• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.305-313
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• 2020

The use of cable tunnels for electric power transmission as well as their construction in difficult conditions such as in subsea terrains and large overburden areas has increased. So, in order to efficiently operate the small diameter shield TBM (Tunnel Boring Machine), the estimation of advance rate and development of a design model is necessary. However, due to limited scope of survey and face mapping, it is very difficult to match the rock mass characteristics and TBM operational data in order to achieve their mutual relationships and to develop an advance rate model. Also, the working mechanism of previously utilized linear cutting machine is slightly different than the real excavation mechanism owing to the penetration of a number of disc cutters taking place at the same time in the rock mass in conjunction with rotation of the cutterhead. So, in order to suggest the advance rate and machine design models for small diameter TBMs, an EPB (Earth Pressure Balance) shield TBM having 3.54 m diameter cutterhead was manufactured and 19 cases of full-scale tunneling tests were performed each in 87.5 ㎥ volume of artificial rock mass. The relationships between advance rate and machine data were effectively analyzed by performing the tests in homogeneous rock mass with 70 MPa uniaxial compressive strength according to the TBM operational parameters such as thrust force and RPM of cutterhead. The utilization of the recorded penetration depth and torque values in the development of models is more accurate and realistic since they were derived through real excavation mechanism. The relationships between normal force on single disc cutter and penetration depth as well as between normal force and rolling force were suggested in this study. The prediction of advance rate and design of TBM can be performed in rock mass having 70 MPa strength using these relationships. An effort was made to improve the application of the developed model by applying the FPI (Field Penetration Index) concept which can overcome the limitation of 100% RQD (Rock Quality Designation) in artificial rock mass.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.2
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• pp.93-101
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• 1999

A simple experimental method was used in an attempt to realize the elevation of the fishing ability of purse seine in the sea area of Cheju Island, the changes of seine volume and tension in the purseline during pursing. Experiments carried out on the six types simplified reduced model seines which were made of knotless nettings. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two-ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cmfor seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. These model purse seines were made of the scale of 1/200 of its full scale, a 120 ton in the near sea of Cheju Island. Designing and testing for the model purse seines were based on the Tauti's law. Experiments were measured in the observation channel of a flume tank at the static conditions set up shooting and pursing equipments. Motion of purse seine during purse line was recorded by the two sets video camera for VTR which were placed in top and front of the model seine. The reading coordinate of seine volume carried out by the video digitization system, disk data for the purseline tension. An analysis were performed on the changes seine volume and tension in the purseline during pursing. The results obtained were as follows: 1. The seine volume during pursing was largest for Ⅵ seine with smallest d/l followed by V, IV, III, II and I seines, and tension in the purseline was small. 2. Seine volume during pursing can be expressed by the following equation; CVt=l-EXP[｛2.79 (d/l）＋0.35｝t-33.37 (d/l) ＋ 0.57] Where CVt is volume ratio, d is twine diameter, l is leg length and t is pursing time (sec). 3. Tension in the purse line during pursing can be expressed by the following equation; T= 1- EXP ｛0.57t ＋ 13.36 (d/l)+2.97｝ Where T is tension (kg) in the purseline during pursing.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.2
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• pp.73-88
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• 2009

Objectives : Neuronal changes that result from treadmill exercise for patients with Parkinson's disease(PD) have not been well documented, although some clinical and laboratory reports suggest that regular exercise may produce a neuroprotective effect and restore dopaminergic and motor functions. However, it is not clear if the improvements are due to neuronal alterations within the affected nigrostriatal region or result from a more general effect of exercise on affect areas and motivation. In this study, we demonstrate that motorized treadmill exercise improves the neuronal outcomes in rodent models of PD. Methods : We used a chronic mouse model of parkinsonism, which was induced by injecting male C57BL/6 mice with 10 doses(Every 12 hour) of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (30 mg/kg) and probenecid (20 mg/kg) over 5 days. These mice were able to sustain an exercise training program on a motorized rodent treadmill at a speed of 18 m/min, $0^{\circ}$ of inclination, 40 min/day, 5 days/week for 4 weeks. At the end of exercise training, we extracted the brain and compared their neuronal and neurochemical changes with the control(saline and sedentary) mice groups. Synphilin protein is the substance that manifestly reacts with ${\alpha}$-synuclein. In this study, we used Synphilin as a manifest sign of recovery from neurodegeneration. We analyze the brain stems of the substantia nigra and striatum region using the western blotting technique. Results : There were no expression of synphilin in the saline-induced groups. The addition of MPTP(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) greatly accelerated synphilin expression which meant an aggregation of ${\alpha}$-synuclein. But, the MPTP-induced treadmill exercise group showed significantly lower expression than the MPTP-induced sedentary group. This means treadmill exercise has a definite effect on the decrease of ${\alpha}$-synuclein aggregation. Conclusions : In this study, our results suggest that treadmill exercise promoted the removal of the aggregation of ${\alpha}$-synuclein, resulting in protection against disease development and blocks the apoptotic process in the chronic parkinsonian mice brain with severe neurodegeneration.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.4
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• pp.1-20
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• 2023

This study attempted to identify the relationship between the investment determinants of accelerators and investment performance through empirical analysis. Through literature review, four dimensions and 12 measurement items were extracted for investment determinants, which are independent variables, and investment performance was adjusted to the cumulative amount of subsequent investment based on previous studies. Performance data from 594 companies selected by TIPS from 2017 to 2019, which are relatively reliable and easy to secure data, were collected, and the subsequent investment cumulative attraction amount, which is a dependent variable, was hypothesized through multiple regression analysis three years after the investment. As a result of the study, 'industrial experience years' in the characteristics of founders, 'market size', 'market growth', 'competitive strength', and 'number of patents' in the characteristics of products and services had a significant positive (+) effect. The impact of independent variables on dependent variables was most influenced by the competitive strength of market characteristics, followed by the number of years of industrial experience, the number of patents, the size of the market, and market growth. This was different from the results of previous studies conducted mainly on qualitative research methods, and in most previous studies, the characteristics of founders were the most important, but the empirical analysis results were market characteristics. As a sub-factor, the intensity of competition, which was the subordinate to the importance of previous studies, had the greatest influence in empirical analysis. The academic significance of this study is that it presented a specific methodology to collect and build 594 empirical samples in the absence of empirical research on accelerator investment determinants, and created an opportunity to expand the theoretical discussion of investment determinants through causal research. In practice, the information asymmetry and uncertainty of startups that accelerators have can help them make effective investment decisions by establishing a systematic model of experience-dependent investment determinants.

• Information Systems Review
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• v.10 no.3
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• pp.89-109
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• 2008

Korean card firms suffered harsh setbacks due to high credit defaults in 2002 and 2003, after issuing cards recklessly. Their key principle is changed to grow without damaging profitability and financial soundness. However, competition in the credit card market is heating up rapidly. Bank-affiliated card firms, having stronger sales networks and more capital than independent issuers, have increased their investments in card affiliates in a bid to develop new cash cows. Moreover, newly emerging independent card firms have waged fiercer campaigns to raise their credit card market share. In order to overcome these business conditions, S-card has settled on a strategy that focuses on stepping up marketing aimed at increasing charge card spending rather than credit card loans or cash lending services. Accordingly, S-card reformed the current business classification system of merchants, which was out-of-dated and originally built for the purpose of deciding merchant service fees only. They also drove customer segmentation planning to deliver the right customers to the right merchants. In this paper, we emphasize the problems of business classification systems of merchants with which most credit card firms have faced, and the need for reforming them not only to provide customer-tailored services but also to raise their business promotion excellence by reviewing S-card's process of customer segmentation.

• Journal of the Korean association of regional geographers
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• v.21 no.3
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• pp.450-460
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• 2015

Metropolitan-wide economic region policy which was enforced by Lee Myeongbak government was a timely policy at least to Dongnam region. However, examining the activities and outcomes of Dongnam Regional Development Committee, there are many doubts about the policy as metropolitan-wide governance. Dongnam Regional Development Committee had many operational problems. It had few independent labor force and low budget. Also its authority was limited. Above all, its purpose and function was unclear. As a result, the policy was abolished as new government suceeded. Henceforth Dongnam region needs metropolitan-wide governance for metropolitan-wide economic development. If an organization which supports industrial and regional development of Dongnam region would be reestablished, the orientation of governance has to be determined. In this case, the main function of the organization would be researching about Dongnam metropolitan-wide economic region, and suggesting and recommending metropolitanwide development strategy. For the benchmark of the organization, Metropolitan Planning Organization of the US, Joint Venture at Silicon Valley and Regio Randstad of the Netherlands would be appropriate. Above organizations receive budgets from central and regional government and private sector. They research about regional economics and urban development which is comprehensive and metropolitan-wide and could not be done by local government alone.

• Journal of Korea Technology Innovation Society
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• v.19 no.1
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• pp.105-136
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• 2016

This paper analyzed the qualitative evaluation indicators of the SYSTEM sector of the LINC program, which aimed at strengthening ability of regional universities through the activities of industry-academia cooperation (IAC). By using interview data and the program reports of universities, this research explored the problems of the indicators and suggested improvement measures which could lead to performance creativity. According to research results, in university system reform for activating IAC, some improvements are required as follows: limiting excessive expansion of IAC-friendly faculty evaluation; and evaluating soft aspects in the reform of academic affairs. In relation to strengthening of ability of the IAC organization, the indicators need to be amended as follows: enhancing the role of channel of IAC Foundation; strengthening the function of planning team of the IAC Foundation; and inducing development of own model of universities for IAC. As regards expansion of IAC infrastructure, it is necessary to enlarge the manpower who can develop programs of the support center in the foundation and to secure of operators for effective operation of joint-using equipments. Therefore, the indicators are required to be upgraded, considering these improvement direction.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.68-80
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• 2001

While opportunities for international construction firms have been growing with globalization, the risk of international construction projects is significantly increasing in severity and complexity. However, the traditional risk management approach in the construction industry has maintained a profit focus. In addition, this approach has not considered the overall risk at the corporate level, but rather has focused only on the risk of individuals at the project level. Corporate risk management should be implemented from the initial stages of new project selection. This paper suggests the Multi-criteria Integrated Systematic Analysis as a strategic decision-making tool for international construction contractors. The model integrates the multi-criteria of risk, return, and efficiency to choose the optimal set of new portfolios at the corporate level. This model also introduces the Value at Risk (VaR) concept to the international construction industry to present the total risk at the corporate level. To validate this model, this paper tested an experimental case study using the historical data of a global general contractor.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.715-722
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• 2020

This paper proposes a design verification method based on system dynamics for offshore separation systems. Oil and gas separation systems are key components of offshore oil platforms; these systems determine the competitiveness of engineering, procurement, and construction (EPC) projects, especially in terms of added value. However, previous research on design verification has been limited to the process and deliverables of design. To address this, the study aims to develop a comprehensive design verification method and the associated functions from the perspective of project management, for the entire project life-cycle of offshore structures. The proposed methodology for design verification is expected to contribute toward effective and detailed designs as well as improve the competitiveness of EPC companies in constructing of shore structures during the early design stages. We first analyzed the separation system of the FPSO using the design verification method adopted by advanced countries and compared it with the system dynamics process formalized as ISO 15288. Subsequently, a tailored process for the design verification of the offshore structure was derived. It is shown that the proposed design verification method can be applied to the front-end engineering design process of of shore structures. Moreover, it can contribute toward the successful performance of offshore projects in the future and also minimize design changes and critical risks during the construction of these offshore structures.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.269-278
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• 2016

In order to improve air quality in the Seoul Metropolitan Area (SMA), the "Special Act on Seoul Metropolitan Air Quality Improvement" has been enforced since 2005. The strategy has resulted in some reduction of air pollution, but there has not been much research into the quantitative impact analysis of each separate preventive countermeasure. Therefore, we analyzed nitrogen oxide reduction resulting from implementation of the emission control plan for on-road mobile sources. The MM5-SMOKE-CMAQ model system was employed for air quality prediction. Reduced $NO_x$ emissions for SMA was 16,561 ton, 4.7% of reduction rate, in 2007. One countermeasure, tighter acceptable standards for manufacturing vehicles, dominated other countermeasures for effective $NO_x$ emission control. Large spatial differences in reduced emissions, those for Seoul being twice that of Incheon and Gyeonggi, showed greater $NO_x$ emission reduction impact in the heart of the metropolitan complex. The $NO_2$ concentration decreased by 0.60 ppb (2.0%), 0.18 ppb (1.5%), and 0.22 ppb (1.7%) in Seoul, Incheon, and Gyeonggi, respectively. Concentration decreases in spring and winter were larger, 1.5~2.0 times, than summer and fall. However, the $NO_2$ reduction impact did not correspond directly to local $NO_x$ emission controls in the city area because of the natural flow and dispersion, both urban and downwind.