• Korea and Global Affairs
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• v.1 no.1
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• pp.97-114
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• 2017

This article aims for searching the clue of North Korea nuke-problem by understanding it contextually. We must see this from the beginning as many trials in settling the problem have failed. North Korea nuke-problem is related to the change of international implication as well as the domestic process of its development. At first, it started from the regime survival, which evolved with the effect of learning. During the Cold War, its development had combined the principle of 'self-defense' because of Sino-Russia conflict. Particularly, its meaning varied dramatically due to the collapse of Cold War system plus the advent of post-Cold War system. North Korea nuclear program has became a global problem based on the deterioration of North Korea's security milieu and Bush administration's policy. Therefore, the area of common solution for NK nuke-problem must be found in the context of regime survival and the change of its meaning by continual convergence effort.

• Progress in Superconductivity
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• v.9 no.1
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• pp.50-55
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• 2007

We have installed a 61-channel magnetocardiography (MCG) system inside a magnetically shielded room (MSR) with a size of $2.4\;m\;{\times}2.4\;m\;{\times}2.4\;m$. The MCG system consists of 1st-order axial gradiometers containing double relaxation oscillation SQUIDs (DROSs) with pick-up coils of a base line of 70 mm. The MSR holds a shielding factor of 50 at 0.1 Hz and 10000 at 100 Hz, when its door in the middle on a front wall is closed. On opening the MSR door, we have obtained the characteristics of the MCG system with a 2.9 Hz noise generated from an air conditioning unit at 13 m distance off the MSR. In an open-door MSR ($140^{\circ}$ opening), a noise at the center channel increases up to $700\;fT/Hz^{l/2}$ at 2.9 Hz and $1.7\;pT/Hz^{1/2}$ at 60 Hz. MCG signals for a healthy human do not show distortion until the door opens to $45^{\circ}$, but show the effect of noise when the door opens further at $90^{\circ}$ and $140^{\circ}$. With the door opens to $45^{\circ}$, MCG measurement can be performed with ease of door operation and without creating claustrophobia for the patient.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.955-959
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• 2003

Rhizobium tropici CIAT 899 is capable of synthesizing inactive apo-glucose dehydrogenase (GDH). To become an active holo enzyme, the GDH requires a cofactor, PQQ. When R. tropici CIAT 899 was grown in a broth culture medium containing hydroxyapatite and pyrrolo quinoline quinone (PQQ), pH decreased while the concentration of soluble P increased. The solubilization of hydroxyapatite was associated with the production of gluconic acid and 2-ketogluconic acids. The organic acid production and P solubilization were greatly enhanced when the bacterium was grown with air supply. Effect of R. tropici CIAT 899 with (CI＋PQQ) and without PQQ (CI) on the common bean growth was examined. Shoot and root weight, and N and P contents in CI＋PQQ treatment, were significantly higher than those in control and CI treatment. Nodule weight and acetylene reducing activities were also significantly higher in CI＋PQQ treatment than in other treatments.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.6-10
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• 1999

The field size can be beam output, therefore MonitorUnit can be varied due to field size dependence The purpose of this study is to evaluate and compare the dose variation according to exchange of collimator The measurements were perfomed with Wellhofer dosimetry system(water phantom. ion chamber. electrometer. system controller. build up cap. etc)and two types of linear accerlerator (Mevatron KD, MevatronMX) Scatter can be affected to field size dependence and scatter correction is separated into collimator and phantom components, scatter components can affect by exchanging of collimator Measurements of collimator scatter factor(Sc) was done in air with build up cap. 1)Square field (5cm2 to 40cm2) was measured 2)and then keeping the upper jaw constant at loom and varing lower jaw from 5cm to 40cm, 3)keeping the lower jaw constant at 10cm and varing upper jaw from 5cm to 40cm Measurements of total scatter factor(Scp) was done in water at Dmax as the procedure of collimator scatter factor measurements in water Dmax The total scatter factors were obtained to the following equation(Sp=Scp/Sc) The measured data is normalized to the data of reference field size($10{\times}10$), rectangular field is inverted to equivalent field to compare three field size data As the collimator setting is varied, the output was changed In conclusion, the error was obtained small but it must be eliminated if we intend to reach the common stated goal of $5\%$ overall uncertainty in dose determination

• Journal of Advanced Navigation Technology
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• v.8 no.1
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• pp.19-26
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• 2004

This paper deals with the automatic flight control system for an unmanned target drone which is operated by an army as an anti-air gun shooting training. By automation of unmanned target drone that is manually operated by external pilot, pilot can reduce workload and an army can reduce the budget. Most UAVs which are developed until today use high-cost sensors as AHRS and IMU to measure the attitude, but those are contradictory for the reduction of budget. This paper says the development of low-cost automatic flight control system which makes possible of automatic flight with low-cost sensors. We have developed the integrated automatic flight control system by integrating electricity module, switching module, monitoring module and RC receiver as an one module. We also prove the performance of automatic flight control system by flight test.

• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.640-648
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• 2020

Objective : This study aimed to assess the relationship between increased intracranial pressure (ICP) and mastoid effusions (ME). Methods : Between January 2015 and October 2018, patients who underwent intracranial surgery and had ICP monitoring catheters placed were enrolled. ICP was recorded hourly for at least 3 days. ME was determined by the emergence of opacification in mastoid air cells on follow-up brain imaging. C-reactive protein (CRP) levels, presence of endotracheal tube (ETT) and nasogastric tube (NGT), duration of intensive care unit (ICU) stay, duration of mechanical ventilator application, diagnosis, surgical modalities, and presence of sinusitis were recorded. Each factor's effect on the occurrence of ME was analyzed by binary logistic regression analyses. To analyze the independent effects of ICP as a predictor of ME a multivariable logistic regression analysis was performed. Results : Total of 61 (53%) out of 115 patients had ME. Among the patients who had unilateral brain lesions, 94% of subject (43/50) revealed the ipsilateral development of ME. ME developed at a mean of 11.1±6.2 days. The variables including mean ICP, peak ICP, age, trauma, CRP, ICU stays, application of mechanical ventilators and presence of ETT and NGT showed statistically significant difference between ME groups and non-ME groups in univariate analysis. Sex and the occurrence of sinusitis did not differ between two groups. Adding the ICP variables significantly improved the prediction of ME in multivariable logistic regression analysis. Conclusion : While multiple factors affect ME, this study demonstrates that ICP and ME are probably related. Further studies are needed to determine the mechanistic relationship between ICP and middle ear pressure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1658-1663
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• 2015

To control the indoor humidity, humidifier is installed in an air handling unit. Up to now, foreign product made of glasswool has been widely used as a humidifying element. In this study, a new humidifying element made of cellulose and PET was tested, and the performance was compared with Glasdek element, which is made of glasswool. Mass transfer rates and pressure drops were measured from the element which was installed at the entrance of the suction-type wind tunnel. Results show that, $j_m$ and f factors of the new element are 33%~39% larger and 0%~51% smaller than those of Glasdek. Large water absorption capacity and the smoothness of the new element appear to be responsible for the large $j_m$ and small f factor. The mass transfer effectivenesses ($j_m/f^{1/3}$) of the new element are 36%~63% larger than those of Glasdek.

• Journal of the Korean Society of Safety
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• v.31 no.4
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• pp.55-63
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• 2016

A dust explosion is a phenomenon of strong blast wave propagation involving destruction which results from dust pyrolysis and rapid oxidation in a confined space. There has been some research done to find individual explosion characteristics and common physical laws for various dust types. However, there has been insufficient number of studies related to the heat of combustion of materials and the oxygen consumption energy about materials in respect of dust explosion characteristics. The present study focuses on the relationship between dust explosion characteristics of wood dust samples and oxygen consumption energy. Since it is difficult to estimate the weight of suspended dust participating in explosions in dust explosion and mixtures are in fuel-rich conditions concentrations with equivalent ratios exceeding 1, methods for estimating explosion overpressure by applying oxygen consumption energy based on unit volume air at standard atmospheric pressure and temperature are proposed. In this study an oxygen consumption energy model for dust explosion is developed, and by applying this model to TNT equivalent model, initial explosion efficiency was calculated by comparing the results of standardized dust explosion experiments.

• Environmental Analysis Health and Toxicology
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• v.24 no.2
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• pp.149-157
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• 2009

In this study, recognized building-related health symptoms of various workers in dental college hospitals are surveyed and analyzed in order to improve indoor environment at dental college hospitals. We conducted a questionnaire survey for 682 workers in three dental college hospitals located in Seoul from Sep. 20 to Oct. 8, 2004. Most workers at dental hospitals complained about noise, poor ventilation, dusty environment, and air dryness. SBS symptoms score for subjects was 1.43${\pm}$0.74 (often feel) and major symptoms was throat, CNS, eye, and nose symptoms. Recognized Building-related health symptoms are significantly related to tasks, working experience, job-satisfaction, indoor environment recognition index, medical history, used to special material, and number of dental unit chair. Also working places and ventilation are significantly related to the symptom. Based on the results, it can be said that special dental treatment causes undesirable environment such as noise, dust, and bad odor. It is also related to recognized building related health symptoms reported by workers at dental hospitals. So managemental efforts are needed to improve indoor environment which is related by dental treatment.

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.240-246
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• 2013

Airtouch technology to integrate the system in the way of information delivery devices, touch screen DID this study is to develop new ways of information delivery systems. Airtouch technology to design and implement a system that can be utilized to view the college campus announcements, education, information, and employment information, and store the remote operation and sharing content, the development of cloud services to sync content via smart technology implementation fusion DID systemto develop. Packs USB interface kinek because you may be used in connection with the information appliances, and low-cost product by leveraging the Kinect sensor, Airtouch technology implementation. Types of input devices paper Airtouch technology systems, the user's hand gestures alone can interact with information appliances, smart fusion system developed by DID by tracking the user's hand movements to manipulate the mouse pointer, and information through the user's hand gestures to command the unit so that you can make. Airtouch technology smart fusion DID system technology utilizing a ripple effect on other industries, such as the online education industry, advertising, information industry increases. Also, replace the existing interface device with the versatility of a wide range of technologies, usability is an infinite expansion.