This paper is to investigate the micro-behavior of the double-span beams with WUF-W seismic connection under combined axial tension and moment and to propose the rational rotational capacity of it for progressive collapse-resistant analysis and design addressing the stress and strain transfer mechanism. To this end, the behavior of the double-span beams under the column missing event is first investigated using the advanced nonlinear finite element analysis. The characteristics of fracture indices of double-span beams with WUF-W connection under combined axial tension and flexural moment are addressed and then proposed the rational rotational capacity as the basic datum for the progressive collapse-resistant design and analysis. The distribution of fracture indices related to stress and strain for the double-span beams is investigated based on a material and geometric nonlinear finite element analysis. Furthermore, the micro-behavior for earthquake and progressive collapse is explicitly different.

PURPOSES: This study is to estimate nondestructive strength equation based on probability for bridges using field test data. METHODS: In this study, a series of the field inspection and the test have been performed on 297 existing bridges, in order to evaluate the bridges, based on the test results of the in-depth inspection, and the estimated strengths by means of the nondestructive strength equations are analyzed and compared with results of the core specimen strengths. RESULTS: According to results of analyses, In case of standard design compressive strength of concrete is 18MPa, 21MPa, similar reliability of RILEM equation were 0.89~0.90, but in case of standard design compressive strength of concrete is 35MPa, 40MPa were 0.4~0.56. According to standard design compressive strength of concrete is 40MPa, similar reliability of ultrasonic pulse velocity method equation were 0.56. CONCLUSIONS: RILEM equation had high similar reliability than other equation in case of standard design compressive strength of concrete is 18MPa, 21MPa, but had low similar reliability than other equation in case of standard design compressive strength of concrete is 35MPa, 40MPa. and ultrasonic pulse velocity method equation had low similar reliability than other equation in case of standard design compressive strength of concrete is 40MPa.

Three kinds of STS304-Zr alloys were fabricated by varying the Zr content, and their microstructure and fracture properties were analyzed. Moreover, we performed heat treatment to improve their properties and studied their microstructure and fracture properties. The microstructure of the STS304-Zr alloys before and after the heat treatment process consisted of α-Fe and intermetallics: Zr(Cr, Ni, Fe)2 and Zr6Fe23. The volume fraction of the intermetallics increased with an increasing Zr content. The 11Zr specimen exhibited the lowest hardness and fine dimples and cleavage facets in a fractured surface. The 15Zr specimen had high hardness and fine cleavage facets. The 19Zr specimen had the highest hardness and large cleavage facets. After the heat treatment process, the intermetallics were spheroidized and their volume fraction increased. In addition, the specimens after the heat treatment process, the Laves phase (Zr(Cr, Ni, Fe) 2) decreased, the Zr6Fe23 phase increased and the Ni concentration in the intermetallics decreased. The hardness of all the specimens after the heat treatment process decreased because of the dislocations and residual stresses in α-Fe, and the fine lamellar shaped eutectic microstructures changed into large α-Fe and spheroidized intermetallics. The cleavage facet size increased because of the decomposition of the fine lamellarshaped eutectic microstructures and the increase in spheroidized intermetallics.

최근 전체산업에서 차지하는 서비스분야의 비중이 높아짐에 따라 자신이 실제 느끼는 감정과는 다른 표현을 하며 일해야 하는 감정노동자들의 고충이 사회적 이슈로 부각되고 있다. 이러한 감정노동자들은 고객들에게 심한 모욕과 비인격적인 대우를 받아도 조직이 정한 감정규칙을 준수하여 항상 친절한 응대 와 태도를 유지하도록 요구받고 있다. 이로 인해 감정노동자들은 심한 심리적 불안과 스트레스에 직면하고 있으며 이는 각종 질환에 노출되게 한다. 이러한 상황에서 감정노동자들의 직무불만족으로 인해 이직률이 증가하고 있는 실정이다. 이에 본 연구에서는 서비스 종사원의 감정노동전략을 표면행동과 내면행동으로 구분하여 감정부조화에 미치는 영향을 살펴보고, 감정부조화가 직무불만족에 미치는 영향과 직무 불만족이 파괴적인 반응행동인 태만행동과 이탈행동에 미치는 영향을 살펴보고자 한다. 또한 감정표현규칙 몰입이 감정노동과 감정부조화의 관계를 어떻게 조절하는지를 살펴보고자 한다. 이를 위해 서비스업에 종사하는 감정노동자들을 대상으로 설문조사를 실시하였으며 총 380부의 설문지가 배포되었고, 불성실한 응답을 제외한 377부의 설문지가 분석에 활용되었다. 실증분석 결과는 다음과 같다. 첫째, 표면행동은 감정부조화에 정(+)의 유의적인 영향을 미치고 내면행동은 감정부조화에 부(-)의 유의적인 영향을 미치는 것으로 나타났다. 둘째, 감정부조화는 직무불만족에 정(+)의 유의적인 영향을 미치며 셋째, 직무불만족은 태만행동과 이탈행동에 모두 정(+)의 유의적인 영향을 미치는 것으로 나타났다. 넷째, 감정노동이 감정부조화와 직무불만족을 이중매개로 태만행동과 이탈행동에 영향을 미치고 있음이 확인되었다. 마지막으로, 감정표현규칙 몰입이 높을수록 내면행동은 감정부조화에 미치는 효과가 유의하게 나타났으나 표면행동은 유의하게 나타나지 않아 감정표현규칙 몰입의 조절효과가 일부만 확인되었다. 이러한 연구결과를 토대로 이론적 및 실무적 시사점과 향후과제를 제시하였다.

PURPOSES : A geo-grid pavement, e.g., a stress-absorbing membrane interlayer (SAMI), can be applied to an asphalt-overlay method on the existing surface-pavement layer for pavement maintenance related to reflection cracking. Reflection cracking can occur when a crack in the existing surface layer influences the overlay pavement. It can reduce the pavement life cycle and adversely affect traffic safety. Moreover, a failed overlay can reduce the economic value. In this regard, the objective of this study is to evaluate the bonding properties between the rigid pavement and a SAMI by using the direct shear test and the pull-off test. The predicted fractural energy functions with the shear stress were determined from a numerical analysis of the moving average method and the polynomial regression method. METHODS : In this research, the shear and pull-off tests were performed to evaluate the properties of mixtures constructed using no interlayer, a tack-coat, and SAMI with fabric and without fabric. The lower mixture parts (describing the existing pavement) were mixed using the 25-40-8 joint cement-concrete standard. The overlay layer was constructed especially using polymer-modified stone mastic asphalt (SMA) pavement. It was composed of an SMA aggregate gradation and applied as the modified agent. The sixth polynomial regression equation and the general moving average method were utilized to estimate the interlayer shear strength. These numerical analysis methods were also used to determine the predictive models for estimating the fracture energy. RESULTS: From the direct shear test and the pull-off test results, the mixture bonded using the tack-coat (applied as the interlayer between the overlay layer and the jointed cement concrete) had the strongest shear resistance and bonding strength. In contrast, the SAMI pavement without fiber has a strong need for fractural energy at failure. CONCLUSIONS : The effects of site-reflection cracking can be determined using the same tests on cored specimens. Further, an empiricalmechanical pavement-design analysis using the finite-element method (FEM) must be done to understand the appropriate SAMI application. In this regard, the FEM application analysis and bonding property tests using cored specimens from public roads will be conducted in further research.

As an endemic species in Korea Adenophora erecta S. Lee, Joongku Lee et S. Kim is distributed in a restricted area of Ulleung island. In this study, we confirmed finding only about 60 individuals in Taeha-ryeung in an area measuring 900 m² in size. These data together with previously collected data indicate that this species is in the “Critically Endangered (CR)” category based on taxon evaluation criteria of the IUCN. We propagated this species using seeds of transplanted plant from a site where this plant was first found. The best seed germination was observed in a batch treated with GA3 (500 mg/L) under the sun light and the best plant growth was observed in a bed of nursery soil and rough-sand soil (1:1). The original habitat of A. erecta in Sukpo-dong was successfully restored by transplantation of the propagated young plants.

Plant physiological indices for Euryale ferox Salisb. an endangered aquatic plant from Gyeongsan Province, were analyzed in this study. The NDVI (Normalized Difference Vegetation Index) was highest at 0.820 in Dongguji and lowest at 0.592 in Dongjaji; the SR (Simple Ratio) index was highest at 10.240 in Dongguji and lowest at 4.312 in Dongjaji; and the PRI (Photochemical Reflectance Index) was highest at 0.039 in Dongguji and lowest at −0.036 in Dongjaji. The CRI1 (Carotenoid Reflectance Index 1) index was in Sahwaji and Waji at 8.881 and 12.988, respectively, and the CRI2 (Carotenoid Reflectance Index 2) index was highest at 7.889 in Sahwaji and lowest at 11.889 in Dongjaji.

표층용 아스팔트 혼합물은 공극률 4%로 다져졌을 때 가장 우수한 공용성을 발휘하는 것으로 알려져 있어 밀입도 아스팔트 혼합물은 배합설계시 4%의 공극률이 얻어지는 아스팔트 함량을 최적아스팔트 함량(optimum asphalt content: OAC)으로 결정한다. 그리고 현장에서는 이 밀도의 96% 이상의 다짐도가 얻어지도록 공극률 6∼7%로 다짐한다. 하지만 이 경우 아스팔트 포장으로의 수분 침투방지를 보장할 수 없어 교량포장의 경우 상판에 방수 처리를 하도록 요구하고 있다. 따라서 아스팔트 포장의 공극률을 0%에 가깝도록 다짐하면서도 공용성을 잘 유지할 수 있다면 방수 처리공정을 생략할 수 있고 포장의 수명도 보장 할 수 있어 일거양득일 것이다. 이에 공극률이 0에 가까우면서도 아스팔트 포장으로서의 특성을 유지할 수 있도록 하기 위해서는 바인더특성을 강화하고 그에 맞도록 골재 입도를 조정하는 것이 필요하다. 본 연구에서는 이렇게 공극률이 0에 가깝도록 개발된 무공극 아스팔트 콘크리트의 중요특성 중 하나인 휨 모드에서의 저온특성으로 유사파괴인성(pseudo fracture toughness: PFT)을 구하여 비교평가 하였다. 이를 위해 보 공시체를 제조하고 영하의 저온에서 3점 휨 시험을 통해 얻어진 하중-처짐 곡선에서 PFT를 구하고 이를 일반 13mm 밀입도 아스팔트(dense-graded asphalt: DGA) 혼합물을 비롯한 개질 SMA 혼합물 등과 비교하였다. 그 결과 무공극 아스팔트 혼합물의 유사파괴인성이 DGA의 4배 이상이 되는 등 가장 우수한 것을 확인 하였다. 이는 고성능의 바인더(PG 82-34)와 그에 맞는 입도조정 때문에 저온 하에서 가장 우수한 파괴인성을 보인 것으로 추정된다. 따라서 큰 균열저항성이 요구되며 방수가 필요한 교면포장 등에 사용할 경우 우수한 성능을 발휘 할 수 있을 것으로 판단된다.

목 적 : 침습성 눈물막파괴시간(TBUT, invasive tear break-up time)과 비침습성 눈물막파괴시간 (NIBUT, noninvasive tear break-up time) 검사법의 정확도를 비교하고자 하였다. 방 법 : 안질환이 없으며 굴절교정수술을 받지 않은 20대 대학생 56명(112안)을 대상으로 TBUT는 Fluorescein strip을 사용하여 측정하였고, NIBUT는 Keratograph 5M(K5M), Wavefront Analyzer (KR-1W), Auto refractor keratometer(KR-8100P)을 사용하여 측정하였다. 건성안 감별(screening) 기준 은 OSDI(ocular surface disease index) 설문지를 사용하였다. 각 측정값의 일치도 분석은 Bland & Altman Plot을 사용하여 확인하였고, 검사값의 정확도는 ROC(receiver operating characteristic) curve를 이용하여 민감도(sensitivity) 및 특이도(specificity), AUC(area under the curve), cut-off 값을 비교하여 분석하였다. 결 과 : TBUT는 NIBUT보다 유의하게 짧았고(p<0.05), KR-1W, KR-8100P, K5M으로 측정한 NIBUT 값들은 서로 유의한 차이가 없었다(F=2.69, p=0.06). NIBUT 검사값은 서로 중등도의 상관성을 보였지만 (r=0.36,0.44,0.35), TBUT는 K5M로 측정한 NIBUT와 상관성이 있었다. 검사법 상호간의 일치도 분석에서 TBUT와 NIBUT는 차이가 있었고, NIBUT 값들은 상호간 차이가 없었다. 건성안 유무 감별에 대한 민감도와 특이도는 각각 TBUT 검사법에서 25%, 80%, KR-1W 검사법에서 50%, 69%, KR-8100P 검사법에서 86%, 34%, K5M 검사법에서 31%, 82%로, 민감도는 KR-8100P 검사법이 가장 높았고, 특이도는 K5M 검사법이 가장 높았다. 결 론 : NIBUT 검사법은 TBUT 검사법보다 정확도가 높고, 검사법 상호간의 일치도가 우수하며, 건성안 감별에 KR-8100P 측정값이 유용하게 사용될 수 있을 것으로 사료된다.

Recently, for efficiency increase of the wind turbine tower, turbine has been enlarged and installation location has been transferring to offshore. The importance of the support structure is emphasized when a wind turbine tower is installed on offshore. The support structure is influenced not only by the system operating loads but also by various marine condition loads. Accurate and safe design is essential because the connection between the support structure and the wind tower can be relatively fragile. In particular, the type of foundation pile and sleeve grout connection were adapted from DNV, API, and ISO that are typically used for wind towers, and they have been continuously studied by many researchers. However, the experimental results by researchers are different from the design equations, and it needs to modify the formula according to connection properties and material. Therefore, this study investigates the design equation presented in existing design criteria and the results of research conducted by existing researchers, and analyzes ultimate strength and failure modes.

PURPOSES : This paper presents a comparison study between dynamic and static analyses of falling weight deflectometer (FWD) testing, which is a test used for evaluating layered material stiffness. METHODS: In this study, a forward model, based on nonlinear subgrade models, was developed via finite element analysis using ABAQUS. The subgrade material coefficients from granular and fine-grained soils were used to represent strong and weak subgrade stiffnesses, respectively. Furthermore, the nonlinearity in the analysis of multi-load FWD deflection measured from intact PCC slab was investigated using the deflection data obtained in this study. This pavement has a 14-inch-thick PCC slab over finegrained soil. RESULTS: From case studies related to the nonlinearity of FWD analysis measured from intact PCC slab, a nonlinear subgrade modelbased comparison study between the static and dynamic analyses of nondestructive FWD tests was shown to be effectively performed; this was achieved by investigating the primary difference in pavement responses between the static and dynamic analyses as based on the nonlinearity of soil model as well as the multi-load FWD deflection. CONCLUSIONS : In conclusion, a comparison between dynamic and static FEM analyses was conducted, as based on the FEM analysis performed on various pavement structures, in order to investigate the significance of the differences in pavement responses between the static and dynamic analyses.

At modern mechanical and automotive industry, the material with light weight proceeds in order to thr environmental issue and high performance. Machine part is fastened with numbers of bolts and nuts. Generally, the metal part at mechanical structure is fastened with bolt and nut through puncturing. But it is difficult to puncture at CFRP with the property of fiber structure like the general metal. In this study, the fracture behavior is investigated by the hole and crack at the plate of the unidirectional CFRP due to ply angle. The thickness of plate is 2 mm. Two laminates with the varied ply angles are layered and eight plies are made. The hole is placed at the center of plate and the cracks with the length of 2 mm are generated on both left and right sides from the hole. The finite element program of ANSYS is carried out in order to analyze the CFRP with fiber layer. As analysis, the maximum reaction force and equivalent stress are investigated due the angle of ply. The reaction force in case of the stacking angle of 90° is shown to be greatest among all specimens.

Columns in existing reinforced concrete structures that are designed and constructed without considering seismic loads generally exhibit widely spaced transverse reinforcements without using seismic hooks. Due to the insufficient reinforcement details in columns compared to the reinforcement requirements specified in modern seismic codes, brittle shear failure is likely to occur. This may lead to sudden collapse of entire structure during earthquakes. Adequate retrofit strategy is required for these columns to avoid such catastrophic event. In order to do so, behavior of columns in existing reinforced concrete structures should be accurately predicted through computational analysis. In this study, an analytical model is proposed for accurately simulating the cyclic behavior of shear critical columns. The parameters for backbone, as well as pinching and cyclic deterioration in strength and stiffness are calibrated using test data of column specimens failed by shear.

Purpose of this study is to investigate structural behavior of the rectangular hollow column with various transverse reinforcement details. Experimental variables are diameter, arrangement details and lateral spacing of cross tie. A total of 66 column specimens have been prepared and tested under axial compressive load. Test results showed that behaviors of column specimens were different depending on the cross tie details. Specimens with cross tie wrapping longitudinal steel and transverse steel have greater strength and ductility than specimens with cross tie wrapping the longitudinal steel.

This study mainly evaluate the aseismic performance of the existing intake tower structure, which is one of the national important infra structures, on the basis of the refined finite element (FE) analysis results. The realistic evaluation for structural damage was conducted by using the nonlinear material model that takes tension and compression strength of deteriorate concrete into consideration during FE modeling. In addition, not only tension crack but also compression crushing was analyzed by utilizing field contour functions provided in the program during nonlinear dynamic analyses when peak ground acceleration (PGA) occurred. After observing FE analysis results, it can be shown that the damage of the intake tower is the most likely to occur at the water level and the base support.

In order to provide the basis data for broad use and safe design of carbon fiber reinforced plastic, this paper aims at investigating the fracture behavior on CFRP specimen composed of one directional fiber through three point bending test. On the basis of experimental result, the improvement of composite layer specimen can be secured with the other data to compare the existing specimen. The fracture behavior happened at the experimental procedure is investigated in this study. The maximum loads of 1200 N, 1700N and 1600N are shown respectively at the specimens with the layer angles of 30°, 45° and 60°. The highest load is shown at the layer angle of 60° among all specimens and the longest displacement is maintained until each of the layer structure is broken down. The fracture due to the force applied from the outside can be prevented by applying the result of this study to the real structure. As structural safety can be evaluated and anticipated through this study, it is thought that the safe design is devoted.