• Journal of Information Processing Systems
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• 제20권1호
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• pp.85-92
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• 2024

In recent years, Bitcoin and Ethereum have witnessed a surge in trading activity, driven by venture capital investment and funding through initial coin offerings (ICOs) and initial exchange offerings (IEOs). This heightened interest has led to kickstarting a vibrant ecosystem for blockchain development. The total number of cryptocurrencies listed on CoinMarketCap.com has reached 2,274 highlights how dynamic and wide blockchain development landscape has grown. In blockchain development, new blockchain projects are being created by forking blockchains inspired by major cryptocurrencies such as Bitcoin and Ethereum. These projects aim to address the perceived shortcomings and improve existing technologies. Altcoins, representing these alternative cryptocurrencies, are an ongoing industry effort to improve performance and security with enhancement proposals such as Bitcoin Improvement Proposals (BIP), Ethereum Improvement Proposals (EIP), and EOSIO Enhancement Proposals (EEP). With competitive attempts to improve blockchain performance and security, an ongoing performance race between various blockchains has taken shape, each claiming its own performance advantages. In this paper, we describe the transactions contained in the blocks of each representative blockchain, and find the factors that affect the transactions per second (TPS) through transaction processing and block generation processes, and suggest their relationship with scalability.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제18권3호
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• pp.51-59
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• 2012

Over a past century, the continuity in post-earthquake serviceability of medical facilities has been demonstrated to be essential for sustaining a society and/or a nation stable. However, not many countries including Korea have paid appropriate attention to such a lesson learned from the previous experiences of the countries located in high seismicity for various reasons, one of which may be the lack of social consensus in allocating a portion of the resources to the earthquake preparedness. As a result, an earthquake-related policy might have been pushed away out of the list of priority in the government agenda. Therefore, the present paper attempts to persuade the public general, experts and government officials together to seek a way to upgrade the seismic safety of the country a step forward by enhancing the seismic performance of medical facilities. For this the framework of seismic design codes and standards for medical facilities, and Californian experience in managing the seismic performance enhancement program and U.S.-Italian collaborative study to improve the seismic safety of Italian hospitals are reviewed. Finally, a list of further researches and practices to perform for seismic enhancement of medical facilities in Korea are suggested.

• 동력기계공학회지
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• 제13권4호
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• pp.56-61
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• 2009

In recent years, since the continuing increase in the capacity in personal computer such as the optimal performance, high quality and high resolution image, the computer system's components produce large amounts of heat during operation. This study analyzes and investigates the ability and efficiency of a cooling system inside a computer by means of central processing unit (CPU) and power supply cooling fan. This research was conducted to enhancement of efficiency of the cooling system inside the computer by making a structure which produces different air pressures in an air inflow tube. Consequently, when temperatures of the CPU and room inside computer were compared with a general personal computer, temperatures of the tested CPU, the room and the heat sink were as low as $5^{\circ}C$, $2.5^{\circ}C$ and $7^{\circ}C$ respectively. In addition to, revolution per minute (RPM) was shown as low as 250 after 1 hour operation. This research explored the possibility of enhancing the effective cooling of high-performance computer systems.

• 한국멀티미디어학회논문지
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• 제19권1호
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• pp.10-21
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• 2016

Images taken from outdoor are degraded quality by fog or haze, etc. In this paper, we propose a method that provides the visibility improved images through fog or haze removal. We proposed haze removal method that uses brightness transform based on atmospheric scatter coefficient rate with local histogram equalization. To calculate the transmission rate that indicate fog rate in original image, we use atmospheric scatter coefficient rate based on quadratic equations about haze model. And primary brightness transformed image can be obtained by using the obtained transmission rate. Also we use local histogram equalization with proposed brightness transform for effectively image visibility enhancement. Unlike existing methods, our method can process real-time with stable and effect image visibility enhancement. Proposed method use only the luminance images processed by good performance surveillance systems because it represents the real-time processing is required, black-box, digital camera and multimedia equipment is applicable. Also because it shows good performance only with the luminance images processed, Surveillance systems, black boxes, digital cameras, and multimedia devices etc, that require real-time processing can be applied.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4930-4951
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• 2018

The deep learning based speech enhancement has shown considerable success. However, it still suffers performance degradation under mismatch conditions. In this paper, an adaptation method is proposed to improve the performance under noise mismatch conditions. Firstly, we advise a noise aware training by supplying identity vectors (i-vectors) as parallel input features to adapt deep neural network (DNN) acoustic models with the target noise. Secondly, given a small amount of adaptation data, the noise-dependent DNN is obtained by using $L_2$ regularization from a noise-independent DNN, and forcing the estimated masks to be close to the unadapted condition. Finally, experiments were carried out on different noise and SNR conditions, and the proposed method has achieved significantly 0.1%-9.6% benefits of STOI, and provided consistent improvement in PESQ and segSNR against the baseline systems.

• 한국ITS학회 논문지
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• 제8권3호
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• pp.64-70
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• 2009

본 논문은 잡음에 강인한 음성인식 성능을 획득하기 위해 generalized Gamma 분포기반의 음성향상 기법을 제안한다. 우수한 음성향상을 위해서 제안된 방식에서는 generalized Gamma분포와 spectral gain floor를 이용한 음성추적 기법에 스펙트럼 최소잡음성분에 의한 희귀적인 평균 스펙트럼 값으로부터 유도되는 잡음추정을 결합하여 음질을 향상시켜 음성인식에 적용하였다. Spectral component, spectral amplitude 그리고 log spectral amplitude에 기반하여 제안된 음성향상 기법을 잡음환경에서의 음성인식에 적용하여 그 성능을 측정하였다.

• 한국안전학회지
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• 제22권1호
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• pp.24-29
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• 2007

The effectiveness of a UV(ultra violet) disinfection system depends on the characteristics of the waste water, flow conditions, the intensity of UV radiation, the amount of time the microorganisms are exposed to the radiation, and the reactor configuration. The wast water flow conditions are important factors in the design of UV disinfection system from the point of enhancement view of UV disinfection. The turbulent energy intensity in the wake by the vortex shedding are effective for UV radiation. Therewith the effectiveness of vortex generator is considered as a enhancement of UV disinfection. The experimental results presented give important evidences and explain that it is possible to predict UV disinfection performance based on flow experiments. An experimental investigation of two types of the vortex generator is presented. The qualitative and quantitative evaluations of the wake are made by flow visualization using smoke wire method and the measurement of vortex frequencies in the wind tunnel. From the experiment, following results were obtained that the delta wing type vortex generator is more effective than circular type because of the higher vortex frequencies and the smaller drag.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.204-209
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• 1999

일반적으로 신경회로망은 다중분광 영상의 카테고리 분류를 위해 많이 사용되나 다중분광 영상의 경우 카테고리간 명암도차가 얼마나지 않아 오차 수렴시간이 많이 걸리고 분류성능이 떨어진다. 이와 같은 문제점을 해결하기 위해 본 논문에서는 평활화 과정, 주된 골을 찾는 과정, 그리고 향상 과정으로 구성되는 새로운 영상 향상법을 제안하고, 제안한 방법으로 향상된 다중분광 영상을 신경회로망의 입력으로 하여 카테고리 분류하였다. 제안한 방법을 LANDSAT TM 영상에 적용한 결과 신경회로망의 오차 수렴속도가 빨라졌고, 분류 성능이 향상되었음을 확인할 수 있었다.

• 한국추진공학회지
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• 제25권4호
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• pp.19-27
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• 2021

한국형발사체용 연소기 성능 고도화를 위한 핵심기술을 검증하기 위해 고압 축소형 연소기를 개발하였다. 성능 고도화를 위한 핵심기술은 고압 연소기용 분사기 설계, 적층제조기법을 적용한 연소안정화 장치 개발, 고압 축소형 연소기 헤드 및 재생냉각 연소실 설계/제작 등이다. 고압 축소형 연소기 개발을 통해 핵심기술을 검증하였고, 이 기술들은 향후 대형 액체로켓엔진 연소기 개발에 활용될 예정이다.

• 음성과학
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• 제10권2호
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• pp.77-84
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• 2003

In this research, we seek the beginning of the speech and detect the stationary speech region using lip information. Performing running average of the estimated speech signal in the stationary region, we reduce the effect of musical noise which is inherent to the conventional MlMSE (Minimum Mean Square Error) speech enhancement algorithm. In addition to it, SFM (Spectral Flatness Measure) is incorporated to reduce the speech signal estimation error due to speaking habit and some lacking lip information. The proposed algorithm with Wiener filtering shows the superior performance to the conventional methods according to MOS (Mean Opinion Score) test.