• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.101-110
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• 2009

The 6LoWPAN(IPv6 Low-power Wireless Personal Area Network) performs IPv6 header compression, TCP/UDP/IGMP header compression, packet fragmentation and re-assemble to transmit IPv6 packet over IEEE 802,15.4 MAC/PHY. However, from the point of view of security. It has the existing security threats issued by IP packet fragmenting and reassembling, and new security threats issued by 6LoWPAN packet fragmenting and reassembling would be introduced additionally. If fragmented packets are retransmitted by replay attacks frequently, sensor nodes will be confronted with the communication disruption. This paper analysis security threats introduced by 6LoWPAN fragmenting and reassembling, and proposes a re-transmission mechanism that could minimize re-transmission to be issued by replay attacks. Re-transmission procedure and fragmented packet structure based on the 6LoWPAN standard(RFC4944) are designed. We estimate also re-transmission delay of the proposed mechanism. The mechanism utilizes timestamp, nonce, and checksum to protect replay attacks. It could minimize reassemble buffer overflow, waste of computing resource, node rebooting etc., by removing packet fragmentation and reassemble unnecessary.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.277-280
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• 2021

Recently as various contents are mass produced based on high accessibility, the media contents market is more active. Users want to find content that suits their taste, and each platform is competing for personalized recommendations for content. For an efficient recommendation system, high-quality metadata is required. Existing platforms take a method in which the user directly inputs the metadata of an image. This will waste time and money processing large amounts of data. In this paper, for media hyperpersonalization recommendation, keyframes are extracted based on the YCrCb color model of the video based on movie trailers, movie genres are distinguished through supervised learning of artificial intelligence and In the future, we would like to propose a utilization plan for generating metadata.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.75-84
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• 2020

Modular construction is a construction method whereby prefabricated volumetric units are produced in a factory and are installed on site to form a building block. The construction productivity can be substantially improved by the manufacturing and assembly of standardized modular units. 3D printing is a computer-controlled fabrication method first adopted in the manufacturing industry and was utilized for the automated construction of small-scale houses in recent years. Implementing 3D printing in the fabrication of modular units brings huge benefits to modular construction, including increased customization, lower material waste, and reduced labor work. Such implementation also benefits the large-scale and wider adoption of 3D printing in engineering practice. However, a critical issue for 3D printed modules is the loading capacity, particularly in response to horizontal forces like wind load, which requires a deeper understanding of the building structure behavior and the design of load-bearing modules. Therefore, this paper presents the state-of-the-art literature concerning recent achievement in 3D printing for buildings, followed by discussion on the opportunities and challenges for examining 3D printing in modular construction. Promising 3D printing techniques are critically reviewed and discussed with regard to their advantages and limitations in construction. The appropriate structural form needs to be determined at the design stage, taking into consideration the overall building structural behavior, site environmental conditions (e.g., wind), and load-carrying capacity of the 3D printed modules. Detailed finite element modelling of the entire modular buildings needs to be conducted to verify the structural performance, considering the code-stipulated lateral drift, strength criteria, and other design requirements. Moreover, integration of building information modelling (BIM) method is beneficial for generating the material and geometric details of the 3D printed modules, which can then be utilized for the fabrication.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.390-390
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• 2013

Use of recycled aggregates in portland cement concrete construction can offer benefits associated with both economy and sustainability. Testing performed to date indicates that RBMA can be used as a 100% replacement for conventional coarse aggregate in concrete that exhibits acceptable mechanical properties for use in structural and pavement elements, including satisfactory performance in some durability tests. RBMAC is currently not used in any type of construction in the United States. However, use of RBMAC could become a viable construction strategy as sustainable building practices become the norm. Rating systems such as LEED offer points for reuse of building materials (particularly on-site) and use of recycled materials. If renovations at an existing facility call for the demolition of existing brick masonry constructions, the rubble could be included as RBMA in new concrete pavement, sidewalks, or curb and gutter. Other potential uses for RBMAC could include those in the precast concrete industry, particularly in architectural precast concrete applications. In addition to providing acceptable strength and economy, the color of RBMA could be an attractive component of architectural precast concrete panels or other façade components. This paper explores the feasibility of use of RBMAC in several types of sustainable construction initiatives, based upon the findings of previous work with RBMAC produced from construction and demolition waste from a case study site. Guidance for obtaining and using RBMA is presented, along with a summary of material properties of RBMAC that will be useful to construction professionals.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.721-727
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• 2023

To prevent corruption, waste, and abuse in national governance, audit agencies are established and granted significant authority and responsibilities, including ensuring their independence. However, questions have been raised about who oversees these agencies and addresses issues or misconduct that may arise within them. In the United States, to address this oversight concern, the Inspector General Act was enacted, creating an audit community called the Inspector General Community. This community comprises various audit agencies and promotes compliance with standards and investigates potential wrongdoing by audit personnel. It fosters a culture of independence and collaboration among diverse stakeholders, such as Congress, the President, the Government Accountability Office, and agency leadership. In light of this successful approach in the United States, this research seeks to study and apply similar oversight mechanisms to audit agencies in South Korea. There is a need to develop the relationship between oversight bodies and parliament in terms of improving the efficiency and effectiveness of government operations. Accordingly, this paper studies this American case and presents efficient policy measures for the supervisory system to be applied to Korea's audit organizations. It aims to identify policy insights for effective supervision, ensuring independence, and fostering a collaborative culture within our audit institutions. Therefore, domestic interest and research on this matter are essential to enhance our audit mechanisms and achieve efficient governance.

• Journal of Information Technology Services
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• v.22 no.5
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• pp.31-49
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• 2023

Due to the outbreak of the COVID-19, self-service technology is widely used in Korea, and demand for disposable cups is increasing significantly. Waste and recycling of disposable cups have become a social concern for Koreans and Korea implemented the "Disposable Cup Deposit Systems" again in December 2022. Whether the emergence of this system can change the way people behave in environmental protection is a question to be examined in this study. Companies participating in the disposable cup deposit system are hoping that customers will actively recover cups through self-service in the process of collecting disposable cups. The government, along with businesses, transfers recovery work to customers through self-service technologies and schemes. Due to the increase in Shadow Work and the strengthening of consumer environmental protection consciousness, this paper focuses on how unmanned service types such as self-service technology can affect people's environmental protection behavior. An empirical analysis with 477 samples examined how the characteristics of shadow work, perceived efficacy, environmental awareness, and ecological guilt affect user's environmental protection behavior. Perceived efficacy that acts as a mediator and ecological guilt that plays as a moderator are investigated. Although there have been many studies on the effects of shadow work on customer behavioral intentions before, it has been very rare to study the effects of shadow work perceived by people on environmental behavioral intentions from an environmental protection perspective. This study shows that the higher the perceived efficacy of consumers, the more people prefer self-service technology and the stronger the environmental protection behavior. Also, consumers' ecological guilt significantly moderates the relationship between environmental consciousness and eco-friendly behavior. It is expected that companies and governments will be able to understand the impact of shadow work on consumers' environmental protection behavior and further promote environmental protection by appropriate policies and marketing strategies.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.109-114
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• 2024

Enterprise storage systems that require high data reliability are applying RAID (Redundant Array of Independent Disks) systems to recover from data loss and failure. In particular, RAID 5 ensures space efficiency and reliability by distributing parity across multiple storage devices. However, when storage devices have different capacities, RAID is built based on the smallest capacity storage device, resulting in wasted storage space. Therefore, research is needed to solve this resource management problem. In this paper, we propose a method for RAID grouping of each independent NAND flash memory block in a RAID consisting of SSD (Solid State Disk) with external SSDs as well as internal SSDs. This method is divided into a policy for delivering block information inside SSDs to the RAID system and a policy for RAID grouping of physical addresses delivered from the RAID system. This method allows us to maintain a RAID that does not waste resources when SSDs of different capacities are grouped into RAID5. Finally, we demonstrate the effectiveness of the proposed method through experiments.

• Computers and Concrete
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• v.33 no.6
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• pp.707-724
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• 2024

This paper proposes a study of cement replacement with rice husk ash (RHA) and eggshell ash (ESA) for enhanced mechanical properties of geopolymer (GP) concrete with and without admixture. The main objective is to investigate the mechanical properties of GP with various replacement levels of Pozzolana Portland cement by RHA and ESA. The GP resistance to durability is examined and impact of ash materials on concrete's durability performance is determined. The environmental benefits of using agricultural waste materials in GP manufacturing minimize cement usage and CO2 emissions. The goal is to assess value of RHA-ESA of building material, paving stones for structures to lessen environmental impact. The novelty lies in use of ESA and RHA as partial replacements for cement and investigation of admixtures to enhance concrete properties, and reduce environmental impact. The research contributes by introducing a novel approach to reducing cement consumption by using ESA and RHA to address environmental concerns. It also explores the potential benefits of admixtures improving concrete performance and reducing environmental pollution. A study is carried with and without impacts of admixture to find compressive strength of GP cubes. The cement has been replaced by RHA and ESA in the range of (2.5%+7.5%, 5%+5%, 7.5%+2.5) by weight of cement for M20 mix. The compressive strength (CS) and split tensile strength (STS) at 7days, 14 days and 28 days is obtained as 21 N/mm2 at 7.5%RHA+2.5%ESA and 2.3 at 7.5%RHA+2.5%ESA, 24 N/mm2 at 7.5%RHA+2.5%ESA and 2.3 at 7.5%RHA+2.5%ESA, 28 N/mm2 at 7.5%RHA+2.5%ESA and 2.8 at 7.5%ESA respectively with normal curing condition.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.191-200
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• 2017

Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.

• KDI Journal of Economic Policy
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• v.12 no.3
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• pp.95-123
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• 1990

Advertising, while providing a linkage between sales and consumption, helps promote rational consumption patterns by expanding the scope of information for consumers facing an ever-increasing array of consumption decisions. In so doing, advertising promotes competition among suppliers and sellers, thereby improving market transparency. Intrinsically, advertising can influence the instantaneous decisions made by consumers, and because of this peculiar feature of advertising, ensuring fair advertising practices is a policy issue of great importance. Concurrently, discerning whether the amount of advertising, which is determined by the profit motive of advertisers, is socially appropriate or whether this amount constitutes a waste of scarce resources is a necessary and indispensable consideration in establishing a public policy to respond to the mounting deluge of advertising. Although the Fair Trade Act and numerous other related laws are being enforced with regard to advertising, it may be difficult to say that a unified, practicable and logical basis for regulating the variegated and complex forms of advertising has been established. This paper examines the various theoretical arguments on the welfare effects of advertising as a rationale to justify regulation from the viewpoint of economics. In this manner, this paper helps define the essential nature of advertising and seeks to present a rational approach toward the regulation of advertising.