• 대한수학회보
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• 제51권3호
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• pp.659-666
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• 2014

Let $\mathcal{A}$ be the class of analytic functions f in the open unit disk $\mathbb{U}$={z : ${\mid}z{\mid}$ < 1} with the normalization conditions $f(0)=f^{\prime}(0)-1=0$. If $f(z)=z+\sum_{n=2}^{\infty}a_nz^n$ and ${\delta}$ > 0 are given, then the $T_{\delta}$-neighborhood of the function f is defined as $$TN_{\delta}(f)\{g(z)=z+\sum_{n=2}^{\infty}b_nz^n{\in}\mathcal{A}:\sum_{n=2}^{\infty}T_n{\mid}a_n-b_n{\mid}{\leq}{\delta}\}$$, where $T=\{T_n\}_{n=2}^{\infty}$ is a sequence of positive numbers. In the present paper we investigate some problems concerning $T_{\delta}$-neighborhoods of function in various classes of analytic functions with $T=\{2^{-n}/n^2\}_{n=2}^{\infty}$. We also find bounds for $^{\delta}^*_T(A,B)$ defined by $$^{\delta}^*_T(A,B)=jnf\{{\delta}&gt;0:B{\subset}TN_{\delta}(f)\;for\;all\;f{\in}A\}$$ where A, B are given subsets of $\mathcal{A}$.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.982-989
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• 2005

In this study, a series of laboratory tests based on 'Unit-cell concept' are performed to investigate improvement characteristics of clay ground in sand compaction pile method. Settlement reduction characteristics of composite ground and improvement characteristics of clay part could be qualified. In these procedure, the new strain-compression index($C_{\epsilon}$) of composite ground are adopted to show compressibility of composite ground according to the area replacement ratio, which is similar to the compression index($C_c$) in pure clay ground. Also, using normalization of reduction of water content in composite ground to the initial water content, improvement characteristics of clay part are investigated.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권5호
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• pp.511-518
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• 2016

The dynamic positioning system (DPS) maintains an offshore vessel's position and heading under various environmental conditions by using its own thrust. DPS is regarded as one of the most important systems in offshore vessels. So, efficient operation and maintenance of the DPS are important issues. To monitor the DPS, it is necessary to define an appropriate key performance indicator (KPI) that can express the condition of the DPS from the perspective of operational efficiency and maintenance. In this study, a new KPI for the DPS is proposed considering the efficiency of the machinery and controller, the energy efficiency, and the environmental conditions in which the DPS is operated. The KPI is defined as a function of control deviation, energy consumption, and environmental load. A normalization factor is used to normalize the effect of environmental load on the KPI. The KPI value is calculated from DPS simulation and model test data. The possibility of applying the KPI to monitoring of DPS condition is discussed by comparing the values. The result indicates the feasibility of the new KPI.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권2호
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• pp.138-145
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• 2003

Performance assessment was introduced to improvement of self-directed learning and method of assessment for differenced learning as the seventh educational curriculum is enforced. Performance assessment is overcoming limitation about problem solving ability and higher thinking abilities assessment that is problem of a written examination and get into the spotlight by way for quality of class and school normalization. But, performance assessment has problems about possibilities of assessment fault by appraisal, fairness, reliability, and validity of grading, ambiguity of grading standard, difficulty about objectivity security etc. This study proposes fuzzy performance assessment system to solve problem of the conventional performance assessment. This paper presented an objective and reliable performance assessment method through fuzzy reasoning, design fuzzy membership function and define fuzzy rule analyzing factor that influence in each sacred ground of performance assessment to account principle subject. Also, performance assessment item divides by formation estimation and subject estimation and designed membership function in proposed performance assessment method. Performance assessment result that is worked through fuzzy performance assessment system can pare down burden about appraisal's fault and provide fair and reliable assessment result through grading that have correct standard and consistency to students.

• 천문학회보
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• 제36권2호
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• pp.53.1-53.1
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• 2011

We analyze the halo and galaxy catalogs from the Millennium simulations at redshifts z=0, 0.5, 1 to determine the alignment profiles of cluster galaxies in terms of the matter density correlation coefficient and discuss a cosmological implication our result has for breaking parameter degeneracies. For each selected cluster, we measure the alignment between the major axes of the pseudo inertia tensors from all satellites within cluster's virial radius and from only those satellites within some smaller radius. Then we average the measured values over the similar-mass sample to determine the cluster galaxy alignment profile as a function of top-hat scale difference at each redshift. It is shown that the alignment profile of cluster galaxies is well approximated by a power-law of the nonlinear density correlation coefficient that is independent of the power spectrum normalization and bias factor. The alignment profile of cluster galaxies is found to have higher amplitude and lower power-law index when averaged over the larger-mass sample and to have rather weak redshift-dependence. This result is consistent with the picture that the satellite galaxies retain the memory of the external tidal fields right after merging and infalling into the clusters but they gradually lose the initial alignment tendency as the cluster's relaxation proceeds. Demonstrating that the nonlinear density correlation coefficient varies sensitively with the density parameter and neutrino mass fraction, we discuss a potential power of the cluster galaxy alignment profile as an independent probe of cosmology.

• 한국식품과학회지
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• 제26권5호
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• pp.616-621
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• 1994

한국인을 위한 식품중 유해성분의 기준설정 및 안전성 평가에 필요한 식품계수를 제안하기 위하여 $1986{\sim}90$년에 걸쳐 국민영양조사에 의한 식품섭취량과 식품수급표에 의한 공급량 자료로부터 농축산식품 원료에 대한 식품 종류별 섭취량을 최적화 하였다. 농축산물의 1인당 1일 평균 섭취량은 1.0kg으로 조정하였으며 곡류 422g, 감자류 29g, 두류 17g, 견과종실류 5g, 과일류 97g, 채소류 300g, 육류 49g, 난류 20g, 우유류 72g 이었다.

• 한국병원경영학회지
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• 제16권4호
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• pp.67-84
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• 2011

The open Hospital Attending Physician System has been discussed and operated for developing the efficiency and the substitutes for an increase in medical expenses, for overlapping investment in medical resources, and for normalization of medical delivery system. This study assessed the related factors to the acceptance and introduction of Attending Physicians on ophthalmologist. Data was collected mail response to 179 ophthalmologists in 2005. Applying multilevel logistic regression, we examined the relationship between their acknowledgment, attitude and acceptance of the open Hospital Attending Physicians System. The percentage of participation in Hospital Attending was indicated to be 3.9%. The 44.7% of all participants agreed to adopting the Hospital Attending, 33.5% of doctors are willing to participate in the future. The positive and normal attitude of physician toward the Hospital Attending is 6.6 times (95%CI 1.315, 33.138) and 55.2 times(95%CI 11.352, 268.347) more than that of negative after adjustment for other variables. Attitude was found to be the important factor influencing physicians' participation in the Attending Hospital. Thus, it is need to development and implication for the strategies that lead the practical necessity and positive attitude toward the Attending Hospital.

• 대한전자공학회논문지
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• 제20권4호
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• pp.47-54
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• 1983

DCT/DPCM 복합 감축방식(hybrid coding)에서 주요 시스템 변수에 따른 성능 변화가 평균 자승오차와 주관검사(subjective test)를 기준으로 해서 연구되었다. 검토된 시스템 변수는 DCT 변환계수의 예측상수, 블록 양자기의 평준화 계수 및 비트배정등이다. 그리고 적응식 감축방식의 특성도 비교 검토되었다. 실험결과로는 영상의 공분체 모델을 근거로 하는 비트 기정 및 적응방식이 실시간 처리에 편리할 뿐만 아니라, 낮은 비트율에서는 매우 유리한 방법임이 확인되었다.

• 한국정보처리학회논문지
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• 제4권7호
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• pp.1873-1880
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• 1997

다중 문자 환경의 문서인식 시스템에서 문자를 인식하기 전에 문자의 종류를 먼저 구분하는 것은 인식률의 향상에 중요한 요인이 된다. 각 나라의 문자는 그 문자마다 고유의 구성상의 다양한 특징을 가진다. 본 연구에서는, 문자를 구분하기 위한 방법으로 획 밀도 값을 이용하였고, 대상 문자는 한글과 영문으로 한정하였다. 다양한 형태의 활자가 사용되는 문서에 적용하기 위해 입력 데이터는 정규화 과정을 거친 후 처리되었다. 제안된 방법은 90% 이상의 높은 확률로 한영 구분이 가능함을 실험 결과로써 입증하였다.

• Tribology and Lubricants
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• 제39권2호
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• pp.61-71
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• 2023

This study proposes a procedure for designing a labyrinth seal that meets both leakage flow rate and rotordynamic performance criteria (effective damping, amplification factor, separation margin, logarithmic decrement, and vibration amplitude). The seal is modeled using a one control volume (1CV) bulk flow approach to predict the leakage flow rate and rotordynamic coefficients. The rotating shaft is modeled with the finite element (FE) method and is assumed to be supported by two linearized bearings. Geometry, material and operating conditions of the rotating shaft, and the supporting characteristics of the bearings were fixed. A single labyrinth seal is placed at the center of the rotor, and the linearized dynamic coefficients predicted by the seal numerical model are inserted as linear springs and dampers at the seal position. Seal designs that satisfy both leakage and rotordynamic performance are searched by modifying five seal design parameters using the multi-grid method. The five design parameters include pre-swirl ratio, number of teeth, tooth pitch, tooth height and tooth tip width. In total, 12500 seal models are examined and the optimal seal design is selected. Finally, normalization was performed to select the optimal labyrinth seal designs that satisfy the system performance requirements.