• Fire Science and Engineering
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• v.12 no.1
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• pp.3-8
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• 1998

This study has been conducted experimentally on the effects of natural convection heat transfer characteristics for inclined flat plate with vertical fin in air. The effects of various fin length, flat plate inclined angle and Grashof number are mainly investigated The experimented results are as follows: The mean heat transfer coefficient increase according to the decrease of H/S in the various fin lengh. The mean heat transfer coefficient at H/S-0.5, 1.0, 1.5 for Gr=2.11$\times$103. $\theta$=00 increase by 107%, 43%, 15% than H/S=2.0. The mean heat transfer coefficient decrease with the increase of $\theta$ the inclined angles. The mean heat transfer coefficient at Gr=2.97$\times$103 is constant, at $\theta$= 00 for H/S=0.5 decrease by 33% than $\theta$=90$^{\circ}$. The mean heat transfer coefficient increase as Grashof as Grashof number increase. The mean heat transfer coefficient at Gr=2.31$\times$103, Gr=2.61$\times$103, Gr=2.97$\times$103 for H/S=1.0, $\theta$=0$^{\circ}$increase by 9%, 16%, 28% than Gr=2.11$\times$103.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.299-305
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• 1994

Egg distribution and mortality rate for anchovy, Engraulis japonica, and sardine, Sardinops melanosticta, during spring in the southern waters of Korea were estimated using the data from ichthyoplankton surveys conducted from March to April 1991, 1992. Anchovy and sardine eggs were found simultaneously in high density in the southwestern waters of Tsushima Island during March 1991 and late in March${\sim}$early in April 1992. Distribution areas of anchovy and sardine eggs in 1992 was extended to the middle area of the southern waters compared to 1991. Sea surface temperatures in the survey area ranged from 8.6 to $17.8^{\circ}C$. Anchovy and sardine eggs occurred with high densities between $14^{\circ}$ and $15^{\circ}C$. Instantaneous mortality coefficients were estimated to be 0.268/day for anchovy, and 0.132/day for sardine during $4{\sim}15$ March in 1991.

• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.50-58
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• 2007

In this paper, the optimum position of optical phase conjugator (OPC) and the optimal dispersion coefficients of fiber sections in $16{\times}40$ Gbps WDM system with non zero - dispersion shifted fiber (NZ-DSF) of 1,000 km are induced, in order to expand the availability of mid-span spectral inversion (MSSI) technique in long-haul multi-channel transmission systems. It is confirmed that the compensation degrees of overall WDM channels are more improved by applying the induced optimal parameters into WDM system than those in WDM system with the conventional MSSI. So it is expected that the proposed optimal parameters should alternate with the forming method of the symmetrical distributions of optical power and local dispersion with respect to OPC, which generate a serious problem in the applying OPC into multi-channels WDM system if it is not formed. It will be possible to realize the flexible system design by applying the methods proposed in this paper into the real WDM system with OPC.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.324-330
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• 2009

The objective of this study is to estimate the carbon sequestration in forest stands using KOMPSAT-2 imagery. For estimating the amount of carbon sequestration, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated by the crown width extracted from KOMPSAT-2 imagery. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the Intergovernmental Panel on Climate Change (IPCC) guideline, was used to convert the stand biomass into the amount of carbon sequestration. Thereafter, the KOMPSAT-2 imagery was classified with the segment based classification (SBC) method in order to quantify carbon sequestration by tree species. This approach, estimating the amount of carbon sequestration for certain species in stand, can be available to extend plot-based carbon sequestration to stand-based carbon sequestration.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.5
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• pp.495-501
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• 2013

This paper describes a flexible wireless telemetering system using a mesoscale cantilever sensor, which is microfabricated with a patterned thin Ni-Cu foil on a resin substrate. The dynamic validation of the sensor has been conducted in a flow. The wireless telemetry is used to obtain data regarding the oscillating flows. It is shown that the sensor is nearly independent of the environmental temperature and is suitable for application to primary healthcare and diagnostic devices. It can be easily integrated with other modules for measuring physiological parameters, e.g., blood pressure, oxygen saturation, and heart rate, to increase the convenience and reliability of diagnosis. The precision and reliability of the sensor are also dependent on the design of the analog front-end and noise reduction techniques. It is shown that the present system's minimum interval between packet transmissions is ~16 ms.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.7
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• pp.768-774
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• 2010

Reconstruction of implicit surfaces from scattered point data sets have been developed in various engineering and scientific studies. In this paper, we represent a method to construct functions of 2D point data using multi-scale kernels and show it can be applied to graphics applications needed to access data in real-time. Our approach is similar to previous work in that a set of coefficients of the functions are calculated and stored in the preprocessing stage and function values at arbitrary positions are evaluated for real-time applications, however, it is different from others in that users can choose detail levels freely in real-time processing stage. The reason why the functions implicitly supports multi-resolution results from the mathematical properties of multi-scale kernels, and proposed method can be expanded to represent multi-resolution functions of n-dimensional data.

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.951-961
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• 2011

In this paper, we propose a Bayesian inference using the Markov Chain Monte Carlo(MCMC) method for the zero inflated negative binomial(ZINB) regression model. The proposed model allows the regression model for zero inflation probability as well as the regression model for the mean of the dependent variable. This extends the work of Jang et al. (2010) to the fully defiend ZINB regression model. In addition, we apply the proposed method to a real data example, and compare the efficiency with the zero inflated Poisson model using the DIC. Since the DIC of the ZINB is smaller than that of the ZIP, the ZINB model shows superior performance over the ZIP model in zero inflated count data with overdispersion.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.6
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• pp.391-396
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• 2016

Wicks play an important role in determining the thermal performance of heat pipes. Foam-type wicks are known to have good potential for enhancing the capillary performance of conventional types of wicks, and this is because of their high porosity and permeability. In this study, we develop an analytic expression for predicting the permeability of a foam-type wick based on extensive numerical work. The proposed correlation is based on the modified Kozeny-Carman's equation, where the Kozeny-Carman coefficient is given as an exponential function of porosity. The proposed correlations are shown to predict the previous experimental results well for an extensive parametric range. The permeability of the foam-type wick is shown to be significantly higher than that of conventional wicks because of their high porosity.

• Tuberculosis and Respiratory Diseases
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• v.66 no.1
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• pp.47-51
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• 2009

Hepatopulmonary syndrome (HPS) is characterized by a defect in arterial oxygenation that's induced by pulmonary vascular dilatation in the setting of liver disease. Some studies have shown the relationship between the presence of the HPS and the severity of liver disease, but there are only rare cases of HPS inpatient with Child-Pugh class A liver cirrhosis. We report here on a case of a 58 years-old male who suffered from progressive dyspnea for the previous few years. He was diagnosed with alcoholic liver cirrhosis 5 years previously. There was no significant abnormality on the chest radiograph and transthoracic echocardiography, but the arterial blood gas analysis revealed severe hypoxemia. Contrast-enhanced transesophageal echocardiograpy with agitated saline demonstrated a delayed appearance of microbubbles in the left cardiac chambers. Thus, he was finally diagnosed with HPS. This case suggests that we should consider HPS when a patient with compensated liver cirrhosis has unexplained dyspnea.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.121-124
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• 2001

음성 합성기의 합성음의 자연감을 높이기 위해 자연음에 내재하는 정확한 운율 법칙을 구하여 음성합성 시스템에서 이를 구현해 주어야 한다 무제한 어휘 음성합성 시스템의 문-음성 합성기에서 필요한 운율 법칙은 언어학적 정보를 이용해 구하거나, 자연음에서 추출하고 있다 그러나 추출한 운율 법칙이 자연음에 내재하는 모든 운율 법칙을 반영하지 못했거나, 잘못 구현되는 경우에는 합성음의 자연성이 떨어지게 된다. 이런 점을 고려하여 본 논문에서는 한국어 자연음을 분석하여 추출한 운율 정보를 인공 신경망이 학습하도록 하고 훈련을 마친 인공 신경망에 문장을 입력하고, 출력으로 나오는 운율 정보와 자연음의 운율 정보를 비교한 결과 제안한 인공 신경망이 자연음에 내재하고 있는 운율을 학습할 수 있음을 알 수 있었다. 운율의 3대 요소는 피치 , 지속시간, 크기의 변화이다. 제안한 인공 신경망이 한국어 문장의 음소 열을 입력으로 받아들이고, 각 음소의 지속시간에 따른 피치변화와 크기 변화를 출력으로 내보내면 자연음을 분석해 구한 각 음소의 운율 정보인 목표 패턴과 출력 패턴 의 오차를 최소화하도록 인공 신경망의 가중치를 조절할 수 있도록 설계하였다. 지속시간에 따른 각 음소의 피치와 크기 변화를 학습시키기 위해 피치 및 크기 인공 신경망을 구성하였다. 이들 인공 신경망을 훈련시키기 위해 먼저 음소 균형 문장 군을 구축하여야 하고, 이들 언어 자료를 특정 화자가 일정 환경에서 읽고 이를 녹음하여 , 분석하여 구한운율 정보를 운율 데이터베이스로 구축하였다. 문장 내의 각 음소에 대해 지속 시간과 피치 변화 그리고 크기 변화를 구하고, 곡선 적응 방법을 이용하여 각 변화 곡선에 대한 다항식 계수와 초기 값을 구해 운율 데이터베이스를 구축한다. 이 운율 데이터베이스의 일부는 인공 신경망을 훈련시키는데 이용하고, 나머지로 인공 신경망의 성능을 평가하여 인공 신경망이 운율 법칙을 학습할 수 있었다. 언어 자료의 문장 수를 늘리고 발음 횟수를 늘려 운율 데이터베이스를 확장하면 인공 신경망의 성능을 높일 수 있고, 문장 내의 음소의 수를 감안하여 인공 신경망의 입력 단자의 수는 계산량과 초분절 요인을 감안하여 결정해야 할 것이다