• Nuclear Medicine and Molecular Imaging
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• 제40권4호
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• pp.233-236
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• 2006

A 67-year-old man with a history of chronic obstructive pulmonary disease (COPD) underwent F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging of gastric cancer. The projection images of F-18 FDG PET/CT showed intensely increased F-18 FDG uptake in the anterior neck, chest wall, and upper abdomen. We suspected distant metastases of cervical lymph nodes, ribs, and peritoneum in gastric canter. However, the transaxial images of F-18 FDG PET/CT showed abnormal F-18 FDG uptake in scalene muscles of anterior neck, intercostal muscles of chest wall, and diaphragm of upper abdomen. Patients with COPD use respiratory muscles extensively on the resting condition. These excessive physiologic use of respiratory muscles causes increased F-18 FDG uptake as a result of increased glucose metabolism. The F-18 FDG uptake in respiratory muscles of gastric cancer patient with COPD mimicked distant metastases in cervical lymph nodes, ribs, and peritoneum.

• 대한위생학회:학술대회논문집
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• 대한위생학회 2004년도 심포지움
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• pp.54-65
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• 2004

Use of aluminum salts as coagulants In water treatment may lead to increased concentrations of aluminum in finished water. Aluminum is a suspected causative agent of neurological disorders such as Alzheimer's disease. The objective of this study was to examine variation and minimizing in residual aluminum concentration during water treatment process. The aluminum sources at Bokjeong Water Plant were present naturally aluminum in the raw water and derived due to use of PACS as a coagulant. Much of the raw water total aluminum were in particulate and suspended aluminum. In this study was compared the optimize condition to minimize the concentration of residual aluminum using Jar-test with the various coagulants such as alum, PAC, PACS. The results indicated that PACS was more effective than alum, PAC and insufficient or excessive alum, PAC, PACS addition led to increase residual aluminum. Adjustment raw water pH $6.5\~7.0$ before coagulation using PACS was capable of minimizing total and dissolved aluminum. Thus it is important that the optimal dosage of coagulant and the optimal pH adjustment before coagulation can decided to minimize the concentration of residual aluminum in treated water.

• 한국구조물진단유지관리공학회 논문집
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• 제7권1호
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• pp.239-249
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• 2003

20, 30 년 전 시골지역에 건설된 교량들은 과도한 교통량의 증가에 따른 초과하중을 지탱해야한다. 이러한 교량들에 대해서 보수 보강이나, 교량의 교체가 필요하다. 고가의 보수 보강을 피하기 위해는, 현재 교량의 내하력을 정확히 알아야한다. 내하력 평가자들은 교량의 내하력을 평가하기 위해 허용응력법, 강도설계법, 그리고 하중저항계수법등을 사용한다. 본 연구에서는, 내하력 평가방법을 설명하고, 문헌조사를 통해 교량의 하중실험 자료의 이용에 대하여 설명한다. 그리고, 30년전에 시골지역에 건설된 교량에 대해 하중실험을 하였다. 시험자료로 부터, 교량의 교체를 대신한 새로운 보수보강 방법이 제시되었다.

• 한국주거학회논문집
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• 제27권4호
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• pp.77-88
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• 2016

Low-rise Residential neighborhoods of Hongdae area, Garosu-gil, Samchung-dong, Itawon etc. are currently emerging new spaces for cultural consumption in the city. Nonetheless undiscerning excessive commercialization often results in monotonous urban space and deportation of residents and leaders of change; Due to commercialization and popularization recently this phenomenon is influencing surrounding low-rise residential neighborhoods. The main objective of this study is to examine how surrounding low-rise residential neighborhood transforms according to the expansion of culture-commerce spaces. Hongdae area's culture-commerce spaces and its expansion into Yeonnam-dong is investigated in specific. Especially attributes and main causes of transformation in physical and experiential space of neighborhood living facilities and residential buildings, when changed into culture-commerce related use is examined in detail. The expansion of culture-commerce space of Hongdae to Yeonnam-dong area has positive meaning in aspects of everyday experience. First, physical alteration of street-building relation increases direct and indirect contact of people. Contact opportunity carries important meaning in sense that it is prerequisite for next stage contact of network and exchange. Second, culture-commerce related programs provide the third place, where various leisure activities can take place. Attributes of transformation and positive meaning of culture-commerce spaces expanding its territory presents the need of management.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1756-1767
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• 2008

Recently, a global trend has been established to facilitate the use of waste materials in geotechnical engineering applications. In Korea, where there is the need to save natural resources as these may become scare in the near future and to prevent excessive ground excavation for natural aggregates. The annual production of scrap tire and bottom ash has sharply increased in recent years. Therefore, it will be good waste resource recycling, if we can utilize the above wastes as fill materials in soft ground. In this study, based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material(soil) with bottom ash. Therefore, the main objective of this research is to investigate the feasibility of tire shred-bottom ash mixtures in order to estimate their suitability for the use of lightweight fill materials. So we carried out the performance tests of 2 large scale embankment which were made with tire shred-bottom ash mixture and the conventional fill material(weathered soil) respectively.

• 대한조선학회논문집
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• 제41권4호
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• pp.77-84
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• 2004

Active control is regarded as one of the most efficient and economic countermeasures to reduce excessive vibration of ship superstructure. However, it is difficult to find its practical application in real ships in spite that many studies on such systems have been done. In this study, for the practical use of an active control system to reduce ship superstructure vibration, we have developed an active vibration compensator consisting of a mechanical actuator having compact size and expected lifetime over 20 years, its control panel including exclusive signal processing and computing board, sensors to detect phase and vibration, and its operation software providing various user-interface functions. From the performance verification test of the system at a 5,500 TEU container carrier, we have confirmed the system could reduce ship superstructure vibration of a harmonic component of main engine rotating frequency up to 0.1 mm/s.

• 설비공학논문집
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• 제22권2호
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• pp.78-85
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• 2010

A dynamic model has been developed to investigate the operability of a single and double-effect solar energy assisted parallel type absorption chiller. In the study, main components and fluid transport mechanism were modeled. And solar radiation and the solar collector were also modeled along with its control design. The model was run for the single mode with solar energy supply only and the solar/gas driving double effect mode. From the simulation results, it was found that the present configuration of the chiller is not capable of regulating solution flow rates according to variable solar energy input. And the issues of the excessive circulation flow rate and the mismatch between available solar power and cooling load discourages the use of the single mode, but the dual use of gas and solar power is recommendable in view of controllability and enhanced COP.

• 한국인터넷방송통신학회논문지
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• 제9권4호
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• pp.123-127
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• 2009

Cognitive Radio 환경에서 서비스영역 밖에 있는 사용자는 통신을 하지 못하도록 규정을 하고 있다. 그 이유는 주사용자가 서비스를 제공받는데 피해나 간섭의 영향을 대비하기 위해서이다. 이와 같은 규정이 보장된다면, CR 사용자는 서비스 영역 밖에서도 충분히 서비스를 제공받을 수 있게 된다. 본 논문에서는 주 사용자에게 과도한 간섭을 발생시키지 않는 실용적 시스템에 대한 논의, 즉, 제안된 기법을 통해 부사용자를 위한 가능한 이득이 주사용자에게 비간섭이 되는 사항에 중점을 둔다. 본 논문에서는 그 방법을 BBA(Bi-directional Beamforming Antenna), 즉 지향성 양방향 안테나를 이용하여 제시한다.

• 한국군사과학기술학회지
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• 제23권4호
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• pp.389-398
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• 2020

Test cases in the existing weapon system software were created manually by the tester analyzing the test items defined in the software integration test procedure. However, existing test case generation method has two limitations. First, the quality of test cases can vary depending on the tester's ability to analyze the test items. Second, excessive time and cost may be incurred in writing test cases. This paper proposes a method to automatically generate test cases based on the requirements model and specifications to overcome the limitations of the existing weapon system software test case generation. Generate test sequences and test data based on the use case event model, a model representing the requirements of the weapon system software, and the use case specification specifying the requirements. The proposed method was applied to 8 target models constituting the avionics control system, producing 30 test sequences and 8 test data.

• 한국군사과학기술학회지
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• 제5권1호
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• pp.24-36
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• 2002

직접확산 통신시스템의 성능을 최대한 활용하기 위해서는 통신 대역을 적절히 활용하여 사용자의 수를 많게 하여 주파수 자원을 효율적으로 사용하는 것이 중요하다. 본 논문에서는 DS-CDMA시스템의 기저대역 변조방식을 MPSK, QAM, MFSK, 및 PR부호기로 사용할 때, 각각의 변조방식별로 사용자수를 증가시키면서 비트오율을 예측하여 시스템의 성능을 상호 비교하였다. BPSK방식은 전반적으로 우수한 성능을 가지며, FSK 방식은 단말이 저전력으로 운용될 경우 상대적으로 우수한 성능을 갖는다. PR 방식은 단말이 고전력으로 운용될 경우 상대적으로 우수하며, 사용자 수가 폭주할 경우에 우수한 성능을 갖는다. QAM방식은 성능이 나빠 대역확산 통신시스템에 적합하지 않은 것으로 나타났다.