• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.89-93
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• 2017

Infratentorial cerebral hemorrhage due to a direct carotid-cavernous fistula (CCF) is very rare. To our knowledge, only four such cases have been reported. Cerebellar hemorrhage due to a direct CCF has not been reported. We describe a 63-year-old female who presented with reduced consciousness 3 days after undergoing a maxillectomy for maxillary cancer. Computed tomography showed a cerebellar hemorrhage. Magnetic resonance angiography showed a left-sided direct CCF draining into the left petrosal and cerebellar veins through the left superior petrosal sinus (SPS). Her previous surgery had sacrificed the pterygoid plexus and facial vein. Increased blood flow and reduced drainage could have led to increased venous pressure in infratentorial veins, including the petrosal and cerebellar veins. The cavernous sinus has several drainage routes, but the SPS is one of the most important routes for infratentorial venous drainage. Stenosis or absence of the posterior segment of the SPS can also result in increased pressure in the cerebellar and pontine veins. We emphasize that a direct CCF with cortical venous reflux should be precisely evaluated to determine the hemodynamic status and venous drainage from the cavernous sinus.

• Journal of Korean Neurosurgical Society
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• v.41 no.5
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• pp.323-326
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• 2007

Direct carotid-cavernous fistula [CCF] is a common post-traumatic disease. However, pseudoaneurysm formation after balloon occlusion is a rare complication. The author present such a case with review of the literature. A 26-year-old man involved in a motor vehicle accident as a driver. Only mild conjunctival injection and minimal exophthalmos on the right eye were noted after trauma. However, angiography revealed a direct CCF and dissection of the proximal intracranial internal carotid artery [ICA]. After first balloon occlusion of the CCF, the patient redeveloped fistula due to early deflation of the balloon. After the second balloon occlusion, pseudoaneurysm and diplopia were developed with the change of balloon position and shape. However, visual symptom spontaneously resolved and pseudoaneurysm was also decreased within 6 months after balloon occlusion.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.226-228
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• 2011

We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.5
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• pp.445-457
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• 2017

In this study, we developed an approach to better account for uncertainties in estimated contributions from fine particulate matter ($PM_{2.5}$) modeling. Our approach computes a Concentration Correction Factor (CCF) which is a ratio of observed concentrations to baseline model concentrations. We multiply modeled direct contribution estimates with CCF to obtain revised contributions. Overall, the modeling system showed reasonably good performance, correlation coefficient R of 0.82 and normalized mean bias of 2%, although the model underestimated some PM species concentrations. We also noticed that model biases vary seasonally. We compared contribution estimates of major source sectors before and after applying CCFs. We observed that different source sectors showed variable magnitudes of sensitivities to the CCF application. For example, the total primary $PM_{2.5}$ contribution was increased $2.4{\mu}g/m^3$ or 63% after the CCF application. Out of a $2.4{\mu}g/m^3$ increment, line sources and area source made up $1.3{\mu}g/m^3$ and $0.9{\mu}g/m^3$ which is 92% of the total contribution changes. We postulated two major reasons for variations in estimated contributions after the CCF application: (1) monthly variability of unadjusted contributions due to emission source characteristics and (2) physico-chemical differences in environmental conditions that emitted precursors undergo. Since emissions-to-$PM_{2.5}$ concentration conversion rate is an important piece of information to prioritize control strategy, we examined the effects of CCF application on the estimated conversion rates. We found that the application of CCFs can alter the rank of conversion efficiencies of source sectors. Finally, we discussed caveats of our current approach such as no consideration of ion neutralization which warrants further studies.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.113-114
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• 2004

In order to classify the groundwater recharge characteristics in an urban area, a time series analysis of groundwater level data was performed. For this study, the daily groundwater level data from 35 monitoring wells were collected for 3 years (Fig. 1). The use of the cross-correlation function (CCF), one of the time series analysis, showed both the close relationship between rainfall and groundwater level change and the lag time (delay time) of groundwater level fluctuation after a rainfall event. Based on the result of CCF, monitored wells were classified into two major groups. Group I wells (n=10) showed a fast response of groundwater level change to rainfall event, with a delay time of maximum correlation between rainfall and groundwater level near 1 to 7 days. On the other hand, the delay time of 17-68 days was observed from Group II wells (n=25) (Fig. 1). The fast response in Group I wells is possibly caused by the change of hydraulic pressure of bedrock aquifer due to the rainfall recharge, rather than the direct response to rainfall recharge.

• Journal of National Security and Military Science
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• s.8
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• pp.1-48
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• 2010

The purpose of this study is to examine and analyze the Untied Nations' efforts for peace on Korean peninsular after CCF's participation in Korean War. The Untied Nation tried to negotiate th peace plan between two sides from the end of 1950. Once the CCF's entry into the war had been confirmed, the war situation moved to a new phase, and the UN forces, which had guided the war in an effort to destroy the NKP A forces, and to punish North Korea, had to set up new guidelines to cope with the new situation. Accordingly, in late November, 1950, the UN forces camp, mainly the US Joint Chiefs of Staff and the United Nations Command, discussed various options, such as an expansion of the war up to the Chinese territory, a cease fire along the 38th Parallel, or a forced and inevitable evacuation. The Korean delegation to the UN insisted that "the unification of Korea should be achieved only by victory in the war. The Chinese intervention in the war is a Challenge to the UN in the same way as the North Korean invasion. The UN participation in the war was to repulse the invasion. With the same spirit we should drive back the Chinese Communists." The Korean delegation also emphasized to the friendly nations the political objective and will of unification, and that a cease fire at a threshold of unification might return us to the status quo ante bellum, and would be contrary to the Korean nation's desire. At that time, particularly, the US strongly considered the employment of nuclear weapons as one of the new strategies to cope with the Chinese invasion. The international effects of these casual remarks were realized almost at once. The British Prime Minister who had not wanted the expansion of war in the Far East, especially from the view point of the interest of NATO's security, visited Washington. so the conference had a very important meaning for the UN forces' new strategy. On the other hand, at the UN, on the 5th of December, the very day Truman and Attlee agreed to seek a cease-fire under UN auspices, a group of thirteen Asian and Arab states proposed to ask China and North Korea not to cross the 38th Parallel, and sounded out both sides about a cease fire along the 38th Parallel. The United States and the United Kingdom gave their assent, but China and North Korea gave no direct response. The CCF, who were securing the initiative of operation, were not agreeable with the proposal of the UN forces. The Untied Nation has tried to negotiate th peace plan between two sides from the December of 1950 and January of 1951. The Untied Nations' has achieved great results to negotiate for the peace plan on Korean peninsular after CCF's participation in Korean War. It's the results considering both the operation situation and political opinions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.264-272
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• 2012

TRL has a direct impact on development schedule and cost in the system or technology development projects. If TRL capability of development organization for specified CTEs can be accurately assessed and the impact of TRL on development schedule and cost are analyzed as detailed as possible, the risk of development schedule delay and cost increase can be minimized during the development process. This paper describes analysis results of TRL impact on development schedule and cost in the aerospace project. The development schedule and cost change are quantitatively estimated for the TRL improvement in the Unmanned Aerial Vehicle(UAV) system development program.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.3
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• pp.35-40
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• 2010

In this paper, we propose a hardware resource sharable camera control processor (CCP) for low-cost and low-power camera cell phones. The main idea behind the proposed architecture is that adds direct access paths in the CCP to share its hardware resources so that the baseband processor expands its capabilities and boosts its performance by utilizing CCF's hardware resources. In addition, we applied a module grain dock-gating method to reduce power dissipation. Hence, the CCP can realize low-power and low-cost camera cell phones with greater hardware efficiency. This chip was fabricated in a 0.18um CMOS process with an active area of $3.8mm\;{\times}\;3.8mm$.