applied to the concrete surface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.195-202
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• 2006

The infiltration route analysis is a military application using geospatial information technology. The result of the analysis would present vulnerable routes for potential enemy infiltration. In order to find the susceptible routes, optimal path search algorithms (Dijkstra's and $A^*$) were used to minimize the cost function, summation of detection probability. The cost function was produced by capability of TOD (Thermal Observation Device), results of viewshed analysis using DEM (Digital Elevation Model) and two related geospatial information coverages (obstacle and vegetation) extracted from VITD (Vector product Interim Terrain Data). With respect to 50m by 50m cells, the individual cost was computed and recorded, and then the optimal infiltration routes was found while minimizing summation of the costs on the routes. The proposed algorithm was experimented in Daejeon region in South Korea. The test results show that Dijkstra's and $A^*$ algorithms do not present significant differences, but A* algorithm shows a better efficiency. This application can be used for both infiltration and surveillance. Using simulation of moving TOD, the most vulnerable routes can be detected for infiltration purpose. On the other hands, it can be inversely used for selection of the best locations of TOD. This is an example of powerful geospatial solution for military application.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.121-129
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• 2024

The rapid advancement of digital technology and the COVID-19 pandemic have significantly accelerated the growth of online commerce, highlighting the need for support mechanisms that enable small business owners to effectively respond to these market changes. In response, this paper presents a foundational technology leveraging the Online to Offline (O2O) strategy to automatically capture products displayed on retail shelves and utilize these images to create virtual stores. The essence of this research lies in precisely identifying and recognizing the location and names of displayed products, for which a single-class-targeted, lightweight model based on YOLOv8, named ESD-YOLOv8, is proposed. The detected products are identified by their names through feature-point-based technology, equipped with the capability to swiftly update the system by simply adding photos of new products. Through experiments, product name recognition demonstrated an accuracy of 74.0%, and position detection achieved a performance with an F2-Score of 92.8% using only 0.3M parameters. These results confirm that the proposed method possesses high performance and optimized efficiency.

• Journal of Distribution Research
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• v.17 no.5
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• pp.129-146
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• 2012

Recently, Korea became the 7th country in the world which has got into the 20-50 clubs that means the population is 50 million and per capital income is $20,000. From the view point of the retail industry, it suggests that Korea should have its own self-sufficient market by itself. With abundant labor and increased disposable income, it made the consumer's needs change. Responding to the change, retail and F&B oriented retail malls are now starting to add culture, art and entertainment facilities in the configurations. Such complexity and variety of the shopping malls became trendy and many shopping complexes are scheduled to open in the near future across the country. Due to above reasons, it became the common trend to develop shopping complex all over the cities now. However, the history of the shopping mall in Korea is much shorter than developed countries such as America and Japan. Thereby, a lot of problems, trial and error have occurred in the process of developing and operating them. If development of shopping complex failed, it would return lots of damages to the stakeholder. Therefore, the corporations should develop the mall properly and government might support positively. In this study, we would like to propose on how all the mall should be developed and well managed and what are the ways for the vitalizing factors of the shopping complex after benchmarking other shopping mall cases. Through the case study, we realized that the most crucial factors for vitalizing shopping complex were interior design, merchandising and how well they operate the mall. In case of the failed shopping mall, developers sell each store to individual proprietors and never take care of them after they get the profit, which make it hard to have integrated marketing strategies. That causes the overall slump of the mall. Corporations developing the mall should operate it as well, so that it could be possible to make the mall consistently well managed and promoted. There is a certificate for the shopping mall expert in The States and Japan. However, we do not have this kind of certificate. In fact, if we judge the capability of a person who is involved in the shopping mall industry, we usually measure how many years they stick to the same industries and that is not equally the same as their competence. Therefore it is necessary to organize "Shopping Mall Associate" and introduce shopping mall license for the mall expert. Due to retail trends, we can easily see a lot of shopping facilities all over the cities but not every mall is able to be successful. We think it's essential that the government should certify the malls which are qualified for the design, merchandising and proficiency of the operation. For the qualified mall, the government could confer a benefit on the company such as reducing corporation taxes. In multi-complex shopping mall it is possible to make convenient for customers. However, if a mall failed to succeed, it would be disaster. To build a shopping complex, developers should invest huge money even take out loan so that many people would be connected to the project, which may affect their whole financial conditions. In addition, only qualified corporation should develop and operate shopping complex and the government must support and aid the developers in order to make a better shopping environment in which customers might be happy during their shopping experience.

• Journal of the HCI Society of Korea
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• v.11 no.1
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• pp.47-55
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• 2016

Three Dimensional Printing (herein, 3D printing) not only gives novelty and interests to modern people but is also a spotlighted technology that could herald a new industrial revolution. The introduction of various 3D printing service platforms has enabled individuals to easily possess products designed through 3D printing. However, there are still many issues to consider until the era of new manufacturing, when 3D printing becomes available to the general public so that anyone can make and design products with 3D printing. For instance, there needs to be sufficient consideration and research on whether the current 3D printing services can prove their higher capability to produce products conventionally done by machines and hands through 3D printing, and on the meaning of selling a wide range of product families like those of most 3D printing service platforms to the consumers. This study, which was initiated in this context, aimed to gain insight on the directions that 3D printing services need to advance going forward by letting consumers have first-hand experience on 3D printing online service platforms with a wide range of product families and those with relatively limited services, and then asking them to answer multiple-choice and short-answer survey questions on the websites they wish to purchase from, diversity of designs, design satisfaction, perceived technical skills, perceived purchase satisfaction, perceived after-sales service(A/S). As a result, we were able to witness that consumers generally had a strong preference for services with a wide range of product families (e.g. Shapeways) compared to services with a narrow range (e.g. Digital Forming). We also verified that design diversity and the possibility of realizing the designs were the crucial aspects that need to be considered with 3D printing services. Moreover, we also carried out discussions on carrying out design consulting by securing a pool of designers from diverse fields, on providing web-based designing software that can be utilized even by beginners, and on operating shops both online and offline in order to provide more competitive 3D printing services.

• Progress in Medical Physics
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• v.14 no.2
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• pp.124-130
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• 2003

Currently, as a consequence of PACS (Picture Archiving Communication System) implementation many hospitals are replacing conventional film-type interpretations of diagnostic medical images with new digital-format interpretations that can also be saved, and retrieve However, the big limitation in PACS is considered to be the lack of mobility. The purpose of this study is to determine the optimal communication packet size. This was done by considering the terms occurred in the wireless communication. After encoding medical image using JPGE2000 image compression method, This method embodied auto-error correction technique preventing the loss of packets occurred during wireless communication. A PC class server, with capabilities to load, collect data, save images, and connect with other network, was installed. Image data were compressed using JPEG2000 algorithm which supports the capability of high energy density and compression ratio, to communicate through a wireless network. Image data were also transmitted in block units coeded by JPEG2000 to prevent the loss of the packets in a wireless network. When JPGE2000 image data were decoded in a PUA (Personal Digital Assistant), it was instantaneous for a MR (Magnetic Resonance) head image of 256${\times}$256 pixels, while it took approximately 5 seconds to decode a CR (Computed Radiography) chest image of 800${\times}$790 pixels. In the transmission of the image data using a CDMA 1X module (Code-Division Multiple Access 1st Generation), 256 byte/sec was considered a stable transmission rate, but packets were lost in the intervals at the transmission rate of 1Kbyte/sec. However, even with a transmission rate above 1 Kbyte/sec, packets were not lost in wireless LAN. Current PACS are not compatible with wireless networks. because it does not have an interface between wired and wireless. Thus, the mobile JPEG2000 image viewing system was developed in order to complement mobility-a limitation in PACS. Moreover, the weak-connections of the wireless network was enhanced by re-transmitting image data within a limitations The results of this study are expected to play an interface role between the current wired-networks PACS and the mobile devices.

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.213-222
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• 1998

Electro-Optical Camera(EOC) is the main payload of the KOrea Multi-Purpose SATellite(KOMPSAT) with the mission of cartography to build up a digital map of Korean territory including a Digital Terrain Elevation Map(DTEM). This instalment which comprises EOC Sensor Assembly and EOC Electronics Assembly produces the panchromatic images of 6.6 m GSD with a swath wider than 17 km by push-broom scanning and spacecraft body pointing in a visible range of wavelength, 510~730 nm. The high resolution panchromatic image is to be collected for 2 minutes during 98 minutes of orbit cycle covering about 800 km along ground track, over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The image of 8 bit digitization, which is collected by a full reflective type F8.3 triplet without obscuration, is to be transmitted to Ground Station at a rate less than 25 Mbps. EOC was elaborated to have the performance which meets or surpasses its requirements of design phase. The spectral response, the modulation transfer function, and the uniformity of all the 2592 pixel of CCD of EOC are illustrated as they were measured for the convenience of end-user. The spectral response was measured with respect to each gain setup of EOC and this is expected to give the capability of generating more accurate panchromatic image to the users of EOC data. The modulation transfer function of EOC was measured as greater than 16 % at Nyquist frequency over the entire field of view, which exceeds its requirement of larger than 10 %. The uniformity that shows the relative response of each pixel of CCD was measured at every pixel of the Focal Plane Array of EOC and is illustrated for the data processing.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.2
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• pp.171-186
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• 2023

CEOs who have started and managed small and medium-sized enterprises (SMEs) have a lot of concerns about the sustainability of their businesses in the fierce management field and sometimes have the intention to discontinue their businesses. In this study, the perception of the business environment of SMEs (intensity of competition, difficulty in manpower management), the competency of the corporate (employee competency, product or service competitiveness, digital or technical capability), the competency of the CEO's (management competency and health status of CEO), and the perception of business succession on the CEO's intention to discontinue business were empirically studied with SME CEOs. This study conducted a survey of SME CEOs in various industries from March 20 to April 15, 2022, and verified the research hypothesis using SPSS 24.0 with 296 samples obtained. As a result of the study, the intensity of competition, the difficulty in manpower management, and the perception of business succession had a positive (+) effect on the intention to discontinue the business. On the other hand, the employee competency, the product or service competitiveness, the corporate digital or technical competency, and the CEO's health status had a negative (-) effect on the intention to discontinue business. Meanwhile, it was observed that government regulations also have a moderating effect on the intensity of competition, the difficulty in manpower management, the business succession perception of CEO, and the intention to discontinue business. This study has academic significance in that the concept of 'discontinuing business', which was fragmentarily scattered according to various preceding studies, was systematized based on the level of ownership change and voluntariness. And that it empirically analyzed factors related to the intention to discontinue business targeting SME CEOs. In addition, that it observed for the baby-boomer CEOs in Korea the factors influencing the intention to discontinue business and that it was confirmed that considering their age, organizing the business stable and handing it over to the successor was another positive concept of business discontinuation.