• Journal of Technology Innovation
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• v.15 no.2
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• pp.123-152
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• 2007

The striking characteristic of the contemporary global security environment is that the nature of threats has become diverse and complex. For example, transnational and non-military threats including terrorism and proliferation of weapon of mass destruction has increased. In this security environment, Advanced countries funnel their investments for defense budgets into the assurance of key force capability and R&D of cutting-edge core technologies, in consideration of future battlefield environments so as to get an edge on not only defense science and technology but also intelligence capabilities. As shown by past practices of the korea's defense acquisition, the ministry of national defense has tried to enhance its force capabilities in the short-term by purchasing foreign weapon systems rather than by investing in domestic R&D. Accordingly, the technological gaps between the korea and advanced countries were widened due to both insufficient investment in development of domestic technologies and avoidance of technological transfer by advanced countries. Thus, for the effective execution of the R&D budget and the successful performance of the projects, the importance of selection, management and evaluation of the R&D projects is emphasized. So, The objective of this study is that the analysis of the proposal-selection evaluation system for the realization of the successful defense core technology R&D projects. This study focused on the improvement of the proposal-selection evaluation model which can be applicable to the national defense core R&D projects. Using the improved proposal-selection evaluation system, we propose a model to enhance the reliability of the national defense core technology R&D project evaluation system.

• Journal of Technology Innovation
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• v.22 no.1
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• pp.1-22
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• 2014

R&D investment also has a gestation period similar to other investments in economics. The gestation period originates from time lag effect of input and output. Thus it is necessary to consider time lag effects when analyzing the relationship between firms' R&D investment and R&D performance. The main objective of this research is to estimate the length of time lag effect of R&D investment. The Almon distribution lag model was applied to estimate the time lag effect. The firm level panel dataset was established from 2002 to 2009. The net value of R&D investment and the number of patent applications were used to measure R&D input and output, respectively. This method found the estimated time lag to be 1~2 years across all datasets. The same analyses were applied to chemical, metal, electronic, exact science, and machinery industries' data. And we found there were differences among sectors in regard to the time lag effect.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.31-38
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• 2008

The primary objective of this study was to evaluate the variation of the molecular size distribution by granular activated carbon (GAC) adsorption. GAC adsorption was assessed by using the rapid small-scale column test (RSSCT) and high-performance size-exclusion chromatography (HPSEC) was used to analyze the molecular size distribution (MSD) in the effluent of GAC column. RSSCT study suggested that GAC adsorption exhibited excellent interrelationship between dissolved organic carbon (DOC) breakthrough and MSD as function of bed volumes passed. After GAC treatment, the nonadsorbable fraction which was about 25percents of influent DOC corresponded to the hydrophilic (HPI) natural organic carbon (NOM) of NOM fractions and was composed entirely of <300 molecular weight (MW) in the HPSEC at the initial stage of the RSSCT operation. The dominant MW fraction in the source water was 1,000~5,000daltons. At the bed volumes 2,500, MW <500 of GAC treated water was risen rather than it of source water. After the bed volumes 7,300 of operation, the MW 1,000~3,000 fraction was closed to about 80percents of DOC found in the GAC influent. The Number-average molecular weight (Mn) value determined using HPSEC for the effluent of GAC column was gently increased as DOC breakthrough progress. The quotient p(Mw/Mn) can be used to estimate the degree of polydispersity was shown greatest value for the GAC effluent at the initial stage of the RSSCT operation.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.395-409
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• 2011

The objective of this study is to develop an accurate and robust two-dimensional finite element method for turbulence simulation in open channels. The model is based on Streamline Upwind/Petrov-Galerkin finite element method and Boussinesq's eddy viscosity theory. The method developed in the study is depth-averaged mixing length model which assumes anisotropic and local equilibrium state of turbulence. The model calibration and validation were performed by comparing with analytical solutions and observed data. Several numerical simulations were carried out, which examined the performance of the turbulence model for the purpose of sensitivity analysis. The uniform channels that appear horizontal flow and vertical flow were carried out. The model was also applied to the Han river was in for the applicability test. The results were compared with the observed data. The suggested model displayed reasonable flow distribution compare to the observed data in natural river flow. As a result of this study, the two-dimensional finite element model provides a reliable results for flow distribution based on the turbulence simulation in open channels.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3124-3124
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• 2001

The development and evolution of near infra-red spectroscopic (NIS) calibrations for high-moisture materials is an expensive proposition. Such investment is suspect unless the instrument, or instruments, on which calibrations were developed can be preserved intact or re-standardized as component replacements occurs. The objective of this paper is to detail the changes in performance of a six-year old instrument after maintenance in years five and six resulted in collection of spectral data that was increasingly removed from the calibration population. Calibrations for the analysis of mature sugarcane stalks, a high-moisture material, were developed successfully in 1995 using a broad sample population in terms of genetics, and spectral and temporal variation. The spectral library was further broadened in 1996. In 1997, 1999, 1999, and 2000, additional samples constituting 10% of the laboratories throughput were subjected to full component analyses using routine laboratory techniques. These samples were primarily random samples, but were complemented with samples that were significant for the spectral H statistic or for the component t statistic. In 1998, an additional calibration was developed for populations consisting of samples of either mature stalks (culms) or sucker culms. Substantial additional samples numbers were collected for this calibration in 1999 and 2000. Attempts to standardize the scanning spectrophotometer used for these calibrations with a second similar instrument in 1999 failed because the instruments were optically different, and standardization could not account for this. Maintenance adjustments were made to the remote reflectance probe of the original instrument in 1999, and replacement of its PbS detectors was done in 2000. Spectral data collected in 1999 and 2000 yielded spectral populations that were increasingly removed from the respective spectral populations on which the calibrations were developed. The mature stalk calibrations benefited marginally from evolutionary calib.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.139-144
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• 2010

Objective : We report our surgical experience in the treatment of 16 consecutive patients with benign craniovertebral junction (CVJ) tumor, observed from 2003 to 2008 at our department. Methods : We had treated 6 foramen magnum meningiomas, 6 cervicomedullary hemangioblastomas, 1 accessory nerve schwannoma, 1 hypoglossal nerve schwannoma, 1 C2 root schwannoma, and 1 cavernous hemangioma. Clinical results were evaluated by Karnofsky Performance Scale (KPS) and all patients underwent preoperative neuroradiological evaluation with computed tomography (CT) and magnetic resonance image (MRI). Angiography was performed in 15 patients and preoperative embolization was done in 2 patients. Results : Five far-lateral, 1 supracondylar and 10 midline suboccipital approaches were performed. Gross total removal was achieved in 15 cases (94%) and subtotal removal in 1 patient (6%). None of the patients required occipitocervical fusion. Radiological follow-up showed no recurrence in cases totally removed. Postoperative decrease of KPS scores was recorded in only 1 patient. The treatment of cervicomedullary solid hemangioblastoma presented particular issues : by preoperative embolization, we removed tumor totally without an excessive bleeding or brainstem injury. In one of foramen magnum meningioma, we carried out subtotal removal due to hard tumor consistency and encasement of neurovascular structures. Conclusion : The choice of surgical approaches and the extent of bone resection should be defined according to the location and size of individual tumors. Moreover, we emphasize that preoperative neuroradiological evaluations on presumptive tumor type could be helpful to the surgeon in tailoring the technique and providing the required exposure for different lesions, without unnecessary surgical steps.

• Journal of the Ergonomics Society of Korea
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• v.30 no.4
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• pp.551-562
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• 2011

Objective: We proposed an effective 3D menu manipulation alternative with a usability test. This was performed in a 3D environment with 3D menu and control manipulation methods. Background: As 3D stereoscopic displays became generalized, various 3D applications were being used not just movies, games, but also mobile contents and advertisements. However, when a user interface was designed in a 3D environment, it was lacked that a clear standard and result of an efficiency and usability as like a 2D environment. Method: We implemented 9 kinds of 3D menu types based on 3D menu hierarchies, menu layouts and dimensions. And we extracted 3 representative control types in a 3D environment. We performed usability evaluation with full factorial design for 27 menu alternatives with 2 types of menu manipulation tasks. In this condition, we measured the performance time, subjective discomfort and eye-fatigue. Results: A control type had the significant effect, and the effect of menu types had the different result depending on given tasks. Conclusion: This experiment showed the interaction of menu and control types depended on 3D menu manipulation tasks were significant in a 3D user interface design. Therefore, as a purpose of a 3D menu manipulation task, 3D menu types and control types were should be considered. Application: We supposed this result was should be applied in a 3D menu contents design.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.413-422
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• 2011

An improved split-beam transducer for a 50 kHz fish-sizing echo sounder was developed. The main objective of this study was to minimize the side lobe level in the beam pattern and the distance between acoustic centers for adjacent transducer quadrants in the geometrical arrangement of array elements while maintaining a given number of transducer elements and beam width. To achieve these goals, a 32-element planar array transducer ($6{\times}6$ array with one element in each corner missing) was designed using the Dolph-Chebyshev shading function to suppress side lobes in the array beam pattern and fabricated by arranging the inter-element spacing to be substantially equal to half the wavelength using the transducer element of 0.4 times the wavelength in diameter. The performance characteristics of this split-beam transducer were evaluated in the experimental water tank of $5m{\times}5m{\times}6m$ (length${\times}$height${\times}$width). In this study, the design goal of the beam width and side lobe level for transmitting a beam pattern was initially set at $21^{\circ}$ and -30 dB, respectively. However, the measured beam width at 3 dB was $21^{\circ}$ in both directions with side lobe levels of -24.7 dB in the horizontal plane and -25.6 dB in the vertical plane. The averaged beam width at -3 dB of the receiving beam patterns for four receiving quadrants was $31.4^{\circ}$. The transmitting voltage response was 161.5 dB (re $1{\mu}Pa$/V at 1 m) at 50.23 kHz with a bandwidth of 2.16 kHz, and the averaged receiving sensitivity for four receiving quadrants was -178.13 dB (re 1 V/${\mu}Pa$) at 49.8 kHz with a bandwidth of 2.64 kHz.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.79-85
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• 2011

Purpose: The aim of this study was to obtain objective and standardized information on masticatory function and patient atisfaction following second molar single implant therap. Methods: Twenty adult patient, who had restored second molar single implants more than 1 month before the study, were enrolled in this stud. All patients received a chewing test using peanuts before and after insertion of the implant prosthesi, with a questionnaire and visual analogue scale (VAS) to evaluate the effect of second molar single implant therap. Results: his study obtained standardized information on the masticatory function objectively (e.g., P, R, $X_{50}$) before (Pre-insertion) and after insertion (Post-insertion) of the implant prosthesis. Masticatory performance (P) after insertion of the implant prosthesis significantly increased from $67.8{\pm}9.9$ to $84.3{\pm}8.5$% (P<0.0001). With the implant prosthesis, the P value increased by 24%. The masticatory efficiency index (R) of Post-insertion is higher than that of Pre-insertion (P<0.0001). With the implant prosthesis, the R value increased by 29%. The median particle size ($X_{50}$) of Post-insertion is lower than that of Preinsertion (P<0.0001). More than 90% of the patients were satisfied with the second molar single implant therapy from a functional point of view. Conclusions: These findings indicate that a second molar single implant can increase masticatory function.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.513-516
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• 2003

With the size of construction projects getting larger and more complex, the amount of information is increased exponentially. Although there are a lot of construction companies that try to accumulate as-built information from construction sites. it has not been quite satisfactory. This is due to the lack of task information framework that can measure project performance and collect as-built information. Therefore the objective of the paper is to identify the information that can be derived from daily reports and to suggest a unit task information framework to accumulate as-built information.