• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.8
• /
• pp.1803-1813
• /
• 1997

The goal of image restoration is to remove the degradations in a way that the resrored image will best approximate the original image. This can be done by the iterative regularized image restoration method. In any iterative image restoration algorithm, using a "better" termination rule results in both "better" quality of ther restored image and "less" computation, and hence, "faster" and "simp;er" practical system. Therefore, finding a better termmination rule for an iterative image restoration algorithm has been an interesting and improtant question for many researchers in the iterative image restoration. In these reasons, the new termination rule using the estimated distance between the original image and the restored image is proposed inthis paper. Noise suppression parameter(NSP) and the rule for estimating NSP with the noise variance are also proposed. The experimental results shows that the proposed termination rule is superior to the conventional methods.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.2
• /
• pp.380-389
• /
• 2005

The Goldschmidt iterative algorithm for a floating point divide calculates it by performing a fixed number of multiplications. In this paper, a variable latency Goldschmidt's divide algorithm is proposed, that performs multiplications a variable number of times until the error becomes smaller than a given value. To calculate a floating point divide '$\frac{N}{F}$', multifly '$T=\frac{1}{F}+e_t$' to the denominator and the nominator, then it becomes ’$\frac{TN}{TF}=\frac{N_0}{F_0}$'. And the algorithm repeats the following operations: ’$R_i=(2-e_r-F_i),\;N_{i+1}=N_i{\ast}R_i,\;F_{i+1}=F_i{\ast}R_i$, i$\in${0,1,...n-1}'. The bits to the right of p fractional bits in intermediate multiplication results are truncated, and this truncation error is less than ‘$e_r=2^{-p}$'. The value of p is 29 for the single precision floating point, and 59 for the double precision floating point. Let ’$F_i=1+e_i$', there is $F_{i+1}=1-e_{i+1},\;e_{i+1}',\;where\;e_{i+1}, If '$[F_i-1]<2^{\frac{-p+3}{2}}$ is true, ’$e_{i+1}<16e_r$' is less than the smallest number which is representable by floating point number. So, ‘$N_{i+1}$ is approximate to ‘$\frac{N}{F}$'. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications per an operation is derived from many reciprocal tables ($T=\frac{1}{F}+e_t$) with varying sizes. 1'he superiority of this algorithm is proved by comparing this average number with the fixed number of multiplications of the conventional algorithm. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a divider. Also, it can be used to construct optimized approximate reciprocal tables. The results of this paper can be applied to many areas that utilize floating point numbers, such as digital signal processing, computer graphics, multimedia, scientific computing, etc

• The KIPS Transactions:PartA
• /
• v.12A no.2 s.92
• /
• pp.95-102
• /
• 2005

The Newton-Raphson iterative algorithm for finding a floating point reciprocal which is widely used for a floating point division, calculates the reciprocal by performing a fixed number of multiplications. In this paper, a variable latency Newton-Raphson's reciprocal algorithm is proposed that performs multiplications a variable number of times until the error becomes smaller than a given value. To find the reciprocal of a floating point number F, the algorithm repeats the following operations: '$'X_{i+1}=X=X_i*(2-e_r-F*X_i),\;i\in\{0,\;1,\;2,...n-1\}'$ with the initial value $'X_0=\frac{1}{F}{\pm}e_0'$. The bits to the right of p fractional bits in intermediate multiplication results are truncated, and this truncation error is less than $'e_r=2^{-p}'$. The value of p is 27 for the single precision floating point, and 57 for the double precision floating point. Let $'X_i=\frac{1}{F}+e_i{'}$, these is $'X_{i+1}=\frac{1}{F}-e_{i+1},\;where\;{'}e_{i+1}, is less than the smallest number which is representable by floating point number. So, $X_{i+1}$ is approximate to $'\frac{1}{F}{'}$. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications per an operation is derived from many reciprocal tables $(X_0=\frac{1}{F}{\pm}e_0)$ with varying sizes. The superiority of this algorithm is proved by comparing this average number with the fixed number of multiplications of the conventional algorithm. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a reciprocal unit. Also, it can be used to construct optimized approximate reciprocal tables. The results of this paper can be applied to many areas that utilize floating point numbers, such as digital signal processing, computer graphics, multimedia scientific computing, etc.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.1
• /
• pp.22-27
• /
• 2017

$TiO_2$ films, thickness of $1{\sim}30{\mu}m$ were deposited on glass substrate at room temperature by room temperature granule spray in vacuum. The starting powder was calcinated at $600^{\circ}C$ for 4 h using $Al_2O_3$ crucible in the furnace. The particle size of the $TiO_2$, $1.5{\mu}m$ was measured by a particle size analyzer. The effect of different process parameters such as number of pass, gas flow rate and feeder voltage was studied. As the number of passes increased, the film thickness increased proportionally due to adequate kinetic energy conserved. The effect of three different flow rates (i.e. 15, 25, and 35 LPM) on deposited film was investigated. As gas flow rate increased, the film thickness increased up to 25 LPM and then decreased. Higher feeder voltage with low flow rate of 15 LPM resulted in unsufficient coating thickness due to insufficient kinetic energy. Microstructure of $TiO_2$ films was investigated by scanning electron microscope and high resolution tramission electron microscope.

• 한국체육학회지인문사회과학편
• /
• v.51 no.5
• /
• pp.639-647
• /
• 2012

The purpose of this study was to examine the effects of varied resistance training intensities and rest intervals between training sets on integral electromyography (iEMG), repetition rate, and total work. All subjects, 14 college students, were tested one repetition maximum (1RM). Then, all subjects were weekly tested with 9 practice procedures, composed of diverse intensities (60, 75, 90% of 1RM) and rest intervals (1, 3, 5 min). As results show, to maintain the same load and target repetition maximum for an untrained person, muscular power training (90% of 1RM), muscular hypertrophy training (75% of 1RM), and muscular endurance training (60% of 1RM) should be applied with 5 min or longer rest interval periods for 3 training sets. In addition, 2 training sets with 3 min rest intervals and a set with an 1 min rest interval were capable by the subjects. Thus, at least 3 min or longer rest intervals should be applied to maintain multiple training sets. In case for muscular endurance training, which requires shorter rest intervals, the intensity of exercise should be adjusted to 60% of 1RM or less. In conclusion, depending on diverse purposes of resistance training such as improving muscular power, muscular hypertrophy, or muscular endurance, appropriate exercise intensity and rest intervals should be applied.

• Journal of the Korean Geotechnical Society
• /
• v.32 no.6
• /
• pp.49-59
• /
• 2016

We develop liquefaction resistance curves, which represent the correlation between cyclic resistance ratio (CRR) and number of cycles (N) to estimate the build-up of residual excess pore pressure from simple shear tests performed for this study and also from published literature. The liquefaction curve is calculated from two models. The comparisons show that one of the models is not reliable because it underestimates CRR. The scatter of the data is shown to be significantly reduced when CRR is normalized to the resistance ratio at N = 15 ($CRR_{N=15}$). Use of the normalization is particularly useful because CRR can be easily estimated from field tests. From normalization, we propose mean, upper, and lower curves. The corresponding design equation and its parameters are also proposed. We believe that the proposed curves can be used for effective stress site response analyses and evaluation of the seismic performance of port structures.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.1
• /
• pp.188-198
• /
• 2005

The Goldschmidt iterative algorithm for finding a floating point square root calculated it by performing a fixed number of multiplications. In this paper, a variable latency Goldschmidt's square root algorithm is proposed, that performs multiplications a variable number of times until the error becomes smaller than a given value. To find the square root of a floating point number F, the algorithm repeats the following operations: $R_i=\frac{3-e_r-X_i}{2},\;X_{i+1}=X_i{\times}R^2_i,\;Y_{i+1}=Y_i{\times}R_i,\;i{\in}\{{0,1,2,{\ldots},n-1} }}'$with the initial value is $'\;X_0=Y_0=T^2{\times}F,\;T=\frac{1}{\sqrt {F}}+e_t\;'$. The bits to the right of p fractional bits in intermediate multiplication results are truncated, and this truncation error is less than $'e_r=2^{-p}'$. The value of p is 28 for the single precision floating point, and 58 for the doubel precision floating point. Let $'X_i=1{\pm}e_i'$, there is $'\;X_{i+1}=1-e_{i+1},\;where\;'\;e_{i+1}<\frac{3e^2_i}{4}{\mp}\frac{e^3_i}{4}+4e_{r}'$. If '|X_i-1|<2^{\frac{-p+2}{2}}\;'$ is true, $'\;e_{i+1}<8e_r\;'$ is less than the smallest number which is representable by floating point number. So, $\sqrt{F}$ is approximate to $'\;\frac{Y_{i+1}}{T}\;'$. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications per an operation is derived from many reciprocal square root tables ($T=\frac{1}{\sqrt{F}}+e_i$) with varying sizes. The superiority of this algorithm is proved by comparing this average number with the fixed number of multiplications of the conventional algorithm. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a square root unit. Also, it can be used to construct optimized approximate reciprocal square root tables. The results of this paper can be applied to many areas that utilize floating point numbers, such as digital signal processing, computer graphics, multimedia, scientific computing, etc.

• Journal of KIISE:Software and Applications
• /
• v.32 no.8
• /
• pp.795-807
• /
• 2005

The classical approaches for computing Live Variable Analysis(LVA) use iterative algorithms across the entire programs based on the Data Flow Analysis framework. In case of Zephyr compiler, average execution time of LVA takes $7\%$ of the compilation time for the benchmark programs. The classical LVA algorithm has many aspects for improvement. The iterative algorithm for LVA scans useless basic blocks and calculates large sets of variables repeatedly. We propose the improvement of Iterative algorithm for LVA based on used variables' upward movement. Our algorithm produces the same result as the previous iterative algorithm. It is based on use-def chain. Reordering of applying the flow equation in DFA reduces the number of visiting basic blocks and redundant flow equation executions, which improves overall processing time. Experimental results say that our algorithm ran reduce $36.4\%\;of\;LVA\;execution\;time\;and\;2.6\%$ of overall computation time in Zephyr compiler with benchmark programs.

• KSBB Journal
• /
• v.22 no.4
• /
• pp.179-184
• /
• 2007

This study introduces the characteristics and some applications of repetitive polypeptides, especially to the biomaterial, tissue engineering scaffolds, drug delivery system, and DNA separation systems. Since some fibrous proteins, which consist of repeating peptide monomers, have been reported that their physical properties are changed dramatically by means of temperature alteration or pH shifting. For that reason, fibrous protein-mimetic polypeptides, which are produced by the recombinant technology, can be applied to the diverse biological fields. Repetitive polypeptides can also be used in the bioseparation area such as DNA sequencing, because they make DNA separation possible in free-solution electrophoresis by conjugating DNA fragments to them. Moreover, artificial synthesis of repetitive polypeptides helps to demonstrate the correlations between mechanical properties and structures of natural protein polymer, which have been proven that repetitive domains are affected by the sequence of the repeating domains and the number of repeating subunits. Repetitive polypeptides can be biologically synthesized using some special cloning methods, which are represented here. Recursive directional ligation (RDL) and controlled cloning method (CCM) have been proposed as excellent cloning methods in that we can control the number of repetition in the multimerization of polypeptides and the components of repetitive polypeptides by either method.

• Bulletin of the Korean Space Science Society
• /
• 2009.10a
• /
• pp.26.3-27
• /
• 2009

한 기의 영상레이더 위성을 이용하여 동일한 촬영지역에 대해 적절한 기선벡터(Baseline)을 유지하는 두 장(scene)의 영상을 획득하여 그 지역의 정밀 표고차를 추출하는 레이더 간섭계(Interferometry) 임무를 수행하기 위해서는 반복지상궤적을 유지하도록 위성의 궤도를 주기적으로 조정해 주어야 한다. 이 연구에서는 반복지상궤적 유지 정밀도를 극대화시키기 위하여 최적의 기준궤도를 생성하고 이를 유지하기 위한 속도증분 및 궤도 조정 일정을 산출할 수 있는 궤도최적화 S/W 를 개발하였다. 이 연구의 최적 궤도 설계 문제는 다음과 같다. "시작시간 $T_0$에서 초기 접촉궤도 상태벡터 (ECEF 위치 및 속도벡터) $x_0$이고, 지상궤적반복주기 p 이후의 시간 $T_0+p$에서도 초기 접촉궤도 상태벡터와 동일한$x_0$가 되도록 궤도를 유지하려고 할 때, 여명 궤도(dawn-dusk and sun-synchronous orbit)에서 운영되는 위성의 연료소모(또는 속도증분)를 최소화시키는 가상의 궤도조정(maneuver) 횟수, 시기, 크기를 찾아라." 이 연구에서는 궤도최적화 문제를 풀기 위하여 GRACE 중력모델(GGM02C)이 적용된 수치적 방법의 위성궤도예측 알고리즘을 시스템 설계에 적용하였고, 매개변수 최적화 방법 중 구속조건이 있는 비선형 최적화 기법의 하나인 연속 2차 계획법(sequential quadratic programming)을 사용하여 해를 구하였다. 개발된 궤도최적화 S/W의 성능을 분석하기 위하여 고도 550km의 여명궤도를 돌며 지상궤적반복주기가 28일인 영상레이더 위성에 대해 적용하였다. 해석 결과를 통해, 비록 시스템의 비선형이 큼에도 불구하고 최소의 속도증분으로 정밀한 반복지상궤적이 유지됨을 알 수 있었다.