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        검색결과 11,249

        941.
        2022.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In existing ceramic mold manufacturing processes, inorganic binder systems (Si-Na, two-component system) are applied to ensure the effective firing strength of the ceramic mold and core. These inorganic binder systems makes it possible to manufacture a ceramic mold and core with high dimensional stability and effective strength. However, as in general sand casting processes, when molten metal is injected at room temperature, there is a limit to the production of thin or complex castings due to reduced fluidity caused by the rapid cooling of the molten metal. In addition, because sodium silicate generated through the vitrification reaction of the inorganic binder is converted into a liquid phase at a temperature of 1,000 °C. or higher, it is somewhat difficult to manufacture parts through high-temperature casting. Therefore, in this study, a high-strength ceramic mold and core test piece with effective strength at high temperature was produced by applying a Si-Na-Ti three-component inorganic binder. The starting particles were coated with binary and ternary inorganic binders and mixed with an organic binder to prepare a molded body, and then heat-treated at 1,000/1,350/1,500 °C to prepare a fired body. In the sample where the two-component inorganic binder was applied, the glass was liquefied at a temperature of 1,000 °C or higher, and the strength decreased. However, the firing strength of the ceramic mold sample containing the three-component inorganic binder was improved, and it was confirmed that it was possible to manufacture a ceramic mold and core via high temperature casting.
        4,000원
        942.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        플루옥사스트로빈은 Strobilurus 속의 버섯에서 추출한 천 연물을 기반으로 개발된 살균제로서 곰팡이성 질병 방제에 효과적이다. 잔류물의 정의는 유럽(EU), 미국(EPA), 일본 (JFCRF)에서는 플루옥사스트로빈과 플루옥사스트로빈 Z 이 성질체의 합으로 정의하고 있으며, 감자, 대두 등 90품목 에 대하여 0.01-60 mg/kg으로 잔류허용기준이 설정되어 있 다. 코덱스(CODEX)와 국내에는 잔류허용기준이 설정되어 있지 않음에 따라 본 연구에서는 추후 국내·외 수입 및 재 배 농산물 중 플루옥사스트로빈에 대한 잔류허용기준 준수 여부 확인을 위한 시험법을 개발하고자 하였다. 전처리 과 정은 플루옥사스트로빈의 물리·화학적 특성을 고려하여 QuEChERS법을 이용한 추출 및 정제방법으로 최적화하였 으며, LC-MS/MS를 이용하여 시험법을 개발하였다. 추출 용매는 아세토니트릴로 하고, MgSO4 및 PSA를 이용하여 정제과정을 확립하였다. 대표 농산물 5종에 대해 0.01, 0.1 및 0.5 mg/kg의 처리농도로 실험을 진행한 결과, 플루옥사 스트로빈 및 플루옥사스트로빈 Z 이성질체의 결정계수(R2) 는 0.998 이상이고 플루옥사스트로빈의 평균 회수율(n=5) 은 75.5-100.3%, 플루옥사스트로빈 Z 이성질체는 75.0- 103.9%이었다. 상대표준편차는 플루옥사스트로빈이 5.5% 이하, 플루옥사스트로빈 Z 이성질체가 4.3% 이하로 확인 되었다. 또한 시험법의 유효성을 확인하기 위해 외부 실험 기관인 광주지방식품의약품안전청과의 실험실간 검증을 진 행하였으며, 검증 결과 두 실험실간의 회수율은 플루옥사 스트로빈의 경우 80.3-101.4%, 플루옥사스트로빈 Z 이성질 체는 80.2-105.0%이었고, 상대표준편차는 모두 18.1% 이하 로 정확성 및 재현성이 우수함을 확인할 수 있었다. 따라 서 본 연구 결과는 CODEX 가이드라인(CAC/GL 40-1993, 2003) 및 식품의약품안전평가원의 가이드라인(MFDS, 2016) 에 만족함에 따라 공정시험법으로 활용 가능할 것이다.
        4,300원
        943.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 유아기 부모역량 강화를 위한 비대면 부모코칭프로그램을 개발하 고 유아기 부모에게 실시한 후 프로그램의 효과를 검증하는 데 그 목적이 있다. 이를 위한 절차로 문헌 고찰과 요구도 조사를 통해 프로그램의 기초를 설계하였 고, 전문가 타당도 검토를 통해 수정·보완하여 최종 프로그램을 개발하였다. 부 모역량은 자녀를 양육하고, 부모가 자신의 안녕감과 행복을 위해 자신을 돌보고 관리하며 사회인으로서 사회에 적응하며 다양한 정보를 활용하는 능력을 뜻한 다. 본 프로그램은 10명의 부모와 개별로 온라인플랫폼 상에서 만나 진행되었으 며, 총 10회기, 주 1회, 한 회기당 1시간 30분으로 진행되었다. 사전·사후·추후 검사를 통해 프로그램의 효과를 검증하였다. 본 연구의 결과는 다음과 같다. 첫 째, 유아기 부모역량 강화를 위한 비대면 부모코칭프로그램을 개발하였다. 둘째, 유아기 부모역량 강화 비대면 부모코칭프로그램은 부모의 다중역량을 유의미하 게 증가시켰다. 셋째, 유아기 부모역량 강화 비대면 부모코칭프로그램은 부모의 해결중심 사고를 유의미하게 증가시켰고 유지됨이 확인되었다. 넷째, 유아기 부 모역량 강화 비대면 부모코칭프로그램은 부모의 통찰을 유의미하게 증가시켰으 며, 이후에도 유지됨을 확인하였다. 다섯째, 유아기 부모역량 강화 비대면 부모 코칭프로그램은 양육 스트레스를 감소시켰다
        6,000원
        944.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구의 목적은 발달장애 아동을 위한 태블릿 기반의 인지평가를 통해 세부 인지기능의 프로파일 을 비교함으로써 본 평가가 진단그룹에 따른 인지기능 상태를 평가하는데 변별력이 있는지 알아보고자 하였다. 연구방법 : 총 80명의 만 4~12세 아동이 본 연구에 참여하였다. 진단명별로 자폐 스펙트럼(Autism Spectrum Disorders; ASD) 24명, 지적장애(Intellectual Disability; ID) 20명, 주의력결핍 및 과잉행 동 장애(Attention-Deficit Hyperactivity Disorder; ADHD) 7명, 정상발달 아동 29명이 참여하였다. 태블릿으로 개발된 인지평가는 총 8개 항목으로 공간작업기억, 작업기억용량, 시각적 작업기억, 시지각 처리기술, 집행기능(계획), 집행기능(반응억제 및 주의력), 집행기능(억제)의 세부 인지항목으로 구성되 어 있다. 평가를 시행한 후 진단그룹에 따른 차이를 Kruskal-Wallis 검정을 통해 비교하였다. 통계분석 은 Jamovi 1.6.23 을 사용하였다. 결과 : 정상발달 아동에 비해 자폐 스펙트럼, 지적장애, ADHD 아동의 인지평가 총점이 통계적으로 유의 미하게 다른 것으로 나타났다(χ²= 22.41, p < .001). 정상발달 아동에 비해 자폐 스펙트럼 아동은 시각 처리기술 및 억제기능의 항목에서 유의미한 기능 저하를 보였고, 지적장애 아동은 작업기억 용량, 시각적 작업기억과 반응억제 및 주의력 항목에서 유의미한 기능 저하를 보이는 것으로 나타났다. 한편, ADHD 아동의 경우 정상발달 아동에 비해 통계적으로 유의미한 차이를 보이는 인지평가 항목이 없었다. 결론 : 본 연구에서 개발된 태블릿 기반의 인지평가는 정상발달 아동과 발달장애 아동의 인지기능의 상태 를 변별함으로써 치료의 기초자료로써 활용 가치가 있다.
        4,900원
        946.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2025년이면 대한민국의 노인 인구가 전체인구의 25%를 차지 하는 초고령사회에 도래하게 될 것이다. 해가 갈수록 출산율은 감소하고 노인수명은 늘어나면서 노인 인구의 비중은 증대되는 것이다. 국민 4명 중 한 명이 노인이 되는 세상이다. 따라서 노 인복지, 노인권익, 노인 일자리, 노인자원봉사 등의 문제는 매 우 중요한 자리를 차지하게 될 것이다. 이와 비례하여 노인여 가복지시설인 경로당의 중요성은 더욱 배가될 것이다. 현재 우 리나라의 경로당은 약 68,000개로 노인 인구 900만 명 중 절반 인 400만 명이 활용하는 것으로 조사되었다. 경로효친사상과 홍익인간 정신을 바탕으로 태동한 경로당은 세계에서 유래를 찾아 볼 수 없는 우리 고유의 노인복지시설이다. 경로당은 어 르신들의 여가선용 및 복지의 중심으로 노인들의 생활공간이 다. 서울시 경로당의 경우 다른 시도 노인들에 비해 경로당 이 용 인원도 비교적 많고, 프로그램도 해가 갈수록 전문화되고 다양화되어 가고 있다. 그럼에도 불구하고 아직도 경로당의 복 지 프로그램이나 시설환경 등은 만족한 상태가 아니다. 서울시 경로당을 중심으로 경로당 이용실태 분석을 통한 발전방안을 모색하여 노인복지에 증진에 기여하고자 하였다. 365일 가고 싶은 경로당의 필요충분조건을 찾아내어 그 조건을 충족하게 함으로써 서울시 노인들이 찾고 기다려지는 경로당 활성화에 기여하고자 설문 수렴을 통해 방안을 찾고자 주력하였다. 시대 는 변하고 환경도 변하고 추구하고자 하는 목표나 이상도 시대 상황에 따라 변화되어 간다. 서울시 경로당은 규모가 협소하여 40평 미만인 경로당이 대부분을 차지하고, 회원들은 통상 경로 당을 주 5회 정도 이용하고 있으며, 집에서 경로당까지의 거리 는 300미터 이내로 접근성이 용이한 것으로 나타나고 있다. 서 울시는 앞으로 경로당 활성화를 위하여 다양한 운영방안들을 적극적으로 수용하고, 맞춤형 프로그램 개발을 통해 경로당의 주 기능인 여가, 복지, 교육, 일자리, 자원봉사 등의 기능이 원 활하게 작동되도록 지속적인 관심과 지원이 필요하다고 판단한 다. 현실적인 경로당의 문제들을 심층 깊게 연구하여 전문화, 다양화된 방안으로 개선되어 노인들의 사랑방인 경로당활성화 에 조금이라도 도움이 되었으면 하는 바람이다.
        8,400원
        947.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 코치가 자기효능감을 보다 신뢰롭게 측정하여 자신의 자기효능감 을 객관적으로 인식하도록 돕고, 향후 자기효능감에 기반한 다양한 프로그램 개 발 및 관련 연구를 가능하게 하기 위한 목적으로 코치의 자기효능감 척도를 개 발하였다. 이를 위해 첫 번째, 코치의 자기효능감 척도개발은 1차 예비문항 선정, 2차 척도 개발 과정, 3차 신뢰도와 타당도를 검증하는 과정을 거쳐 진행하였으며, 정 서적 자기효능감, 대인관계 자기효능감, 의사소통 자기효능감의 3가지 구성요 인, 최종 25개 문항이 선별되었다. 두 번째, 코치의 자기효능감 척도의 Cronbach’s α 계수와 모형적합도 지수를 통하여 신뢰도와 타당도를 검증하였다. 본 연구결과로 개발된 3가지 코치의 자기효능감 구성요인은 자기효능감과 코 칭을 이론적 배경으로 하는 중요한 요인으로서, 코치를 위한 다양한 프로그램 개발과 효과성 검증을 위한 자기평가 도구로서 코치의 자기효능감을 증진시키 는데 의의가 있다.
        6,000원
        948.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : A mechanistic-empirical (ME) predictive design logic that can compute the reflective cracking life of hot-mix asphalt (HMA) overlaid on top of a composite pavement is proposed herein. METHODS : The overlay thickness design and analysis logic of the HMA were formulated based on the ME concept of reflection crack propagation. Climate data, traffic load data, the pavement material properties, and the thickness of each layer of the pavement are the main inputs for the ME-Reflective Cracking Rate (RCR) prediction algorithm. An Microsoft Excel Virtual Basic for Application (VBA) program was created to aid designers in assessing the expected performance of an HMA overlay design. Calibration was done using data from the Long-Term Pavement Performance (LTPP) sections. Sensitivity analysis was conducted to compare the results yielded by the program and data from a report by the Texas Transportation Institute. RESULTS : The predictive model performance effectively generates the dynamic and relaxation modulus curves. The correlation value of the calibration factors, R2, is 0.79. The calibration factors used for the Asphalt Overlay Thickness Design (AOTD) program and the sensitivity analysis, i.e., k1, k2,, and k3,, are set to 5, 5, and 150, respectively. The sensitivity of the AOTD program affords reasonable results. Additionally, the program yields results similar to the trends presented in a report by the Federal Highway Administration. CONCLUSIONS : The proposed ME design logic is successfully translated into an Excel VBA program, AOTD, which can perform routine assessments of laboratory tests for HMA overlays. The program can effectively perform numerous iterations and computations to predict an HMA overlay. The predictive model can generate reasonable dynamic modulus and relaxation modulus curves for the characterization of HMA overlays. Under the same asphalt binder grade and HMA type, doubling the HMA overlay thickness yields three times the expected reflective cracking service life.
        4,000원
        949.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Recently, increasing number of local governments are introducing on-demand public transportation service in real time to improve the management efficiency of public transportation. In preparation for the autonomous driving era, the “autonomous public transportation mobility on-demand service in real time” is being developed in the public transportation sector to introduce on-demand public transportation. For this service to become the public transportation of the future, it must receive publicity. Therefore, in this study, indicators were selected to evaluate the publicity of the autonomous public transportation mobility on-demand service in real time, and a survey was conducted among the general public to examine the validity of the indicators. METHODS : To secure the publicity of on-demand public transportation in real time, the goal of the service was first set. Second, the keywords of the service were analyzed to define the publicity requirements of this service. Based on the analyzed keywords and definition of publicity, service indicator types were classified, and the indicators were defined by type. A user satisfaction survey was conducted on the final selected indicators to improve the degree of completion of indicator development. The user survey was conducted by presenting selected publicity indicators to respondents responding on a five-point scale to determine whether each indicator could satisfactorily evaluate publicity. RESULTS : When examining various previous research cases and the contents required for autonomous public transportation mobility on-demand service in real time, the required items of publicity indicators were found to be “safety” in terms of “autonomous driving” and “convenience” in terms of “demand response.” Publicity indicators were developed according to these three items. Thirty-one indicators were developed, and a satisfaction survey was conducted on the general public for each indicator. In the survey, most of the indicators scored 3.5 points or higher, indicating that the indicators were generally well defined. Users gave the highest score to “fairness” among the three items, and “reasonable fairness” was found to be a necessary item as a publicity indicator. CONCLUSIONS : In this study, evaluation indicators were selected to secure the publicity of autonomous public transportation mobility on-demand service in real time, and a satisfaction survey was conducted for each indicator. Most of the indicators showed a score of 3.5 or higher, indicating that they were generally well defined. However, this study has a limitation in that it surveys the general population. In future, experts should be included in the survey to increase the degree of completeness of the public indicators.
        4,000원
        950.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : An automated driving guidance framework was developed for automated vehicles based on cooperation between infrastructure and automated vehicles. The proposed automated driving guidance framework is assumed to function only when an automated vehicle encounters situations in which it cannot safely pass through without cooperation with the infrastructure. METHODS : A four-step concept of automated driving guidance levels was employed, and the decision criteria, such as moving object, event, and externality, were defined as the criteria for determining the automated driving guidance level. The judgment criteria of each stage and procedure for determining the autonomous driving guidance level were determined based on successive judgments, and the proposed automated driving guidance framework was designed based on an expert survey. The survey was aimed at experts with experience related to automated driving system research or technology development. RESULTS : The resulting framework shows the steps and criteria for determining whether automated driving guidance is required under a specific situation and what the guidance should be. CONCLUSIONS : The proposed automated driving guidance framework is designed to function only when an automated vehicle encounters situations in which it cannot safely pass through without cooperation with the infrastructure.
        4,000원
        951.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, an eco-friendly mastic asphalt backfill material is developed to reduce production and construction temperatures by 40 ℃ compared with those recorded when using conventional hot-mix mastic asphalt backfill materials. METHODS : To reduce the production and construction temperatures, SIS polymer modifiers and gum rosin were selected, and gum rosin-modified SIS materials were applied to the mastic asphalt binder mix design. SIS is less viscous than SBS at high temperatures owing to its thermal characteristics, and incorporating gum rosin into SIS causes the latter to exhibit a loose and soft structure. To improve the performance of the mastic asphalt modified with SIS and gum rosin, three different filler mixes, i.e., 100% PMMA, 50% PMMA and 50% calcium carbonate, and 40% PMMA and 60% calcium carbonate were applied. RESULTS : The rosin-modified SIS reduces the viscosity of the developed mastic asphalt binders. In particular, incorporating 3.7% of gum rosin is beneficial to the mastic binder and does not degrade its low-temperature performance. Similarly, using 100% PMMA as a filler improves the performance but results in workability issues at high temperatures. CONCLUSIONS : Rosin-modified SIS and PMMA are promising alternatives for increasing the workability at high temperatures while maintaining the target performance of grade PG82-22 binders if the appropriate ratio of calcium carbonate is mixed with PMMA and an alternative filler comprising calcium carbonate is used.
        4,000원
        952.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, high-viscosity grout for increasing ground stiffness is developed using industrial byproducts. METHODS : Based on literature review, the viscosity and viscosity expression time of domestic and foreign anti-washout admixture underwater were evaluated. In addition, grout was prepared by mixing 5% to 40% of fly ash (FA) in a standard mixture. Flow, setting time, and compressive strength tests were conducted to evaluate the quality of the grout. RESULTS : Experimental results show that the viscosity required is 35,000 to 40,000 cps, whereas the viscosity expression time required exceeds 300 min. As the amount of FA used for grouting increases, the physical and mechanical performances deteriorate. The strength of a test specimen manufactured underwater is lower than that of a test specimen manufactured under air, and the decrease on day 28 is lower than that on day 3. The FA applied to the grout should be less than 20%. CONCLUSIONS : Although industrial byproducts, which exhibit high viscosity, offer excellent mechanical performance and are thus suitable as a solidifying agent for strengthening grout, their application in the field must be evaluated.
        4,000원
        953.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, a system is investigated and developed to remove fog by injecting air onto a road using high-pressure air generated by turbo blowers installed on both edges of the road without using artificial chemicals. METHODS : A test device was constructed on a scaled road measuring 5 m long. A 225 kW class turbo blower was used to supply air. An air injection nozzle was installed to allow high-pressure air supplied from the turbo blower to be sprayed vertically from the edge of the road and horizontally from the surface of the road. Ten micro humidifiers were used to generate fog. RESULTS : Experimental results show that when ground fog occurs on the road, spraying air only in the vertical direction cannot effectively remove the fog. However, when vertical and horizontal nozzles are used simultaneously, both ground fog and flowing fog are removed effectively. CONCLUSIONS : A system for removing fog by spraying air jet is constructed, and fog is generated using a micro humidifier. Results from the fog removal performance test show that the system effectively removes fog.
        4,000원
        954.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, we propose a mini-trench method, which involves using warm mix Guss mastic asphalt as a backfill material and an installation temperature of 160 ℃. The method is verified via a heat transfer analysis of a pavement using the finite element method. METHODS : First, the density, thermal conductivity, and specific heat required for heat transfer analysis were determined based on previous studies. Subsequently, the boundary conditions for convection and radiation to perform the heat transfer analysis were determined. The pavement temperature, which is the initial condition of the analysis, was determined based on the summer pavement temperature distribution using the temperature prediction program of the Korean pavement Research Program. Heat transfer analysis was performed by determining the temperature of the backfill material based on 160 °C and 200 °C for the heat load temperatures. The temperature change was observed on the backfill surface, and the temperature change of the conduit was observed directly. RESULTS : When the pavement surface temperature for traffic opening is 50 °C, the backfill thickness ranges from 50 to 250 mm, the warm mix Guss mastic asphalt requires 2 h to 5 h, 15 min until traffic opening, and the hot mix Guss mastic asphalt requires 2 h, 30 min to 6 h, 40 min until traffic opening. The limit temperature of the conduit evaluated based on KS C 8454 shows that the warm mix Guss mastic asphalt does not satisfy the standard when the backfill concrete cover is 50 mm thick, whereas the hot mix Guss mastic asphalt does not satisfy the standard when the concrete cover is 50 and 100 mm thick. CONCLUSIONS : The backfill depth of the mini-trench using warm mix Guss mastic asphalt as a backfill material should be less than 100 mm, considering the traffic opening time. Meanwhile, the thickness of the backfill concrete should be 100 mm or less.
        4,000원
        955.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Fine dust significantly affects the atmospheric environment, and various measures have been implement to reduce it. The aim of this study is to reduce fine dust on roads by implementing porous pavements and a clean road system using the low-impact development technique. METHODS : We conducted quality tests (draindown, cantabro loss rate, tensile strength ratio, dynamic stability, and indoor permeability coefficient tests) and performance evaluation (dynamic modulus and Hamburg wheel-tracking tests) on the porous asphalt mixture. Subsequently, we constructed a porous pavement road in a test bed and conducted a permeability test. In the test bed, we installed a nozzle, a water tank, and a fluid pump to water the roadside. After the clean road system was completely installed, we measured the concentration of fine dust before and after water was sprayed. Additionally, we conducted a total suspended solids (TSS) test to confirm the reduction in re-suspended dust. RESULTS : All results from the quality test of the porous asphalt mixture satisfy the standards stipulated by the Ministry of Land, Infrastructure and Transport. Results from the dynamic modulus test show a low plastic deformation resistance but a high fatigue crack resistance. The results from the Hamburg wheel-tracking test satisfy the U.S. Department of Transportation standards. After the porous pavement was constructed, a permeability test was conducted, and the result satisfies the standard value. Using a particle counter, we measured the concentration of fine dust before and after water spraying, and results show 12.08% and 10.23% for PM10 and PM2.5 particles, respectively. The results from the TSS test show that after the initial water spray, almost all re-suspended dust are removed from a road. In unfavorable road conditions, almost all re-suspended dust are removed after a second water spray. CONCLUSIONS : The results of all of quality tests performed on a porous asphalt mixture satisfy the standards. By applying the results to a test bed, the problem of securing water is solved. Using the clean road system, 12.08% and 10.23% of PM10 and PM2.5 particles are removed, respectively. The system removes PM10 particles (larger particles) more effectively compared with PM2.5 particles. IN the future, we plan to revise the maintenance plan such that the porous pavement can exhibit long-term performance. Because pipe freezing may occur in the winter, we plan to analyze the periodic maintenance plan of the porous pavement and develop a solution to mitigate the issue of freezing pipes in the winter.
        4,300원
        956.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The paper introduces an experimental program for the newly developed vertical joints between Precast Concrete (PC) walls to improve their in-plane shear capacity. Compared to the existing vertical joints, two types of vertical joints were developed by increasing the transverse reinforcement ratio and improving frictional force at the joint interface. A total of four specimens including the Reinforced Concrete (RC) wall and PC walls with developed vertical joints were designed and constructed. The constructed specimens were experimentally investigated through monotonic shear tests. The observed damage, load-deformation relationship, strain and strength are investigated and compared with the cases of RC wall specimen. Experimental results indicate that the maximum force and initial stiffness of the PC wall with proposed vertical joints were decreased by comparing with those of RC wall. However, the ultimate displacement increased by up to 217.30% compared to the RC wall specimen. In addition, brittle failure did not occurred and relatively few cracks and damages occurred.
        4,000원
        957.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, surface distress (SD), rutting depth (RD), and international roughness index (IRI) prediction models are developed based on the zones of Incheon and road classes using regression analysis. Regression analysis is conducted based on a correlation analysis between the pavement performance and influencing factors. METHODS : First, Incheon was categorized by zone such as industrial, port, and residential areas, and the roads were categorized into major and sub-major roads. A weather station triangle network for Incheon was developed using the Delaunay triangulation based on the position of the weather station to match the road sections in Incheon and environmental factors. The influencing factors of the road sections were matched Based on the developed triangular network. Meanwhile, based on the matched influencing factors, a model of the current performance of the road pavement in Incheon was developed by performing multiple regression analysis. Sensitivity analysis was conducted using the developed model to determine the influencing factor that affected each performance factor the most significantly. RESULTS : For the SD model, frost days, daily temperature range, rainy days, tropical nights, and minimum temperatures are used as independent variables. Meanwhile, the truck ratio, freeze–thaw days, precipitation days, annual temperature range, and average temperatures are used for the RD model. For the IRI model, the maximum temperature, freeze–thaw days, average temperature, annual precipitation, and wet days are used. Results from the sensitivity analysis show that frost days for the SD model, precipitation days and freeze–thaw days for the RD model, and wet days for the IRI model impose the most significant effects. CONCLUSIONS : We developed a road pavement performance prediction model using multiple regression analysis based on zones in Incheon and road classes. The developed model allows the influencing factors and circumstances to be predicted, thus facilitating road management.
        4,300원
        958.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : To efficiently manage pavements, a systematic pavement management system must be established based on regional characteristics. Suppose that the future conditions of a pavement section can be predicted based on data obtained at present. In this case, a more reasonable road maintenance strategy should be established. Hence, a prediction model of the annual surface distress (SD) change for national highway pavements in Gangwon-do, Korea is developed based on influencing factors. METHODS : To develop the model, pavement performance data and influencing factors were obtained. Exploratory data analysis was performed to analyze the data acquired, and the results show that the data were preprocessed. The variables used for model development were selected via correlation analysis, where variables such as surface distress, international roughness index, daily temperature range, and heat wave days were used. Best subset regression was performed, where the candidate model was selected from all possible subsets based on certain criteria. The final model was selected based on an algorithm developed for rational model selection. The sensitivity of the annual SD change was analyzed based on the variables of the final model. RESULTS : The result of the sensitivity analysis shows that the annual SD change is affected by the variables in the following order: surface distress ˃ heat wave days ˃ daily temperature range ˃ international roughness index. CONCLUSIONS : An annual SD change prediction model is developed by considering the present performance, traffic volume, and climatic conditions. The model can facilitate the establishment of a reasonable road maintenance strategy. The prediction accuracy can be improved by obtaining additional data, such as the construction quality, material properties, and pavement thickness.
        4,300원
        959.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        콩줄기명나방은 콩과작물 특히 팥을 가해하는 해충으로 알려져 있다. 본 연구는 온도가 콩줄기명나방의 발육단계별 발육기간, 성충의 수명 과 산란특성에 미치는 영향을 파악하고자 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 36°C 항온조건에서 조사하였다. 알과 유충은 7, 10, 13°C를 제 외한 항온조건에서 다음 생애단계로 성공적으로 발육하였다. 알, 유충, 번데기의 발육기간은 온도가 상승할수록 짧아지는 경향을 보였다. 콩줄기 명나방 발육단계별 발육 최저, 최고 한계는 LRF와 SSI모델을 이용하여 계산하였고 발육영점온도와 유효적산온일도는 선형회귀분석을 이용하 였다. 1령 유충 부화부터 성충출현까지의 발육영점온도와 유효적산온일도는 13.5°C와 384.5DD로 추정되었다. SSI모델을 이용한 부화부터 성 충출현까지 발육 최저 및 최고온도는 19.4°C과 39.8°C였고 이들간의 차이 즉 발육적정온도범위는 20.4°C였다. 성충은 16°C와 34°C 범위에서 부화하는 알을 생산하였고, 25°C에서 최대 약 416마리의 자손을 낳았다. 노화율, 나이별 생존율, 나이별 누적산란율, 온도의존 산란수에 관련된 성충모델들이 작성되었다. 본 연구에서 제시한 온도발육모형과 산란모형은 야외에서 콩줄기명나방의 개체군동태를 이해하고 콩과작물의 종합적 인 해충군관리체계를 마련하는데 기초기반자료로 활용될 것으로 기대된다.
        4,600원
        960.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        콩명나방은 콩과작물 특히 팥을 가해하는 해충으로 알려져 있다. 본 연구는 콩명나방의 생물적 특징을 알아보기 위해 발육단계별 발육기 간, 성충의 수명과 번식능력을 13, 16, 19, 22, 25, 28, 31, 34°C 항온조건에서 조사하였다. 알은 모든 항온조건에서 부화하였고 유충은 16~ 31°C 온도조건에서 성공적으로 성충까지 발육을 완료하였다. 알의 발육기간은 31°C까지 온도가 상승할수록 짧아지다가 이후 온도에서 길어지 는 경향을 보였다. 유충, 번데기의 발육기간과 성충수명은 온도가 상승할수록 감소하였다. 콩명나방 발육단계별 발육 최저, 최고 한계는 LRF와 SSI모델을 이용하여 계산하였고 발육영점온도와 유효적산온일도는 선형회귀분석을 이용하였다. 1령 유충 부화부터 성충출현까지의 발육영점온 도와 유효적산온일도는 12.8°C와 280.8DD였다. SSI모델을 이용하여 추정한 부화부터 성충출현까지 발육최저 및 최고온도는 14.2°C과 31.9°C였고 이들간의 차이 즉 발육적정온도범위는 17.7°C였다. 온도와 관련된 콩명나방 성충의 생존, 수명, 산란기간, 산란수 자료들을 이용하 여 산란모형을 작성하였다. 본 연구에서 제시한 온도발육모형과 산란모형은 야외에서 콩명나방의 개체군동태를 이해하고 콩과작물의 종합적인 해충군관리체계 확립에 기여할 것으로 보인다.
        4,500원