• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.1
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• pp.33-47
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• 2015

Concrete lining in tunnel construction is used as secondary support for downward loads when primary support decays. The use of concrete lining varies greatly depending on the intentions of engineer and/or client. An engineer uses much smaller deformation modulus which determines the concrete lining thickness than of a pattern 3, when supporting patterns 4 and 5 are used in a weathered rock and soil. Considering these conditions, this study intends to suggest optimal construction procedures through a back analysis using a computer program(MIDAS-civil). Cases of Seoul Subway System line${\bigcirc}{\bigcirc}$ zone${\bigcirc}{\bigcirc}$ were selected to be examined for this study. The results show that it is possible to reduce the thickness of concrete lining. When results from this study were applied to Seoul Metropolitan subway construction projects, it is expected to bring economic benefits.

• STI Policy Review
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• v.5 no.2
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• pp.1-19
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• 2014

The concept of a holistic innovation policy is defined in this article, with discussions of what it is, why it is relevant, and how it can be implemented to enhance product innovation. It is shown that the innovation systems approach has diffused rapidly during the latest decades and has completely replaced the linear view in the field of innovation research. The majority of European countries are striving in the direction of developing a more holistic innovation policy. However, it is concluded that the innovation policies in European countries are still dominantly linear despite the fact that holistic policy seems to be the driving vision. Innovation policy is behindhand. Why innovation policy is still linear is also preliminarily discussed. Policymakers attending conferences on innovation are practically always in favor of holistic (systemic, broad-based, comprehensive, etc) innovation policies, have abandoned the linear view by learning from innovation research. The division between "linear" and "holistic" seems to be located within the community where innovation policies are designed and implemented, a community composed of policymakers (administrators/bureaucrats) and elected politicians. Perhaps the dividing line is between these two groups in that politicians, who actually make the decisions, may still reflexively believe in the linear view. Nevertheless, there seems to be a failure in communication between researchers and politicians in the field of innovation and there is therefore a strong need to involve innovation researchers in policy design and implementation to a much higher degree. Another way to increase the degree of holism could be to separate innovation policy from research policy, since their integration tends to cement the linear character of innovation policy. The empirical results are based on a questionnaire sent to twenty-three EU Member States, out of which nineteen (83%) responded. Part of the work for this article was carried out for the European Research and Innovation Area Committee (ERAC) of the European Commission (DG RTD).

• Journal of Rhinology
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• v.25 no.2
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• pp.103-107
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• 2018

Pregnancy rhinitis is a relatively common condition. It is characterized by the presence of nasal symptoms, especially nasal congestion, not present prior to pregnancy, but typically present during the last 6 or more weeks of pregnancy, without other signs of respiratory tract infection or any known allergic causes, and disappearing completely within 2 weeks after delivery. Nasal saline irrigation, intranasal steroid spray, and oral antihistamines are usually recommended as the first line of treatment for rhinitis. However, most pregnant women refuse medical treatment for pregnancy rhinitis because of the fear of teratogenicity. Severe pregnancy rhinitis increases the risk of snoring, which has been suggested as having adverse effects on the fetus. In cases where the patients are unable to control their symptoms, pregnancy rhinitis can negatively affect the quality of life (QOL) as well as the pregnancy outcome. Therefore, special caution is required for determining the appropriate diagnosis and treatment modalities for pregnancy rhinitis. Here, we report for the first time, the successful treatment of pregnancy rhinitis that was unresponsive to conservative management and medical therapy by using microdebrider-assisted inferior turbinoplasty at the final stages of pregnancy, along with a review of the relevant literature.

• International Area Studies Review
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• v.16 no.1
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• pp.3-27
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• 2012

This paper adopts recently developed panel unit root test that is cross-sectionally robust. Cointegration test is also used to find whether regional house prices are in line with gross regional domestic production (GRDP) in the long run in Korea during 1989-2009. Based on the panel VECM and the panel ARDL models, we examine causal relationships among the variables and estimate the long-run elasticity. We find evidence of cointegration and bidirectional causal relationships between regional house prices and GRDP. The results of long-run estimates, using both fixed effect and ARDL models, show that house prices positively and significantly influence on the GRDP and vice versa. Together with these results, the findings of ARDL-ECM imply that there exists a long-run equilibrium relationship between house prices and regional economic variables even if there is a possibility of short-run deviation from its long-run path.

• International Area Studies Review
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• v.13 no.2
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• pp.505-523
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• 2009

We study the cost of capital of Islamic enterprise using the Capital Asset Pricing Model(CAPM). When there exists no risk-free interest rate, the security market line(SML) of Islamic enterprise shows an upward slope starting from the origin. The slope is bigger than that of SML with risk-free interest rate. This is because the cost of capital of Islamic enterprise is higher than that of western firms for the same level of systematic risk. When the effect of zakat is considered, the risk-free interest rate is replaced by minimum required rate of return. The SML of Islamic enterprise reveals an upward slope but it does not pass through the origin. This is because Islamic enterprise cannot invest on risk-free asset. In order to overcome the theoretic limits of CAPM, we propose to use multi-factor approach such as arbitrage pricing model instead of single-factor model for future study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.723-730
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• 2006

Recently, The flexible moving block system in train operation has been introduced to the worldwide rail transportation markets. This paper is a comparative study of the conventional fixed block systems effects and the flexible moving block system on train operating time saving. Based on the literature review, the new algorithm is developed. It is to calculate the optimum headway time of the train. The proposed algorithm can overcome some of the existing algorithm problems, such as the limits of the data and unaware of the rail characteristic. The total travel time saving effect has been analyzed by applying the skip stop scheduling system to the each block system. The results of this study indicated that the total travel time is approximately 40% decreased and the schedule velocity is approximately 24% improved when the moving block system is applied. The results of this study could be used as a theoretical basis for the selection of rail signal system in Seoul's subway number 2 line.

• International Area Studies Review
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• v.13 no.1
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• pp.309-340
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• 2009

Multinational Corporations (MNCs) are increasingly establishing globally-distributed R&D (Research and Development) centers in which sites around the world work collaboratively to develop new manufacturing and product technologies. Following new globalization strategies, these projects more often include sites in Emerging/Newly Industrializing Economies (E/NIEs). The success of these ventures promises to be increasingly important both for the bottom line of MNCs and for the development ambitions of E/NIEs. This study attempts to identify these trends and to compare R&D transfer between Korea and China. The study identifies specific factors on MNC's R&D transfer and compares those operating factors between the R&D centers in Korea and China, which attract many MNCs in the world. Among those eight dimensions relating to MNCs' operation, there are significant differences in site selection, market characteristics, government support, and R&D networking between Korea and China. The analysis show more positive factors on China than Korea regarding R&D operations. The result will be helpful for both MNC's managers and governments' decision makers with respect to R&D transfer.

• Korea Trade Review
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• v.46 no.4
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• pp.189-204
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• 2021

The fourth industrial revolution is affecting the industry as a whole, and the current logistics industry is coexisting with crises and opportunities. As part of overcoming this situation, the online platformization of the logistics market has recently been rapidly taking place, and the growth of e-commerce around developed countries has emerged as a demand for flexible freight services that can send and receive cargo anywhere and anytime at appropriate cost. However, the logistics industry has not been able to change rapidly in line with the demands of the market as it is immersed in traditional transportation transactions. Thus, the digital transformation of the freight market has become urgent to address problems such as uncertainty over traditionally closed and conservative freight market transaction processes and the lack of reliability caused by information asymmetry. Therefore, innovative domestic and foreign companies are attempting to establish a new way of transporting cargo, especially a marketplace way of connecting suppliers and consumers. Current status analysis and case studies were conducted through existing literature surveys, and prior research on freight market place selection factors was previewed, and the selection factors were stratified into five upper and 19 lower factors. Through this study, it is expected that improvements for sustainable growth of freight marketplace companies will be derived and that it will be a basic study of establishing management strategies through marketplace operation and quality control. In addition, it is deemed that the priority of customer requirements can be actively accepted, providing an opportunity to actively respond and strengthen corporate competitiveness.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.85-96
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• 2024

Objective: Congenital intracranial pial arteriovenous fistula (PAVF) is a rare cerebral vascular pathology characterized by a direct shunt between one or more pial feeding arteries and a cortical draining vein. Transarterial endovascular embolization (TAE) is widely considered first line therapy. Curative TAE may not be achievable in the multi-hole variant due to the potential to harbor innumerable small feeding arteries. Transvenous embolization (TVE) may be considered to target the final common outlet of the lesion. Here, we present a series of four patients with complex multi-hole congenital PAVF treated with staged TAE followed by TVE. Methods: A retrospective review was conducted on patients who underwent treatment for congenital, multi-hole PAVFs treated by a combined TAE/TVE approach at our institution since 2013. Results: We identified four patients with multi-hole PAVF treated by a combined TAE/TVE. Median age was 5.2 (0-14.7) years. Median follow-up of 8 (1-15) months by catheter angiography and 38 (23-53) months by MRI/MRA was obtained. TVE achieved complete occlusion in three patients that proved durable on radiographic follow-up and demonstrated excellent clinical outcomes with a modified Rankin Score (mRS) of 0 or 1. Complete occlusion of the draining vein was not achieved by TVE in one case. This patient is graded as pediatric mRS=5 three years post-procedure. Conclusions: With thorough technical considerations, our series indicates that TVE of multi-hole PAVF that are refractory to TAE is feasible and effective in arresting the consequences of chronic, high-flow AV shunting produced by this pathology.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.279-291
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• 2024

Objective: This was to develop headforms for the labor population, based on a three-dimensional(3D) face dimensions data base(DB) and a principal component analysis(PCA) fit test panel, in selection, use and maintenance of respirators in Korea. Methods: This study was part of a two-year-project initiated in 2021. The study was designed and conducted in line with ISO 16976-2 while subjects were those employed in the development of the PCA fit test panel. The approaches included literature review; examination on conformity of the 3D face dimensions DB; and development of headforms representing the labor population. The mean data were used in order to construct each model of the headforms through a way of 3D modeling and 3D printing technology. Results: A total of 2,752 subjects were determined. Five models of headforms(small, medium, large, long-narrow, short-wide) were completely constructed for the labor population. For example, means of the 10 face dimensions for medium headform model were: minimum frontal breadth 106 mm, face width 136 mm, jaw width 127 mm, face length 111 mm, interpupillary distance 69 mm, head breadth 164 mm, nose protrusion 12 mm, nose breadth 34 mm, nasal root breadth 35 mm, and nose length 50 mm. Conclusions: Five models of headforms were newly constructed using the study data. It is likely desirable that the constructed headforms, together with the 3D face dimensions DB as well as the PCA fit test panel, can be utilized more effectively in selection, use and maintenance of respirators for users including the labor population.