• Advances in pediatric surgery
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• 제5권2호
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• pp.141-145
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• 1999

Idiopathic small bowel ulceration distal to the duodenum is rare. Less than 5 % of the reported cases were in children. In the majority of the patients, a single ulcer of unknown cause is found in the jejunum or ileum. The diagnosis is difficult and usually made at the time of surgical exploration for complications, such as perforation, hemorrhage or obstruction. We treated a pediatric patient with perforation of an idiopathic ileal ulceration. The child was an 11-year-old boy who sustained blunt abdominal trauma. The involved ileal segment was resected. Pathologic findings were compatible with idiopathic small bowel ulceration. The clinical and pathological aspects of idiopathic ulcerations are discussed, and the literature reviewed.

• 대한핵의학회지
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• 제38권2호
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• pp.131-139
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• 2004

Small animal models are extensively utilized in the study of biomedical sciences. Current animal experiments and analysis are largely restricted to in vitro measurements and need to sacrifice animals to perform tissue or molecular analysis. This prevents researchers from observing in vivo the natural evolution of the process under study. Imaging techniques can provide repeatedly in vivo anatomic and molecular information noninvasively. Small animal imaging systems have been developed to assess biological process in experimental animals and increasingly employed in the field of molecular imaging studies. This review outlines the current developments in nuclear medicine imaging instrumentations including fused multi-modality imaging systems for small animal imaging.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.109-111
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• 2001

Modern power grids are becoming more and more stressed with the load demands increasing continually. Therefore large stressed power systems exhibit complicated dynamic behavior when subjected to small disturbance. Especially, it is needed to analyze special conditions which make small signal stability structure varied according to operating conditions. This paper shows that the relation between small signal stability and operating conditions can be predicted well using node-focus point and 1:1 resonance point. Also, the weak point which limits operating range can be identified by the analysis of resonance condition. The proposed method is applied to test systems, and the results illustrate its capabilities.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권3호
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• pp.204-209
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• 2005

A small size broadband microstrip patch antenna with small ground plane has been fabricated using MEMS. Multiple layer substrates are used to realize small size and broadband characteristics. The microstrip patch is divided into 3 pieces and each patch is connected to each other using a metal microstrip line. The fabrication process is simple and only one mask is needed. Two types of microtrip antennas are fabricated. Type A is the micros trip antenna with metal lines and type B is the microstrip antenna without metal lines. The size of proposed microstip antenna is $8^{*}12^{*}2mm^{3}$ and the experimental results show that the antenna type A and type B have the bandwidth of 420 MHz at 5.3 GHz and 480 MHz at 5.66 GHz, respectively.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.603-604
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• 2006

A small size broadband microstrip patch antenna with small ground plane has been fabricated using MEMS. Multiple layer of high and low dielectric substrates are used to realize small size and broadband characteristics. The microstrip patch is divided into 4 pieces and each patch is connected to each other using a metal microstrip line. The fabrication process is very simple and only one mask is needed. Two types of microtrip antennas are fabricated. Type A is the microstrip antenna with metal lines and type B is the microstrip antenna without metal lines. The size of proposed microstip antenna is $8*12*2mm^3$ and the experimental results show that the antenna type A and type B have the bandwidth of 420MHz at 5.3 GHz and 480MHz at 5.66 GHz, respectively.

• Smart Structures and Systems
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• 제21권3호
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• pp.335-347
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• 2018

The fast-growing number of mobile and wearable applications has driven several innovations in small-scale electret-based energy harvesting due to the compatibility with standard microfabrication processes and the ability to generate electrical energy from ambient vibrations. However, the current modeling methods used to design these small scale transducers or microgenerators are applicable only for constant-speed rotations and small sinusoidal translations, while in practice, large amplitude sinusoidal vibrations can happen. Therefore, in this paper, we formulate an analytical model for electret-based microgenerators under general sinusoidal excitations. The proposed model is validated using finite element modeling combined with numerical simulation approaches presented in the literature. The new model demonstrates a good agreement in estimating both the output voltage and power of the microgenerator. This new model provides useful insights into the microgenerator operating mechanism and design trade-offs, and therefore, can be utilized in the design and performance optimization of these small structures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2319-2337
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• 2019

In this paper, we study the distributed cooperative caching for Internet content providers in a small cell of heterogeneous network (HetNet). A general framework based on bankruptcy game model is put forth for finding the optimal caching policy. In this framework, the small cell and different content providers are modeled as bankrupt company and players, respectively. By introducing strategic decisions into the bankruptcy game, we propose a caching value assessment algorithm based on analytic hierarchy process in the framework of bankruptcy game theory to optimize the caching strategy and increase cache hit ratio. Our analysis shows that resource utilization can be improved through cooperative sharing while considering content providers' satisfaction. When the cache value is measured by multiple factors, not just popularity, the cache hit rate for user access is also increased. Simulation results show that our approach can improve the cache hit rate while ensuring the fairness of the distribution.

• 유통과학연구
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• 제22권6호
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• pp.69-81
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• 2024

Purpose: Small airports are social and economic enablers and facilitate businesses and individuals. They contribute significantly to the distribution and logistics of the local produce - be it goods or services, thereby impacting the economy but have limited access to funds and poor management restricts their development. Despite the importance, small airports in small cities struggle financially as they are unable to earn profits and have higher operating costs. In other words, this is a paradoxical situation for small airports wherein, despite losses, the regional or national public authorities still finance such airports under socio-economic obligations. Therefore, this study aims to identify the critical success factors for improving small airports' performance and propose a business model. Research design, data and methodology: Using the qualitative research, interviews with 16 stakeholders from Guwahati, Tirupati, Bhubaneswar and Dehradun airports in india were examined. Results: The analysis reveals strategic planning and low cost, non-passenger services, and development of airport economic region as the main factors contributing towards small airports' success. Additionally, providing logistics to the local businesses and creating niche markets are suggested. Conclusions: Small airports, based on their services and the means of targeting customers, could select the relevant approach to improve their overall performance and improve profitability.

• 한국환경과학회지
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• 제17권9호
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• pp.981-992
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• 2008

This study examined how to produce new methods of copper (II) sulfate crystallization by using a small-scale chemistry tool such as small-scale reaction surface and petri dish. The making of copper(II) sulfate is included in the 5th grade elementary science textbooks. Various copper(II) compounds were reacted with a 2 M sulfuric acid solution. The result of this study is as follows: Seven small amounts of copper(II) compounds were reacted with a few drops of 2 M sulfuric acid solution at room temperature to make a copper(II) sulfate crystal of triclinic shape. Using the petri dish method, a copper(II) sulfate crystal could be identified within one hour of reacting copper(II) hydroxide, copper(II) carbonate, copper(II) nitrate, copper(II) perchlorate, cupric(II) formate from a few drops of 2 M sulfuric acid solution at room temperature. When using the lap top method for copper(II) perchlorate, cupric formate, a proper crystal could be identified within one hour as well. SSC methods were used for the first time to make a copper sulfate crystal via chemical reaction. We can make a copper(II) sulfate crystal using a simple method which is easier, safer and saves time in class. And since a small quantity of chemicals are being used in SSC chemical methods, waste is greatly reduced. This lessens the amount of environmental problems caused by the experiment. This can be helpful in preserving nature. In addition the cost of chemical and laboratory equipment is greatly reduced because it uses material that we find in our daily lives. There will be continued study of small-scale methods such as improvement of new programs, study and training of teachers, and securing SSC tools. I would like to suggest such as SSC methods are applicable in elementary School Science. I would like it to become a wide spread program.

• Tuberculosis and Respiratory Diseases
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• 제65권3호
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• pp.230-234
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• 2008

본 증례에서 환자는 폐렴 치료 중 갑자기 발생한 복통을 주소로 급성 충수염을 진단받고 수술을 시행 받았다. 그 후 조직 검사 결과 소세포암으로 진단되었고 폐병변에 대해 추가적인 검사 결과 소세포폐암이 진단된 경우이다. 저자들은 소세포폐암의 충수 전이를 국내에서 처음으로 경험하여 문헌고찰과 함께 보고하는 바이다.