• Journal of the Korea Convergence Society
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• v.10 no.7
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• pp.281-287
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• 2019

Application of heat recovery system applying air supply and cexhaust ventilation device essential in energy management system for the optimum ventilation system utilization and energy saving. This is a key element of infrastructure technology for high-efficiency energy buildings, because it can save heating and cooling energy in winter and summer. In this paper, heat transfer efficiency was simulated using paper, plastic, and aluminum materials that was examined to compare heat exchanger performance under uniform flow conditions. We tested heat transfer efficiengy according to the shape of two of that, one is orthogonal and the other is refraction shape. Based on the simulation results, it is expected to contribute to the production of high performance heat exchanger with heat transfer performance and pressure loss.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.515-522
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• 2018

Current signs of a downturn in South Korea's economy include the sharp drop in consumption. Considering internal and external complications such as the raise in minimum wage and fierce global competition, people's taste and purpose of consumption is shifting as well. Under such circumstances, crowdfunding provides a new investment and distribution channel for businesses in their initial stages. Crowdfunding can serve as a key driver of growth in early stages of business operations and lead to growth in consumption as a new distribution channel. This study explores how customers perceive the process of reward crowdfunding, especially when it comes to fairness in procedure, interaction, and distribution. In addition, we further seek how perceived fairness affects customer satisfaction and loyalty in the industry.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.4
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• pp.25-34
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• 2021

Objectives This study was conducted to evaluate the therapeutic effect of acupuncture after rotator cuff surgery. Methods Key words such as rotator cuff surgery and acupuncture were searched in 10 databases (Ovid-Medline, Ovid-EMBASE, Ovid-AMED, Cochrane Library, China National Knowledge Infrastructure [CNKI], National Digital Science Library [NDSL], Koreanstudies Information Service System [KISS], Oriental medicine Advanced Searching Integrated System [OASIS], KoreaMed, KMBASE), and only suitable randomized controlled trials (RCTs) were selected. Results 6 RCTs were finally selected, and acupuncture showed positive results for pain relief and functional recovery after rotator cuff surgery. However, the analyzed 6 RCTs showed a high overall risk of bias. Conclusions In the future, RCTs with a higher level of evidence on the effect of acupuncture after rotator cuff surgery need to be continuously conducted.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.4
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• pp.35-47
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• 2021

Objectives This study was conducted to evaluate the therapeutic effect of herbal medicine after total knee arthroplasty. Methods Key words such as total knee arthroplasty and herbal medicine were searched in 10 databases (Ovid-Medline, Ovid-EMBASE, Ovid-AMED, Cochrane Library, China National Knowledge Infrastructure [CNKI], National Digital Science Library [NDSL], Koreanstudies Information Service System [KISS], Oriental medicine Advanced Searching Integrated System [OASIS], KoreaMed, KMBASE), and only suitable randomized controlled trials (RCTs) were selected. Results 8 RCTs were finally selected, and herbal medicine showed positive results for pain relief and functional recovery after total knee arthroplasty. However, the analyzed 8 RCTs showed a high overall risk of bias. Conclusions In the future, RCTs with a higher level of evidence on the effect of herbal medicine after total knee arthroplasty need to be continuously conducted.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.1
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• pp.29-40
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• 2005

In this paper we consider the security of recently proposed software-orienred stram cipher HELIX, SCREAM, MUGI, and PANAMA against algebraic attacks. Algebraic attack is a key recovery attack by solving an over-defined system of multi-variate equations with input-output pairs of an algorithm. The attack was firstly applied to block ciphers with some algebraic properties and then it has been mon usefully applied to stream ciphers. However it is difficult to obtain over-defined algebraic equations for a given cryptosystem in general. Here we analyze recently proposed software-oriented stream ciphers by constructing a system of equations for each cipher. furthermore we propose three design considerations of software-oriented stream ciphers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.61-70
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• 2011

Virtualization is a technology that uses a logical environment to overcome physical limitations in hardware. As a part of cost savings and green IT policies, there is a tendency in which recent businesses increase the adoption of such virtualization. In particular, regarding the virtualization in desktop, it is one of the most widely used technology at the present time. Because it is able to efficiently use various types of operating systems in a physical computer. A virtual machine image that is a key component of virtualization is difficult to investigate. because the structure of virtual machine image is different from hard disk image. Therefore, we need researches about appropriate investigation procedure and method based on technical understanding of a virtual machine. In this research, we suggest a procedure of investigation on a virtual machine image and a method for a corrupted image of the VMware Workstation that has the largest number of users.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1507-1518
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• 2020

High-quality images have a lot of information, so sensitive data is stored by encryption for private company, military etc. Encrypted images can only be decrypted with a secret key, but the original data cannot be retained when attacked by the Shear attack and Noise pollution attack techniques that overwrite some pixel data with arbitrary values. Important data is the more necessary a countermeasure for the recovery method against attack. In this paper, we propose a random number generator PingPong256 and a shuffling method that rearranges pixels to resist Shear attack and Noise pollution attack techniques so that image and video encryption can be performed more quickly. Next, the proposed PingPong256 was examined with SP800-22, tested for immunity to various noises, and verified whether the image to which the shuffling method was applied satisfies the Anti-shear attack and the Anti-noise pollution attack.

• Journal of Animal Science and Technology
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• v.63 no.1
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• pp.1-15
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• 2021

As a result of intensive breeding, litter size has considerably increased in pig production over the last three decades. This has resulted in an increase in farrowing complications. Prolonged farrowing will shorten the window for suckling colostrum and reduce the chances for high-quality colostrum intake. Studies also agree that increasing litter sizes concomitantly resulted in decreased piglet birth weight and increased within-litter birth weight variations. Birth weight, however, is one of the critical factors affecting the prognosis of colostrum intake, and piglet growth, welfare, and survival. Litters of uneven birth weight distribution will suffer and lead to increased piglet mortality before weaning. The proper management is key to handle the situation. Feeding strategies before farrowing, management routines during parturition (e.g., drying and moving piglets to the udder and cross-fostering) and feeding an energy source to piglets after birth may be beneficial management tools with large litters. Insulin-like growth factor 1 (IGF-1)-driven recovery from energy losses during lactation appears critical for supporting follicle development, the viability of oocytes and embryos, and, eventually, litter uniformity. This paper explores certain management routines for neonatal piglets that can lead to the optimization of their colostrum intake and thereby their survival in large litters. In addition, this paper reviews the evidence concerning nutritional factors, particularly lactation feeding that may reduce the loss of sow body reserves, affecting the growth of the next oocyte generation. In conclusion, decreasing birth weight and compromised immunity are subjects warranting investigation in the search for novel management tools. Furthermore, to increase litter uniformity, more focus should be placed on nutritional factors that affect IGF-1-driven follicle development before ovulation.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.155-161
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• 2022

The outbreak of the Covid 19 increased the interest on the 'Virtual Tourism. In this research the key word related to "Virtual Tourism" was collected through the search engine and was analyzed through the data mining method such as Log-odds ratio, Frequency, and network analysis. It is clear that the information and communication dependency increased in the field of "Virtual Tourism" after Covid 19 and also the trend have changed from "securement of the contents diversity" to "project related to economic recovery." Since the demands for the "Virtual Reality" such as metaverse is increasing, there should be an economic and circular structure in which the government establishing a related policy and the funding plan based on the research, local government and the private companies planning and producing discriminate contents focusing on AISAS(Attension, Interest, Search, Action, Share) aand the research institutions and universities developing, applying, assessing and commercializing the technology.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.617-624
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• 2022

The small electric vehicles equipped with V2X(vehicle to everything) systems may provide more information and function to the existing navigation system of the vehicle. The key components of V2X technology include V2V (vehicle to vehicle), V2N(vehicle to network) and V2I (vehicle to infrastructure). This study is to design and implementation of VI type E-PTO which is interfaced with external equipments, the work designs the components of E-PTO such as DC/DC converter, DC/AC converter, battery bidirectional charging system etc. Also, it implements the devices and control systems for driving. The test results of VI type E-PTO components showed allowable 10% requirements of transient voltage variation rate and recovery time within 100ms for start/stop and normal operation.