• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.47-58
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• 2001

Of all the site logistics technologies in high-rise building construction, both vertical and horizontal move plan, are the most imperative factors. And the horizontal plan follows lift-up plan as of the vertical plan. However though it may be, temporary lifts on site are numbered by heuristic formulas. The quantity of finishing material cannot be converted into lift-up load per finishing material. The lift-up plan cannot be evaluated the feasibility for finishing material move plan by a reasonable evaluation methodology. The horizontal plan is far from the vertical one. And the information as an input data for the horizontal plan is devoid of package unit size, length, and volume per finishing material. These can hardly result in reasonable and detail decision on how much to use temporary lifts, how long to use these, and where to deposit each finishing material. Therefore, this study is to suggest a decision-making model that can integrate vertical and horizontal material move plan in high-rise building construction and make a decision the plans systematically. And the study is to explain the concept, methodology, and contents of the model applied to a virtual project, named as MT 130 (Millennium Tower 130). By the model, the planner can shift his/her thinking framework on site logistics management products-oriented Into process-oriented. He/she can manage a project by the framework as system thinking, evaluate the feasibility of a lift-up plan, and decide the horizontal plan integrated with the lift-up.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1211-1214
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• 1992

AC servo motor drives, Fara DS series, proposed in this paper can be effectively used in robots, CNC machine tools, and FA system with AC servo motors as actuators. The inverter of the AC servo drive consists of IGBT (Insulated Gate Bipolar Transistor) which have high switching frequency. Noises and vibrations generated in variable speed control of AC servo motors can be greatly reduced due to their high switching frequencies. In the developed servo drive, maximum torque is always generated in the whole speed range by compensating phase shift, which results from the nonlinearies of the AC servo motor during abrupt acceleration and deceleration. Abundant protection functions are provided to prevent abnormal state of the servo motor, and furthermore diverse user options are considered provided for the effective application. The proposed AC servo motor drive is designed to minimize velocity variation with respect to external load, supply voltage, environmental temperature, and humidity, so can be widely used in the fields of factory automation including robots and CNC msachine tools.

• Information Systems Review
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• v.10 no.2
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• pp.49-70
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• 2008

The increase in demand for e-learning has created a need to explore the implications of the emerging paradigm shift on the learning environment. To utilize information technology to improve learning processes, the pedagogical assumptions underlying the design of information technology for educational purposes must be understood. However, little theoretical development or empirical research has examined the learning effectiveness in web-based distance learning. In this regard, the primary purpose of this study is to investigate which factors of E-learning influence the effectiveness of education and expectation. Based on the prior studies of the education and business training field, research model and research hypotheses were developed. Factors studied in this paper were student characteristics, system environment and teacher characteristics. The result showed that the student characteristics has the significant effect on the effectiveness of education and expectation. However, the system characteristics and the teacher characteristics have the partial significant effects. This result is partially due to the subject characteristics of this study, because the subjects of this study are the students and they have already the experiences in IT and e-learning.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.365-370
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• 2009

For the production of diglyceride (DG) containing medium chain fatty acid, which could be utilized as a substrate to structured lipid production, monoglyceride (MG) and caprylic acid were reacted in the presence of lipase. The reaction system was well mixed homogeneously without using any organic solvent. Among the lipases investigated, Lipozyme RM IM and Novozym 435 were selected on the basis of equilibrium DG yields from the medium chain fatty acid and MG. And reaction conditions such as addition of molecular sieve, water content of immobilized lipase, reaction temperature, and mole ratio of MG/caprylic acid are optimized to increase DG production by using Lipozyme RM IM. DG content of reaction mixture showed 8% increase by adding molecular sieve to reaction mixture. Removal of water from the immobilized lipase could affect seriously equilibrium content of DG. More than 2.8%(w/w) removal of water from the support could make 44% of DG. Optimum temperature was found to $60^{\circ}C$. Temperature shift from $60^{\circ}C$ to $25^{\circ}C$ resulted in increase of free fatty acid (FFA) content. The equilibrium DG yield was not seriously affected by on MG/caprylic acid molar ratio. However, at the stoichiometric ratio of 1:1 the highest DG yield was obtained. Increasing MG/caprylic acid ratio from 0.3 to 1.8 decreased FFA content from 34% to 13%, while MG content increased from 27% to 50%.

• Journal of Biomedical Engineering Research
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• v.38 no.1
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• pp.9-15
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• 2017

Recently, flexible cages have been introduced in an attempt to absorb and reduce the abnormal load transfer along the anterior parts of the spine. They are designed to be used with the pedicle screw systems to allow some mobility at the index level while containing ROM at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the flexible cage when combined with pedicle screws with flexible rods. The post-operated models were constructed by modifying the L4-5 of a previously-validated 3-D FE model of the intact lumbar spine (L2-S1): (1) Type 1, flexible cage only; (2) Type 2, pedicle screws with flexible rods; (3) Type 3, interbody fusion cage plus pedicle screws with rigid rods; (4) Type 4, interbody fusion cage plus Type 2; (5) Type 5, Type 1 plus Type 2. Flexion/extension of 10 Nm with a compressive follower load of 400N was applied. As compared to the Type 3 (62~65%) and Type 4 (59~62%), Type 5 (53~55%) was able to limit the motion at the operated level effectively, despite moderate reduction at the adjacent level. It was also able to shift the load back to the anterior portions of the spine thus relieving excessively high posterior load transfer and to reduce stress on the endplate by absorbing the load with its flexible shape design features. The likelihood of component failure of flexble cage remained less than 30% regardless of loading conditions when combined with pedicle screws with flexible rods. Our study demonstrated that flexible cages when combined with posterior dynamic system may help reduce subsidence of cage and degeneration process at the adjacent levels while effectively providing stability at the operated level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.327-336
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• 2020

This study was undertaken to identify ways that enable a successful comeback to everyday life and improvement in the quality of life, by understanding the experiences of cancer survivors in returning to everyday life. Totally, 19 people diagnosed with complete cure after 5 years of cancer treatment, were recruited for the study. Data was collected through in-depth interviews from January 18 to February 25, 2017. One-time interviews took 90 to 120 minutes, and data analysis was achieved by applying the grounded theory. The central phenomenon of 'reality that cannot be escaped' and 'uncertain reality that cannot know tomorrow' was attributed to the causal conditions 'hard reality', 'physical exhaustion', 'psychological exhaustion' and 'economic exhaustion'. Depending on context conditions such as 'lack of family support', 'shift to a vulnerable working class', 'insufficient support system', 'hope for the societal support system', 'daunted gender', 'prejudice against cancer/cancer patients', 'information on life after rare full healing'. The strategy for a successful return was influenced by intervention conditions such as 'robust family fence' and 'effective cancer insurance', which resulted in 'building a new life' or 'enduring'. We conclude that for a successful return to daily lives, cancer survivors require comprehensive information, health and social-welfare interventions.

• Journal of Korea Technology Innovation Society
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• v.10 no.3
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• pp.383-405
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• 2007

In this paper we estimate knowledge production function for 15 South Korean industry sectors using panel data. To accommodate the influence of inter-sectoral interactions on the creation of knowledge, we estimate parameters for related knowledge production functions using the Dynamic Seemingly Unrelated Regression(DSUR) model proposed by Mark et al. (2005). We find the elasticity of knowledge production with respect to the size of research staff to be 0.25 and that with respect to the existing stock of knowledge to be 0.35. The fact that the elasticity of new knowledge creation with regard to the existing knowledge stock is below 1 in South Korea corroborates the view that the rate of long-term growth of her economy is chiefly determined by the elasticity related to production functions of goods and services and the rate of population growth, and that her government policy, to ensure a continued growth for the Korean economy, must shift the focus of R&D policies from the current direct intervention-centered model to one consisting of indirect measures, namely supporting knowledge management and diffusion and the creation of a knowledge sharing system. In terms of R&D policy implications it could be consider that the national knowledge production system should strengthen the cumulative process of knowledge accumulation and population for research and development. Our country R&D policy, also, need to adopt a global approach to increase knowledge stock at the highest levels of a country.

• Journal of Korea Technology Innovation Society
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• v.19 no.4
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• pp.768-798
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• 2016

This study started from the awareness of the issue if the citation index newly introduced to evaluate the quality of papers satisfies the proper timing matter, which is a component of performance indicators for the evaluation of government-funded R&D institutes. Accordingly, the study will propose improvement ways to shift the previous evaluation system to quality evaluation for mission-oriented R&D institutes by analysing and using the periodical characteristics such as citation half-life and immediacy index of papers. As a result, it turned out that the speed of academic change is getting faster in proportion to the dependency on the technological development but that the citation speed in the field of public technology is relatively slower and the speed of knowledge transfer in the fields related to industry is faster. In addition, the citation index among the R&D fields showed no differences, and the minimum period for citation index measurement with validity should be over 6 years. The problems of evaluation for mission-oriented R&D institutes were deducted based on the technical and statistical analysis results of the temporal characteristic of citation necessary for quality evaluation of performance among R&D fields. To solve the problems, policy alternatives for object and valid quality evaluation were proposed from the points of evaluation period and evaluation criteria.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.12
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• pp.17-26
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• 1998

Ultrasonic sensors are widely used in various applications due to advantages of low cost, simplicity in construction, mechanical robustness, and little environmental restriction in usage. But for the application of object recognition, ultrasonic sensors exhibit several shortcomings of poor directionality which results in low spatial resolution of objects, and specularity which gives frequent erroneous range readings. The time-of-flight(TOF) method generally used for distance measurement can not distinguish small object patterns of plane, corner or edge. To resolve the problem, an increased number of the sensors in the forms of a linear array or 2-dimensional array of the sensors has been used. Also better resolution has been obtained by shifting the array in several steps using mechanical actuators. Also simple patterns are classified based on analyzing signal reflections. In this paper we propose a method of a sensor array system with improved capability in pattern distinction using electronic circuits accompanying the sensor array, and intelligent algorithm based on neuro-fuzzy processing of data fusion. The circuit changes transmitter output voltages of array elements in several steps. A set of different return signals from neighborhood sensors is manipulated to provide enhanced pattern recognition in the aspects of inclination angle, size and shift as well as distance of objects. The results show improved resolution of the measurements for smaller targets.

• Atmosphere
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• v.26 no.3
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• pp.387-400
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• 2016

In this study, the atmospheric $CO_2$ concentrations estimated by CT2013B, a recent version of CarbonTracker, are compared with $CO_2$ measurements from the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project during 2010-2011. CarbonTracker is an inversion system that estimates surface $CO_2$ fluxes using atmospheric $CO_2$ concentrations. Overall, the model results represented the atmospheric $CO_2$ concentrations well with a slight overestimation compared to observations. In the case of horizontal distribution, variations in the model and observation difference were large in northern Eurasia because most of the model and data mismatch were located in the stratosphere where the model could not represent $CO_2$ variations well enough due to low model resolution at high altitude and existing phase shift from the troposphere. In addition, the model and observation difference became larger in boreal summer. Despite relatively large differences at high latitudes and in boreal summer, overall, the modeled $CO_2$ concentrations fitted well to observations. Vertical profiles of modeled and observed $CO_2$ concentrations showed that the model overestimates the observations at all altitudes, showing nearly constant differences, which implies that the surface $CO_2$ concentration is transported well vertically in the transport model. At Narita, overall differences were small, although the correlation between modeled and observed $CO_2$ concentrations decreased at higher altitude, showing relatively large differences above 225 hPa. The vertical profiles at Moscow and Delhi located on land and at Hawaii on the ocean showed that the model is less accurate on land than on the ocean due to various effects (e.g., biospheric effect) on land compared to the homogeneous ocean surface.