• 한국자동차공학회논문집
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• 제16권6호
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• pp.176-183
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• 2008

Performance of electrostatic diesel PM filtration systems (E-DPS) with different types has been tested using the carbon particles generated by spark discharge in laboratory. Among the five electrostatic precipitators, the multiple wires cylindrical E-DPS with the highest collection efficiency and relatively lower differential pressure at the flow rate of $1\;m^3$/min, as an applicable device to diesel engine as an after treatment system, has been combined with another collection cylinder to improve the collection efficiency of diesel particulate matters generated from diesel engines. The multiple wires cylindrical E-DPS combined with the cylindrical collector showed the collection efficiency of more than 60% at the engine speed of 2,000 rpm with the engine loads of 25 and 50%.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.27-35
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• 2021

NAND flash memory-based SSD needs an internal software, Flash Translation Layer(FTL) to provide traditional block device interface to the host because of its physical constraints, such as erase-before-write and large erase block. However, because useful host-side information cannot be delivered to FTL through the narrow block device interface, SSDs suffer from a variety of problems such as increasing garbage collection overhead, large tail-latency, and unpredictable I/O latency. Otherwise, the new type of SSD, open-channel SSD exposes the internal structure of SSD to the host so that underlying NAND flash memory can be managed directly by the host-level FTL. Especially, I/O data classification by using host-side information can achieve the reduction of garbage collection overhead. In this paper, we propose a new scheme to reduce garbage collection overhead of open-channel SSD by separating the journal from other file data for the journaling filesystem. Because journal has different lifespan with other file data, the Write Amplification Factor (WAF) caused by garbage collection can be reduced. The proposed scheme is implemented by modifying the host-level FTL of Linux and evaluated with both Fio and Filebench. According to the experiment results, the proposed scheme improves I/O performance by 46%~50% while reducing the WAF of open-channel SSDs by more than 33% compared to the previous one.

• Design & Manufacturing
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• 제12권2호
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• pp.57-62
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• 2018

In diabetics, daily blood glucose testing is generally required at home, and thus, performing blood collection several times a day using a blood line is essential. Blood collection in the home and in the hospital is a source of pain and is the second most common cause of infection. In blood collecting device generally consists of four major parts: inner-case, outer case, main shaft and triger, and the most import part among those for necessary functionality is the main shaft. Filling time and injection pressure, filling balance, strain-rate analysis of change based on availability of the product. The Moldflow of FEM simulation is used for the analysis of injection molding process. In this study, aims to create a technique for injection molding and manufacturing of a main shaft of a high-performance blood-collecting apparatus capable of automatically extracting a lancet to relieve pain through depth control of the lancet.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2011년도 제43차 동계학술발표논문집 19권1호
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• pp.109-110
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• 2011

현대의 도시철도차량 시스템은 복잡하고 첨단화 되어 있으며, 상호 인터페이스 체계를 구축하고 있는 차량 유지보수시스템의 체계적인 종합관리가 필요하다. 본 연구는 무선 전송 장치를 이용하여 전동차 정보 자동 수집 장치를 도입 적용한 사례에 대한 분석 결과이다. 무선 전송 장치는 차량기지로 입고한 전동차 열차종합제어장치에 수집된 각종 정보를 무선 통신으로 데이터를 전송함으로써 유지보수 비용절감과 데이터 전송의 신뢰성 향상 효과가 있으며 이러한 무선 전송 장치를 도입 적용하여 기존의 열차정보수집 방법을 개선한 운용 사례를 제시한다.

• 정보과학회 논문지
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• 제44권8호
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• pp.767-773
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• 2017

클라우드 데이터베이스와 같은 분산 시스템 환경에서는 균일한 서비스 품질을 보장하기 위해 꼬리 응답시간을 짧게 유지하는 것이 중요하다. 본 논문에서는 카산드라 데이터베이스를 대상으로, 긴 꼬리 응답시간에 해당하는 지연이 메모리 공간 부족으로 인해 발생한다는 것을 보이며, 이러한 지연이 메모리 공간 확보를 위해 버퍼에 저장된 데이터를 저장장치에 완전히 내려쓸 때까지 카산드라가 사용자의 요청을 받지 않기 때문임을 밝힌다. 버퍼에 저장된 데이터를 내려쓰는데 걸리는 시간은 저장장치 성능에 따라 결정되므로 SSD의 가바지 컬렉션으로 인한 성능 저하가 꼬리 응답시간을 더 길게 만들고 있음을 관찰하였다. 우리는 자바가상기계에서의 가비지 컬렉션과 SSD에서의 가비지 컬렉션을 함께 수행하여 SSD의 가비지 컬렉션 비용을 숨기는, SyncGC 기법을 제안한다. 실험 결과, SyncGC 기법을 통해 꼬리 응답시간인 $99.9^{th}$와 $99.9^{th}-percentile$을 각각 31%, 36% 줄일 수 있었다.

• Journal of Korean Society for Atmospheric Environment
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• 제16권E2호
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• pp.79-84
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• 2000

The Electrostatic Precipitator is one of the most favorable device of particulate control systems because of the relatively higher collection efficiency and easier operation/maintenance. However, it requires very high initial coat especially for discharging electrodes and collecting plates. In dealing with such problems, development of optimum design can be one of the solutions. In this study, a bench-scale electrostatic precipitator was operated in terms of collection area and corona power, and its performances were analyzed focusing on collection efficiency. A result of this study, a more advanced approach for designing cost-effective precipitator by promoting corona power at a minimized collection area was proposed.

• 로봇학회논문지
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• 제17권4호
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• pp.477-483
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• 2022

In this paper, we propose waste collection vehicle system with a safety device for worker safety and an autonomous driving function. The steering system is applied as MDPS (Motor Drive Power Steering) system to control the waste collection vehicle of the internal combustion engine. Safety-related errors is prevented through redundancy brake of the integrated system and the control braking system. In order to ensure safety between workers and waste collection vehicles, work guidelines and safety devices for emergency stop in case of danger are applied to vehicles. In addition, this research is conducted on improving the working efficiency through vehicle condition monitoring system and a short-range control system for field test. This research is aimed to secure stability through demonstration and contribute to the industrialization of unmanned waste collection vehicles.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제6권1호
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• pp.17-24
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• 2017

이동식 저장매체가 널리 보급됨에 따라 중요한 정보가 이동식 저장매체에 보관되는 경우가 많아지고 있다. 따라서 핵심적인 범죄 증거 역시 이동식 저장 매체에 존재할 가능성이 커지고 있으며 압수 수색 현장에서 이동식 저장 매체는 반드시 수집해야 할 대상이 되었다. 이동식 저장매체를 증거물로 획득한 경우 하드웨어 기반의 이미징 장비나 쓰기방지장치를 동반한 포렌식 소프트웨어를 통해 이미징 작업을 진행한다. 하지만 이런 장비의 경우 고가일 뿐만 아니라 현장에서 고장으로 인해 급하게 사용할 수 없는 경우를 배제할 수 없다. 또한 실험을 통해 확인한 결과 보안 USB 혹은 백신 USB의 경우 하드웨어 기반의 이미징 장비나 쓰기방지장치에서 인식을 할 수 없는 경우를 발견하였다. 따라서 본 논문에서는 현재의 이동식 저장매체에 맞는 디지털 증거 수집절차를 제안한다.

• International Journal of Computer Science & Network Security
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• 제23권2호
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• pp.203-209
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• 2023

The paper brings across data that is utilized in the Bring Your Own Device (BYOD) status collected between February and April of 2021 across Saudi Arabia. The data set was collected using questionnaires established through online mechanisms for the respondents. In the questionnaire, personal details included five questions while seven questions addressed the working model of personal mobile devices. Six questions addressed the awareness of employees bring your own device awareness for employees comprised seven questions and two questions addressed the benefits of business achievements. In the identification of suitable respondents for the research, two approaches were applied. The research demanded that the respondents be Saudi Arabian nationals and have attained 18 years. Snowball and purposive techniques were applied in the collection of information from a wide area of Saudi Arabia while employing social media approaches that include the use of WhatsApp and emails in the collection of data. The approach ensured the collection of data from 857 respondents used in the identification of the status as well as issues across the BYOD environment and accompanying solutions. The data was also used in the provision of awareness in the community through short-term courses, cyber security training and awareness programs. The results of the research are therefore applicable to the context of the Saudi Arabian country that is currently facing issues in dealing with the application of personal devices in the work environment.

• 한국컴퓨터정보학회논문지
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• 제23권9호
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• pp.107-112
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• 2018

Smart livestock has been proposed as a solution to increase farmers' income and new recruitment of livestock farmers. In this paper, a standardization Plan of breeding management device and collected information for smart livestock cattle was proposed. l Sophisticatedly, basic information will be established for all six types of livestock breeding management device: military automatic feeder, calf automatic feeder, smart milk cooler, feed bin to be able to measure feed residue, smart scale, and biometric information collection device. The standardization, common use, and stabilization of major livestock management device and collected information were suggested to solve the problems caused by in existing breeding management device.