• 대한공간정보학회지
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• 제20권2호
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• pp.81-91
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• 2012

최근 유비쿼터스 컴퓨팅 환경이 발전함에 따라 u-GIS는 유비쿼터스 컴퓨팅 환경의 핵심 요소 기술로 대두되고 있고 이에 따른 시공간 데이터의 효율적인 관리에 대한 연구가 활발히 이루어지고 있다. 이러한 u-GIS 환경에서 모바일 장치는 나날이 증가하고 있는 대용량 시공간 데이터를 효율적으로 관리하기에는 어려움을 가지고 있다. 따라서 본 논문은 모바일 장치용 시공간 질의 처리 시스템을 개발하였다. 모바일 장치용 시공간 질의 처리 시스템은 시공간 데이터에 대한 삽입/삭제/갱신/검색을 위한 다양한 시공간 연산자를 제공한다. 그리고 플래시 메모리에 최적화된 시공간 인덱스와 질의 수행 속도를 보장하기 위해 시공간 히스토그램을 이용한 질의 최적화 기능을 제공한다. 마지막으로, 모바일 장치용 시공간 질의 처리 시스템을 가상 시나리오에 적용함으로써 본 시스템이 모바일 환경에서 다양한 u-GIS 응용 분야에 유용하게 활용될 수 있다는 것을 검증하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권4호
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• pp.291-302
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• 2013

NAND flash memory (NFM) based storage devices, e.g. Solid State Drive (SSD), are rapidly replacing conventional storage devices, e.g. Hard Disk Drive (HDD). As NAND flash memory technology advances, its specification has evolved to support denser cells and larger pages and blocks. However, efforts to fully understand their impacts on design objectives such as performance, power, and cost for various applications are often neglected. Our research shows this recent trend can adversely affect the design objectives depending on the characteristics of applications. Past works mostly focused on improving the specific design objectives of NFM based systems via various architectural solutions when the specification of NFM is given. Several other works attempted to model and characterize NFM but did not access the system-level impacts of individual parameters. To the best of our knowledge, this paper is the first work that considers the specification of NFM as the design parameters of NAND flash storage devices (NFSDs) and analyzes the characteristics of various synthesized and real traces and their interaction with design parameters. Our research shows that optimizing design parameters depends heavily on the characteristics of applications. The main contribution of this research is to understand the effects of low-level specifications of NFM, e.g. cell type, page size, and block size, on system-level metrics such as performance, cost, and power consumption in various applications with different characteristics, e.g. request length, update ratios, read-and-modify ratios. Experimental results show that the optimized page and block size can achieve up to 15 times better performance than the conventional NFM configuration in various applications. The results can be used to optimize the system-level objectives of a system with specific applications, e.g. embedded systems with NFM chips, or predict the future direction of NFM.

• BMB Reports
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• 제53권4호
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• pp.191-205
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• 2020

The unexpected pandemic set off by the novel coronavirus 2019 (COVID-19) has caused severe panic among people worldwide. COVID-19 has created havoc, and scientists and physicians are urged to test the efficiency and safety of drugs used to treat this disease. In such a pandemic situation, various steps have been taken by the government to control and prevent the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). This pandemic situation has forced scientists to rework strategies to combat infectious diseases through drugs, treatment, and control measures. COVID-19 treatment requires both limiting viral multiplication and neutralizing tissue damage induced by an inappropriate immune reaction. Currently, various diagnostic kits to test for COVID-19 are available, and repurposing therapeutics for COVID-19 has shown to be clinically effective. As the global demand for diagnostics and therapeutics continues to rise, it is essential to rapidly develop various algorithms to successfully identify and contain the virus. This review discusses the updates on specimens/samples, recent efficient diagnostics, and therapeutic approaches to control the disease and repurposed drugs mainly focusing on chloroquine/hydroxychloroquine and convalescent plasma (CP). More research is required for further understanding of the influence of diagnostics and therapeutic approaches to develop vaccines and drugs for COVID-19.

• 한국정보과학회논문지:시스템및이론
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• 제30권12호
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• pp.724-735
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• 2003

최근의 고성능 슈퍼스칼라 프로세서에서는 명령어 수준 병렬성(Instruction-Level Parallelism, ILP)의 장애가 되는 명령어 간의 데이타 종속관계를 극복하기 위해 명령의 결과 값을 미리 예측하여 종속 명령들을 모험적으로 실행한다. 이러한 값 예측을 사용한 모험적 실행으로 성능은 향상되나 값 예측 테이블의 빈번한 참조와 갱신으로 부가적인 전력 소모를 요구한다. 본 논문에서는 값 예측으로 인한 성능향상과 부가적인 전력소모 간의 관계를 측정 분석한다. 또한 확신 카운터(confidence counter)를 사용한 값 예측 시도의 조정으로 모험적 실행의 정도를 조절하고, 예측 성공률이 높은 유용한 명령들만을 선택적으로 예측하여 성능을 유지하면서 부가 전력소모를 줄인다. 제안된 방식의 검증을 위해 사이클 수준 시뮬레이터에 전력소모 모델을 결합하여 프로세서의 기능수준 동작뿐만 아니라 프로세서의 전체 전력소모 및 사이클 당 전력소모도 측정할 수 있는 도구를 개발하여 검증한다.

• Archives of Plastic Surgery
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• 제42권5호
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• pp.532-543
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• 2015

Capsular contracture is the most common complication following implant based breast surgery and is one of the most common reasons for reoperation. Therefore, it is important to try and understand why this happens, and what can be done to reduce its incidence. A literature search using the MEDLINE database was conducted including search terms 'capsular contracture breast augmentation', 'capsular contracture pathogenesis', 'capsular contracture incidence', and 'capsular contracture management', which yielded 82 results which met inclusion criteria. Capsular contracture is caused by an excessive fibrotic reaction to a foreign body (the implant) and has an overall incidence of 10.6%. Risk factors that were identified included the use of smooth (vs. textured) implants, a subglandular (vs. submuscular) placement, use of a silicone (vs. saline) filled implant and previous radiotherapy to the breast. The standard management of capsular contracture is surgical via a capsulectomy or capsulotomy. Medical treatment using the off-label leukotriene receptor antagonist Zafirlukast has been reported to reduce severity and help prevent capsular contracture from forming, as has the use of acellular dermal matrices, botox and neopocket formation. However, nearly all therapeutic approaches are associated with a significant rate of recurrence. Capsular contracture is a multifactorial fibrotic process the precise cause of which is still unknown. The incidence of contracture developing is lower with the use of textured implants, submuscular placement and the use of polyurethane coated implants. Symptomatic capsular contracture is usually managed surgically, however recent research has focussed on preventing capsular contracture from occurring, or treating it with autologous fat transfer.

• 한국통신학회논문지
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• 제28권1B호
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• pp.1-10
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• 2003

IEEE 802 3ah에서 표준화가 진행되고 있는 EPON은 하나의 OLT와 다수의 ONU가 수동소자에 의해 트리 구조로 연결되므로 도청, 위장, 가용성 등의 보안 위협을 포함한다 본 논문에서는 EPON에서 보안 위협으로부터 망을 보호하고 안전한 데이터 전송을 보장하기 위해 MAC 계층에서 인증 및 비밀성 서비스를 제공하는 보안 프로토콜을 설계하였다. 설계된 보안 프로토콜은 효율적인 키관리를 위하여 공개키 기반 인증 및 키관리 프로토콜을 이용하며, 비밀성 서비스를 위하여 최근 표준화된 AES의 Rijndael 알고리즘을 채택하였다. 제안된 인증 및 키관리 프로토콜은 인증과 공개키 교환을 동시에 수행하며, 공개 난수를 전송하여 공통의 암호키를 생성하는 안전한 프로토콜이다. 키관리의 구현을 위하여 인증 및 공개키 교환 절차, 세션키 변경 절차, 키복구 절차 등을 제안하였다. 제안된 프로토콜을 검증하기 위하여 알려진 세션키, 전향적 비밀성, 미지키 공유, 키손상 위장 등의 안전성을 분석하였다.

• 미생물학회지
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• 제50권4호
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• pp.265-274
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• 2014

장내 미생물은 사람의 장에 거주하는 미생물 집단으로 자신들의 효소를 이용해 사람에게 직접적인 에너지원이 되는 대사산물을 만들기도 하고 병원성 미생물의 침입에 대응하기도 하며 소화관의 구조와 기능유지 및 면역계의 발달에 영향을 미치는 등의 중요한 기능을 수행한다. 최근 다양한 분석기술을 통해 사람의 장에 있는 다종 및 다수의 미생물의 구성을 관찰하였고 그 결과 특정 질병을 지닌 사람의 장내 미생물 구성은 건강한 사람의 일반적인 구성과 다르다는 것을 확인하였다. 이러한 발견을 바탕으로 건강한 사람의 대변에 있는 장내 미생물을 질병을 지닌 수여자에게 이식하는 fecal microbiota transplantation (FMT) 시술이 각광을 받기 시작하였다. FMT는 장내 미생물의 구성변화로 인해 나타나는 여러 질병에 치료제로 적용할 수 있는데 특히 재발률이 높은 Clostridium difficile 감염에서 활발한 연구가 이루어지고 있다. 이 논문은 지금까지 밝혀진 장내 미생물과 관련된 질병들의 종류와 실제 질병에 FMT를 적용한 사례 등을 정리하고 장내 미생물을 이용하여 현재 연구개발 중인 치료제나 진단도구의 예를 기술함으로써 장내 미생물의 사람의 건강증진과 질병치료를 위한 차세대 생물학적 치료제로서의 가능성을 고찰하고자 한다.

• 대한원격탐사학회지
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• 제26권3호
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• pp.317-324
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• 2010

In recent years, many automatic classification approaches have been employed. An automatic classification method can be effective, time-saving and can produce objective results due to the exclusion of operator intervention. This paper proposes a classification method based on automated training for high resolution multispectral images using ancillary data. Generally, it is problematic to automatically classify high resolution images using ancillary data, because of the scale difference between the high resolution image and the ancillary data. In order to overcome this problem, the proposed method utilizes the classification results of a Landsat image as a medium for automatic classification. For the classification of a Landsat image, a maximum likelihood classification is applied to the image, and the attributes of ancillary data are entered as the training data. In the case of a high resolution image, a K-means clustering algorithm, an unsupervised classification, was conducted and the result was compared to the classification results of the Landsat image. Subsequently, the training data of the high resolution image was automatically extracted using regular rules based on a RELATIONAL matrix that shows the relation between the two results. Finally, a high resolution image was classified and updated using the extracted training data. The proposed method was applied to QuickBird and SPOT-5 images of non-accessible areas. The result showed good performance in accuracy assessments. Therefore, we expect that the method can be effectively used to automatically construct thematic maps for non-accessible areas and update areas that do not have any attributes in geographic information system.

• 한국환경농학회지
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• 제40권3호
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• pp.149-160
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• 2021

BACKGROUND: Concerns have been raised about the impact of recent high concentrations of fine dust on human health. Ammonia(NH₃) reacts with sulfur oxides and nitrogen compounds in the atmosphere to form ultrafine ammonium sulfate and ammonium nitrate (PM2.5). There is a growing need for accurate estimates of the amount of ammonia emitted during agricultural production. Therefore, in this study, ammonia emissions generated from the cultivation of leafy perilla in plastic houses were determined. METHODS AND RESULTS: Cow manure compost, swine manure compost, and poultry manure compost each at 34.6 ton ha^-1, the amount commonly used by farmers in the field, was sprayed on the soil surface. Just after spraying cow manure compost, swine manure compost, and poultry manure compost, the ammonia was periodically measured and analyzed to be 22.5 kg ha^-1, 22.8 kg ha^-1, and 85.2 kg ha^-1, respectively. The emission factors were estimated at 70.0 kg-NH₃ ton-N, 62.8 kg-NH₃ ton-N, and 234.1 kg-NH₃ ton-N, respectively. Most ammonia was released in the two weeks after application of the compost and then the amount released gradually decreased. CONCLUSION: Therefore, it is necessary to improve the emission factor through a study on the estimation of ammonia emission by type of livestock manure and major farming types such as rice fields and uplands, and to update data on the production, distribution, and sales of livestock manure.

• Investigative Magnetic Resonance Imaging
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• 제23권2호
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• pp.100-113
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• 2019

Sarcoidosis is a multisystem disease characterized by noncaseating granulomas. Cardiac involvement is known to have poor prognosis because it can manifest as a serious condition such as the conduction abnormality, heart failure, ventricular arrhythmia, or sudden cardiac death. Although early diagnosis and early treatment is critical to improve patient prognosis, the diagnosis of CS is challenging in most cases. Diagnosis usually relies on endomyocardial biopsy (EMB), but its diagnostic yield is low due to the incidence of patchy myocardial involvement. Guidelines for the diagnosis of CS recommend a combination of clinical, electrocardiographic, and imaging findings from various modalities, if EMB cannot confirm the diagnosis. Especially, the role of advanced imaging such as cardiac magnetic resonance (CMR) imaging and positron emission tomography (PET), has shown to be important not only for the diagnosis, but also for monitoring treatment response and prognostication. CMR can evaluate cardiac function and fibrotic scar with good specificity. Late gadolinium enhancement (LGE) in CMR shows a distinctive enhancement pattern for each disease, which may be useful for differential diagnosis of CS from other similar diseases. Effectively, T1 or T2 mapping techniques can be also used for early recognition of CS. In the meantime, PET can detect and quantify metabolic activity and can be used to monitor treatment response. Recently, the use of a hybrid CMR-PET has introduced to allow identify patients with active CS with excellent co-localization and better diagnostic accuracy than CMR or PET alone. However, CS may show various findings with a wide spectrum, therefore, radiologists should consider the possible differential diagnosis of CS including myocarditis, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy, amyloidosis, and arrhythmogenic right ventricular cardiomyopathy. Radiologists should recognize the differences in various diseases that show the characteristics of mimicking CS, and try to get an accurate diagnosis of CS.