• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.862-870
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• 2010

This thesis has been researched on optimized design method for the total cross section of embankment considering the fact that the size of embankment cross section is directly related with economic efficiency when dam designing. In general, embankment cross section of fill dam is either determined by cohesion and angle of internal friction, a strength parameter of embankment materials or by permeability of embankment. Therefore the size of embankment cross section depending on strength parameter of embankment materials was determined by using MIDAS-GTS program through stress-seepage coupled analysis at the time of fill dam design. As a result, determination of embankment cross section was more affected by the size of central core and permeability rather than by slope stability by shear strength and it was revealed that in case of embankment height being over 20m, stability against infiltration and slope action could be secured only when embankment slope is at least over 1:2.5. In addition, it was also revealed that in case of making the size of central core exceeding specification standard, total cross section of embankment could be reduced considerably and at the time of embankment design, adequate size and appropriateness of embankment cross section could be determined with referring the table suggested by this study.

• Advances in Computational Design
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• 제7권1호
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• pp.69-79
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• 2022

In this research, the aeroelastic instability of a tail section manufactured from aluminum isotropic material with different shell thickness investigated. For this purpose, the two degrees of freedom flutter analytical approach are used, which is accompanied with simulation by finite element analysis. Using finite element analysis, the geometry parameters such as the center of mass, the aerodynamic center and the shear center are determined. Also, by simulation of finite element method, the bending and torsional stiffnesses for various thickness of the airfoil section are determined. Furthermore, using Lagrange's methods the equations of motion are derived and modal frequency and critical torsional/bending modes are discussed. The results show that with increasing the thickness of the isotropic airfoil section, the flutter and divergence speeds increased. Compared of the obtained results with other research, indicates a good agreement and reliability of this method.

• 한국도로학회논문집
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• 제19권1호
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• pp.63-72
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• 2017

PURPOSES : The purpose of this study is to investigate the fundamental behaviors such as stresses and deflections of the middle slab in a double-deck tunnel for the development of a middle slab design guide. METHODS : The middle slab has been divided into the following three different sections as according to its structural differences: the normal section, expansion joint section, and emergency passageway section. The normal section of middle slab represents the slab supported by brackets installed continuously along the longitudinal direction of tunnel lining. The expansion joint section refers to a discontinuity of middle slab due to the existence of a transverse expansion joint. The emergency passageway section has an empty rectangular space in the middle slab that acts as an exit in an emergency. The finite element analysis models of these three sections of middle slab have been developed to analyze their respective behaviors. RESULTS : The stresses and deflections of middle slab at the three different sections decrease as the slab thickness increases. The emergency passageway section yields the largest stresses and deflections, with the normal section yielding the smallest. CONCLUSIONS : The stress concentrations at the corners of the passageway rectangular space can be reduced by creating hunch areas at the corners. The stresses and deflections in the emergency passageway section can be significantly decreased by attaching beams under the middle slab in the passageway area.

• 분석과학
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• 제12권3호
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• pp.260-264
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• 1999

법적시료(Forensic Evidences)로 사용되는 혈흔, 정액반, 타액반 및 모발을 DNA의 분리과정 없이 FoLT (Formamide Low Temperature) PCR법으로 DNA의 특정부위를 분석하고자 하였다. FoLT PCR법으로 3종류의 STR(Short Tandem Repeat) 좌위와 성별을 확인하는 Amelogenin gene을 PCR법으로 동시에 분석하기 위하여 formamide농도와 annealing온도를 검토한 바 최적의 formamide농도는 8%(v/v)이었고 annealing온도는 $48^{\circ}C$이었다. 그리고 1% Triton X-100을 이용하여 시료를 세척한 경우에 증폭 효율이 증가하였다. 따라서 FoLT-PCR법을 이용한 경우 DNA를 분리하기 위한 전처리없이 소량의 시료를 기존의 PCR법보다 빠른 시간내에 한번의 PCR 및 전기영동으로 HumTH01, HumTPOX, HumCSF1PO 및 Amelogenin을 동시에 분석할 수 있었다.

• 보존과학연구
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• 통권20호
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• pp.5-20
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• 1999

We have analyzed the allele and genotype frequencies from 10 fractions of ancient human skeleton in 3 pieces of Jar coffin excavated from Naju Bokamni3rd tumulus by PCR amplification, high resolution polyacrylamide gelelectorphoresis and silver staining. We could isolate human genomic DNA from 3 bone fractions but the rest of them could not be used as materials due to being decayed. We could detect sex determination as male and 3 genotypes of STR system, HUMTHO1, HUMTPOX and HUMC5F1PO from the bone fraction of left side in Jar coffin 3 and see the slightly reaction suggesting the sex as male from the bone fraction of the left side in Jar coffin 2 and female from the right side in Jar coffin 3.We have also analyzed the genotype frequencies of mitochondria from the bone fractions of the left side and the right side in jar coffin 3, respectively. From the result of indetifiying at nucletide position between 16018 and 16378of the base of hyper variable region(HV1) in the control region, We can presume that the both bones have the same maternal inheritance.

• 지역연구
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• 제15권3호
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• pp.1-13
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• 1999

Since the 1990's, the most important environmental issue on the earth is characterized by "global worming problem". The United Nations Framework Convention on Climate Change (UNFCCC) plays an significant role to solve this problem on a worldwide scale. The main purpose of this paper is to analyse the impact of $CO_2$ reduction on the Daegu regional economy through 1995 regional input-output coefficients derived from the 1995 national input coefficients table by using non-survey method. The sectoral impacts on output, income, and employment were computed under the decline-unequalized assumption in final demand influenced by $CO_2$ reduction. This article has six main sections. Section 1 is an introduction to this paper. Section 2 explains briefly the derivation method of the regional technical coefficients. Section 3 describes the model building through input-output multipliers. In section 4 regional data on output, income, employment and final demand are computed to estimate the regional impacts. Section 5 deals with impact analysis on the Daegu economy. Section 6 contains a brief summary and concludintg remarks. The research findings of this study can be summarized as follows. In 1995, under the assumption of 10% decrease on an average in final demand sectors, the economy of the region studied decreased \3600 billion of output, ￦1114 billion of income, and 49919 man-years of employment. The percent ratios of each value to the total showed 9.4%, 9.7%, and 9.2%, respectively. The dominant sectors associated with impact analysis within the region are chemicals and chemical products, paper, printing and publishing, and textiles and leather, etc; nevertheless, the least dominant sector is non-metallic mineral products. products.

• 한국연소학회지
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• 제15권1호
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• pp.12-21
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• 2010

The main objective of this study was investigation of combustion instability characteristics in a lean partially premixed gas turbine dump combustor. Dynamic pressure transducers were located on combustor and inlet section to observe combustion pressure oscillation and difference at each measurement places. Also flame shape and $CH^*$ chemiluminescence were measured using a high speed ICCD camera. The combustor length was varied in order to have different acoustic characteristics from 800 to 1090 mm. The first section of this paper shows the stability map in model gas turbine combustor. And the effects of combustor length, mixture velocity in the mixing section and equivalence ratio were studied by the pressure perturbation and heat release oscillation. Also, the instability frequency and mode analysis were studied in last two sections. We observed two dominant instability frequencies in this study. Lower frequencies were obtained at lower equivalence ratio region and it was associated with a fundamental longitudinal mode of combustor length. Higher frequencies were observed in higher equivalence ratio conditions. It was related to secondary longitudinal mode of combustor and mixing section. In this instability characteristics, pressure oscillation of mixing section part was larger than pressure oscillation of combustor. As a result, combustion instability was strongly affected by acoustic characteristics of combustor and mixing section geometry.

• Fibers and Polymers
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• 제6권1호
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• pp.82-88
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• 2005

We have investigated the luster of modified cross-sectional fiber fabrics as one of the essential quality estimates for clothing development. We have confirmed an objective evaluation method, and have determined the experimental luster char­acteristics of modified cross-section fibers. The cross-section of the fibers in a fabric affects the appearance of a textile. We used the image analysis method to investigate the luster to determine the critical factors influencing the appearance of modi­fied cross-section fiber fabrics. For similarly structured textiles in a component fabric, clear differences were observed in the fabric weave, density, percentage, and total area of blobs, which is image region. Color played a decisive role in the luster of the textiles, and luster was not significantly influenced by the modified cross-section fabric weave. In addition, the degree of luster did not increase in the order plain to twill to satin for modified cross-sectional fiber fabrics. All the split-type microfi­bers exhibited higher numerical luster values (percentage of pixels, and number and total area of blobs) than sea-island microfibers did. The degree of luster of the modified cross-sectional fiber fabrics was not high at specular reflection angles.

• 대한기계학회논문집
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• 제15권6호
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• pp.1831-1838
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• 1991

본 연구에서는 와핑과 두 단면중심의 불일치에 의해 발생하는 기하중심의 이 동을 고려한 등매개변수보요소를 개발하여 스프링단면의 응력해석을 수행하고 그 결과 를 다음과 같이 검증할 것이다.우선 본 연구에 사용된 보요소가 이 두 효과를 효과 적으로 표현하고 있는지를 확인하기 위해서 간단한 비틀림실험과 비교할 것이다. 또 한 2차원문제에 대해서 입체요소를 이용한 결과와 비교하고, 원통형 스프링모델의 해 석결과를 Nagaya의 해석결과와 비교함으로써 실제 스프링해석에 효과적으로 적용될 수 있음을 보일 것이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.717-720
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• 2005

Acoustic loads generated by a rocket propulsion system cause severe random vibrations on payloads. In developing a new launch vehicle, a random vibration level must be specified before the detailed design of payloads or electronic equipments. This paper deals with prediction procedures of a random vibration level on payload section of KSLV-I. The prediction is based on statistical energy analysis. In order to verify the prediction methodology, test and analysis on a sub-scale payload section are performed. The predicted results subject to very high level of acoustic loads show a good agreement with the test results performed in the high intensity acoustic chamber. The predicted random vibration level on payload section of KSLV-I is also presented in this paper.