• Steel and Composite Structures
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• v.30 no.5
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• pp.483-492
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• 2019

In the current study, the influence of the initial lateral (sweep) shape and the cross-sectional twist imperfection on the lateral torsional buckling (LTB) response of doubly-symmetric steel I-beams was investigated. The material imperfection (residual stress) was not considered. For this objective, standard European IPN 300 beam with different unbraced span was numerically analyzed for three imperfection cases: (i) no sweep and no twist (perfect); (ii) three different shapes of global sweep (half-sine, full-sine and full-parabola between the end supports); and (iii) the combination of three different sweeps with initial sinusoidal twist along the beam. The first comparison was done between the results of numerical analyses (FEM) and both a theoretical solution and the code lateral torsional buckling formulations (EC3 and AISC-LRFD). These results with no imperfection effects were then separately compared with three different shapes of global sweep and the presence of initial twist in these sweep shapes. Besides, the effects of the shapes of initial global sweep and the inclusion of sinusoidal twist on the critical buckling load of the beams were investigated to unveil which parameter was considerably effective on LTB response. The most compatible outcomes for the perfect beams was obtained from the AISC-LRFD formulation; however, the EC-3 formulation estimated the $P_{cr}$ load conservatively. The high difference from the EC-3 formulation was predicted to directly originate from the initial imperfection reduction factor and high safety factor in its formulation. Due to no consideration of geometric imperfection in the AISC-LFRD code solution and the theoretical formulation, the need to develop a practical imperfection reduction factor for AISC-LRFD and theoretical formulation was underlined. Initial imperfections were obtained to be more influential on the buckling load, as the unbraced length of a beam approached to the elastic limit unbraced length ($L_r$). Mode-compatible initial imperfection shapes should be taken into account in the design and analysis stages of the I-beam to properly estimate the geometric imperfection influence on the $P_{cr}$ load. Sweep and sweep-twist imperfections led to 10% and 15% decrease in the $P_{cr}$ load, respectively, thus; well-estimated sweep and twist imperfections should considered in the LTB of doubly-symmetric steel I-beams.

• Journal of Korean Academy of Nursing
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• v.49 no.3
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• pp.317-328
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• 2019

Purpose: The purpose of this study was to identify the effect of ghrelin on memory impairment in a rat model of vascular dementia induced by chronic cerebral hypoperfusion. Methods: Randomized controlled groups and the posttest design were used. We established the representative animal model of vascular dementia caused by bilateral common carotid artery occlusion and administered $80{\mu}g/kg$ ghrelin intraperitoneally for 4 weeks. First, behavioral studies were performed to evaluate spatial memory. Second, we used molecular biology techniques to determine whether ghrelin ameliorates the damage to the structure and function of the white matter and hippocampus, which are crucial to learning and memory. Results: Ghrelin improved the spatial memory impairment in the Y-maze and Morris water maze test. In the white matter, demyelination and atrophy of the corpus callosum were significantly decreased in the ghrelin-treated group. In the hippocampus, ghrelin increased the length of hippocampal microvessels and reduced the microvessels pathology. Further, we confirmed angiogenesis enhancement through the fact that ghrelin treatment increased vascular endothelial growth factor (VEGF)-related protein levels, which are the most powerful mediators of angiogenesis in the hippocampus. Conclusion: We found that ghrelin affected the damaged myelin sheaths and microvessels by increasing angiogenesis, which then led to neuroprotection and improved memory function. We suggest that further studies continue to accumulate evidence of the effect of ghrelin. Further, we believe that the development of therapeutic interventions that increase ghrelin may contribute to memory improvement in patients with vascular dementia.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.121-132
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• 2019

Purpose: This study aims to analyze the meaning of architectural space of Alvar Aalto, which is based on architectural theories of periodic flows and the form of the space with the various elements applied to the works. Method: It analyzes the interrelationships of light, form and material in triangular composition by synthesizing the architectural vocabulary of Alvar Aalto from the viewpoint of modernism. Results: The architectural works of Alvar Aalto are centered on the combination of light, form, material, and space diversity, emphasizing social awareness and linking the human scale with the building environment. Conclusion: The structure of the Alvar Aalto is a synonym of nature and culture, society and individuals, standardization and diversity, universality and locality, intellectual and emotional, scientific and human psychological. It is possible to apply reciprocity elements to architectural spaces in a comprehensive manner while being different from each other in terms of rationality and immediacy.

• Archives of Plastic Surgery
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• v.46 no.1
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• pp.16-22
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• 2019

Background Various surgical techniques have been used to correct Tessier number 7 craniofacial cleft, which involves macrostomia, ear deformity, and hemifacial microsomia. To achieve symmetrical and satisfactory results in patients with macrostomia, the authors performed a 1-mm medial overcorrection on the cleft side and evaluated the results of this procedure. Methods A retrospective medical record review of patients diagnosed with Tessier number 7 craniofacial cleft from March 1999 to February 2017 was performed. Using clinical photographs, outpatient clinic records, and operative records, information was recorded regarding concurrent congenital anomalies, postoperative complications, and follow-up. Using Photoshop CS2, the length of both sides of the lip was compared. The ratio of these lengths was calculated to evaluate lip symmetry. Results Of the patients treated at the Department of Plastic and Reconstructive Surgery at Kyungpook National University Chilgok Hospital, 11 (male-to-female sex ratio, 7:4) were diagnosed with Tessier number 7 craniofacial cleft. Concurrent congenital anomalies included skin tag, hemifacial microsomia, and cleft palate. The mean duration of follow-up was $78.273{\pm}72.219$ months and the mean ratio of the lengths of both sides of the lip was $1.048{\pm}0.071$. Scar widening occurred as a postoperative complication in some patients. No cases of wound infection, bleeding, or wound dehiscence occurred. Conclusions For the successful correction of macrostomia, plastic surgeons should consider both functional and aesthetic problems of the lip. Adequate repair of the orbicularis oris muscle, skin closure with Z-plasty, and medial overcorrection of the neo-oral commissure led to good results in our patients.

• International Journal of Computer Science & Network Security
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• v.21 no.4
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• pp.178-185
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• 2021

The emergence of social networks has led to the flourishing of a new golden era of branding, which is a challenge for companies due to the need for creative positioning of companies with an emphasis on building trust and loyalty to the brand. Consumers are becoming more demanding and due to a wide range of products in different markets, make demands that are more stringent on companies. The goal of this article was to study the main trends of branding and advertising on social networks to develop a new approach to brand promotion. Methodology. The quantitative and qualitative research design was used to determine the main trends in branding and advertising on social networks. The methodology included the following methods: 1) analysis of the relationship between brand value and brand content strategy, 2) content analysis of the content of companies in social networks on the example of 10 world-famous brands with the highest value. The results allowed forming the criteria of effective content and communication: simplicity of content and simplicity of communication, lack of direct advertising of products, emphasis on global socio-economic problems and social orientation, unobtrusive communication, content creativity, indirect information about the product or work, the history of the company's development through various tools. The main content strategies of brands are defined: storytelling strategy; strategy of informing about the history of the company's development; entertainment and information strategy; strategy of joint interaction with the audience through the involvement of wellknown influencers or users of products. The theoretical and practical value of the results is confirmed by the conceptualization of the main content strategies of world-famous brands, which are pioneers in new ways to build relationships with users through social networks. The research proposes to use a customer-oriented approach to brand promotion. This means studying consumer behavior and predicting possible changes in behavior, which determines the level of interaction with the brand, the content strategy of the brand, and its effectiveness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.123-130
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• 2021

With the recent developments in computer technology, there has been an increasing interest in the field of machine learning. This also has led to a significant increase in real business cases of machine learning theory in various sectors. In finance, it has been a major challenge to predict the future value of financial products. Since the 1980s, the finance industry has relied on technical and fundamental analysis for this prediction. For future value prediction models using machine learning, model design is of paramount importance to respond to market variables. Therefore, this paper quantitatively predicts the stock price movements of individual stocks listed on the KOSPI market using machine learning techniques; specifically, the reinforcement learning model. The DQN and A2C algorithms proposed by Google Deep Mind in 2013 are used for the reinforcement learning and they are applied to the stock trading strategies. In addition, through experiments, an input value to increase the cumulative profit is selected and its superiority is verified by comparison with comparative algorithms.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.9
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• pp.117-128
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• 2018

The United States understood the fostering of pro-U.S. elites in "free world" countries as an important Cold War weapon. From 1954 to 1962, the U.S provided considerable assistance to Seoul National University (SNU) for its postwar rehabilitation and future development in terms of repair and construction of campus buildings, equipment and book purchases, and faculty exchanges. With the aid of this educational assistance project widely known as the Minnesota Project, SNU was reborn with an academic orientation to the U.S., separating itself from the Japanese education that was its origin. This study argues that the Minnesota Project played an important role in crafting SNU's architecture program and the exchange program's recipients as key "knowledge brokers." For individual trainees, experience in the U.S., as opposed to a backwards situation in their homeland, had allowed them to recognize the U.S. as an ideal source of knowledge. Since the Minnesota Project, SNU's Architectural Engineering Department was filled with faculty members who had trained or studied in the U.S., which became a significant distinction of SNU's architecture program in sharp contrast to its counterparts at Hanyang University and Hongik University where most of the faculty members studied in Japan during the Japanese colonial period. As many graduates of SNU had been appointed as faculty members in newly-founded architecture programs in South Korea, a hierarchical diffusion path had emerged in architectural education that led from SNU to other school's architecture programs, with the U.S. at the apex. The legacy of the Minnesota Project extended over the next few decades, in which studying architecture in the U.S. was recognized as a shortcut to success in the field.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.11
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• pp.135-144
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• 2018

During the Late Joseon dynasty, abandoned mountain fortresses were urgently repaired for the operation of foothold mountain fortresses in Gyeongsang-do, during the Japanese Invasion of Korea in 1592 and immediately after the Qing Invasion of Korea in 1636. Immediately after the Qing Invasion of Korea, an external fortress wall was built and added to each of Cheonsaeng Fortress and Geumo Fortress to establish a system of protecting locals inside a fortress at important locations for border defense against Japan in the Yeongnam region. Cheonseng Fortress, however, did not have sufficient geographical and protection conditions as a mountain fortress for protecting people inside it; thus, Gasan Fortress was newly built to replace Cheonsaeng Fortress. Geumo and Gasan Fortresses were used in border defense against Japan during the period from King Injo's reign to the end of Joseon Dynasty, because the fortresses served the purpose of defending Nakdonggang River and middle roads located at important roads along the border in the Yeongnam region and because it was possible to quickly repair and use their existing fortress walls and internal facilities, such as middle fortress walls and ponds, that were constructed for long-term protection of locals inside the fortress. In addition, it was found, in this study, that a continuous discussion on how to supplement fortresses led to the reinforcement and improvement of fortress facilities and fortification technology through the application of major strengths of Chinese (Ming) and Japanese fortress systems.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.93-98
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• 2019

Recently, the rise in the housing burden on young couples has led to a serious housing poverty among young people. The number of young people who move into public rental housing is very small because the eligibility for public rental housing is determined based on income, the status of housing subscription, and the size of the household. With this background, the government launched a public rental housing program called Happy Housing Project, which gives young people the priority to move in first. However, the program is facing an obstacle due to the opposition of local residents. The purpose of this paper is to examine whether public rental housing can induce the NIMBY syndrome through conducting a literature review, followed by an analysis of NIMBY syndrome around the currently supplied Happy House development areas, and finally analyzing the household characteristics in order to identify which households were prone to the NIMBY syndrome. To confirm the existence of the NIMBY syndrome, this paper comparatively analyzed the two groups using binary logit analysis. The first group consists of households that are against the Happy House policy, and the second group consists of households that are aware of the Happy House development taking place in their neighborhoods, and are against the development. This study considered the households against the Happy House development in their neighborhoods to have NIMBY tendencies, and focused on comparing the households with NIMBY tendencies with those who do not. To confirm whether the residents around the Happy House neighborhoods have NIMBY tendencies, this paper compared the two groups and confirmed that about 4% of the households have NIMBY tendencies. This paper subsequently analyzed the households with NIMBY tendencies, and found them to have a higher number of children, reside in apartments and reside in owned homes. The volume of the 2018 Happy Housing (35,000 households) is three times higher than that of 2017. The present study aims to analyze the tendency of residents who oppose the construction of Happy Housing so as to derive policy implications for the smooth provision of public rental housing.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.8
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• pp.89-100
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• 2019

The purpose of this study is to critically review the repair works of Seokguram architecture and to search for its original form and space. Seokguram's architectural form has been transformed throughout three repair works. The first transformation occurred during the repair work of the Colonial Government in 1913-1915, and the second occurred during the repair work of the Colonial Government in 1920-1923. The repair work done by the Korean Government in 1961-1964 also caused a severe change in the architectural form and space of Seokguram architecture. The more the repair work was added to Seokguram, the more its original form flew away like a mirage. Through the three repair works, the spatial composition of Seokguram changed in the following directions: from ((front chamber + passageway) + main chamber) to (front chamber + (passageway + main chamber)) through the second repair work, from (front chamber + (passageway + main chamber)) to (front chamber + passageway + main chamber) through the last repair work. Although the compositional space hierarchy of Seokguram was maintained during the first repair work, the architectural form based on the dry method was changed to the form based on the wet method. The Korean government's repair work was a tragedy for the 'Seokguram conservation project' that the people who led the conservation process misunderstood the architectural nature of Seokguram.