PURPOSES : Snow-removal performance is performed in this study to assess the feasibility of replacing calcium-chloride solution with sodium chloride solution at the minimum temperature of -5 ℃ during snowfall. METHODS : The atmospheric temperature distribution in Seoul was analyzed. The manufacturing, storage, and indoor melting performance of calcium-chloride and sodium-chloride solutions were evaluated, and on-site snow-removal performance was evaluated based on the solution type. RESULTS : According to the results of the melting performance test at -5°C, the melting capacity of the sodium chloride solution was expressed at a level exceeding 90% of that of the calcium chloride solution, indicating a similar melting performance between the two solutions. Additionally, based on the snow removal performance test using aqueous solutions, the snow removal performance of the sodium chloride solution was found to be approximately 96% compared to that of the calcium chloride solution, indicating minimal differences in snow removal performance due to changes in the type of solution. CONCLUSIONS : Similar snow-removal performance was achieved when the sodium chloride solution was used instead of calciumchloride aqueous solution at temperatures exceeding -5 ℃.

서필리핀분지는 필리핀해판 서쪽 그리고 유라시아판에 위치한 한반도의 남쪽에 위치하여 류큐해구를 경계로 두 고 있는 해양 분지이다. 이 분지는 전체 필리핀 판의 절반정도의 크기이며 류큐해구, 필리핀해구를 경계로 유라시아판 하부로 섭입 중이다. 이 분지의 25-50%가 이미 섭입되었고, 분지 남쪽의 경우 연구가 거의 이루어지지 않아 현재까지 분지의 진화과정 해석에 대하여 크게 논란 중에 있다. 이러한 논란을 해소하기 위해 서필리핀분지의 진화과정을 고해상 도 다중빔음향측심자료 분석을 통해 확인하였다. 판의 확장과정에서 생성되는 비변환불연속 구조(Non-Transform Discontinuity)는 일반적으로 중앙해령과 수직한 방향으로 생성되는 변환단층 경계와 유사하지만 지각아래 맨틀대류 변 화에 의한 마그마공급 불균형으로 해령분절에 변위가 생기며 만들어진다. 고해상도 해저지형도를 제작하여 분석한 결과, 해령전파에 의한 비변환불연속 구조가 크게 발달한 것과 전반적인 심해언덕의 주향이 해령에서 멀어질수록 E-W방향에 서 NNW-SSE방향으로 변화하는 것을 확인하였다. 분지 확장 초기에 아마미-산카쿠 분지가 현재의 위치에서 90도 시계 방향으로 회전된 상태로 팔라우분지와 인접해 있다가 분지의 확장이 시작되면서 민다나오 파쇄대를 경계로 팔라우분지 와 분리되어 반시계 방향의 회전열개로 확장을 한 것으로 여겨진다. 또한 분지 내 비변환불연속 구조는 ENE-WSW 방 향에서 N-S 방향으로 급격한 확장방향의 변화와 동시에 필리핀해판의 드리프트(drift)로 인한 갑작스러운 마그마 공급 변화로 형성될 수 있음을 지시한다. 팔라우분지는 WPB의 남쪽 일부로 간주되었으나, 최근의 연구에 따르면 독립적인 시스템으로 확장한 것으로 밝혀졌다. 퇴적층과 지각의 두께 등 여러 단서들이 팔라우분지가 WPB 확장 이전에 이미 존 재했을 가능성을 시사하고 있으나 분지의 진화과정은 여전히 논란이 많다. 서필리핀분지와 필리핀해판의 정확한 진화과 정을 이해하기 위해서 팔라우 분지의 연대와 확장 진화에 대한 연구가 필요하다. 본 연구는 고해상도 다중빔음향측심자 료 분석을 통해 서필리핀분지의 진화과정에 대한 새로운 정보를 제공하였다. 이러한 정보는 서필리핀분지와 필리핀해판 의 정확한 진화과정을 이해하는 데 중요한 역할을 할 것으로 기대된다.

In this study, the performances of H2S, NH3, and HCl sensors for real-time monitoring in small emission facilities (4, 5 grades in Korea) were evaluated at high concentration conditions of those gases. And the proper approach for the collection of reliable measurement data by sensors was suggested through finding out the effect on sensor performances according to changes in temperature and humidity (relative humidity, RH) settings. In addition, an assessment on sensor data correction considering the effects produced by environmental settings was conducted. The effects were tested in four different conditions of temperature and humidity. The sensor performances (reproducibility, precision, lower detection limit (LDL), and linearity) were good for all three sensors. The intercept (ADC0) values for all three sensors were good for the changes of temperature and humidity conditions. The variation in the slope value of the NH3 sensor showed the highest value, and this was followed by the HCl, H2S sensors. The results of this study can be helpful for data collection by enabling the more reliable and precise measurements of concentrations measured by sensors.

PURPOSES : The number of snowfall and the amount of snowfall are gradually increasing, and due to the characteristics of Seoul, which has a lot of traffic, it is difficult to respond quickly with a snow removal method that relies on snow removal vehicles. Therefore, it is necessary to develop an IoT based eco-friendly snow removal system that can respond to unexpected heavy snow in winter. In this study, the low temperature operation and snow removal performance of the IoT road condition snow removal detector and the snow removal system using CNT and PCM are evaluated in the climatic environment chamber. METHODS : To make artificial snow, it consists of an climatic environment chamber that can simulate a low temperature environment and equipment that can supply compressed air and cold water. Depending on the usage characteristics of the climatic environment chamber, use an air-water type snow maker. In order to make artificial snow, wet temperature, which takes into account the actual air temperature and the amount of moisture in the air, acts as the most important variable and is suitable for making snow, below –1.5 ℃. The lower the water temperature, the easier it is to freeze, so the water source was continuously supplied at 0 ℃ to 4 ℃. One of the two different pipes is connected to the water tank to supply water, and the other pipe is connected to the compressor to supply high-pressure air. Water is dispersed by compressed air in the form of many small droplets. The sprayed microscopic water particles freeze quickly in the low temperature environmental climatic chamber air and naturally fall to the floor, forming snow. Based on the KS C IEC 60068-2-1 cold resistance test standard, an integrated environmental test procedure was prepared to apply to IoT-based snow removal systems and performance evaluation was performed accordingly. The IoT based eco-friendly snow removal system is needed to in winter, so visual check and inspect the operation at the climatic chamber before setting up it to the actual site. In addition, grid type equipment was manufactured for consistent and reliable snow removal performance evaluation under controlled environmental conditions. RESULTS : The IoT-based eco-friendly snow removal system normally carried out the task of acquiring data and images without damaging the appearance or freezing in a low temperature environment. It showed clear snow removal performance in areas where PCM and CNT heating technology were applied to the concrete slab. This experiment shows that normal snow removal tasks can be carried out in low temperature environments in winter. CONCLUSIONS : The integrated environmental test procedures and grid type evaluation equipment are applied to low temperature operation and snow removal performance evaluation of snow removal systems. In the climatic environment chamber, where low temperature environments can be simulated, artificial snow is created regardless of the season to derive quantitative experimental results on snow removal performance. PCM and CNT heating technology showed high snow removal performance. The system is expected to be applied to road site situations to preemptively respond to unexpected heavy snow in winter.

EU와 OECD는 EU 회원국 성인이 금융 생활을 하고 정보에 기초한 의사결정을 하는 데 필요한 핵심 금융 역량을 개발했다. 기본적으로는 OECD가 앞서 개발한 청소년, 중소기업 인, 성인 등을 위한 금융 역량 틀과 동일한 것으로 평가할 수 있지만, 디지털 금융 환경의 확산과 금융의 지속 가능성에 관한 관심 증가 같은 최근의 변화를 최대한 반영해 핵심 금융 역량에도 관련 성취 기준을 대폭 보강했다는 의의가 있다. 이 연구에서는 EU 회원국의 성인 을 대상으로 한 구체적인 핵심 역량과 564개에 이르는 성취 기준을 번역해 소개한다.

The air dilution olfactory method to measure complex odors needs to store and carry odor samples from the field sampling until the analysis in laboratories. Until the analysis of sample in the laboratory, odor dilution factor (odor sensitivity) in the sample bag may decrease over time depending on the characteristics of each odor substances. This is one of the limitation for the air dilution olfactory method. Thus, the air dilution device enable to measure without loss in complex odors of samples. Recently, many studies on the performance test of on-site air dilution devices, i.e., field olfactometer, has been conducted to figure out the feasibility of the field olfactometers. In this study, seven odor samples were collected from five odor emission source sites. And comparative analysis with the air dilution olfactory method was carried out to assess the field applicability of the olfactometer. As results, the performance of the field olfactometer used in this study is regared as the affordable method. The dilution factors from between two methods showed the similar values, indicating low values of standard deviations. In order to ensure the accuracy and precision of measurement data using the field olfactometer, methodology minimized variables (that may affect measurement) needs to establish.

In this paper, a dynamic centrifuge model test was conducted on a 24.8-meter-deep excavation consisting of a 20 m sand layer and 4.8 m bedrock, classified as S3 by Korean seismic design code KDS 17 10 00. A braced excavation wall supports the hole. From the results, the mechanism of seismically induced earth pressure was investigated, and their distribution and loading points were analyzed. During earthquake loadings, active seismic earth pressure decreases from the at-rest earth pressure since the backfill laterally expands at the movement of the wall toward the active direction. Yet, the passive seismic earth pressure increases from the at-rest earth pressure since the backfill pushes to the wall and laterally compresses at it, moving toward a passive direction and returning to the initial position. The seismic earth pressure distribution shows a half-diamond distribution in the dense sand and a uniform distribution in loose sand. The loading point of dynamic thrust corresponding with seismic earth pressure is at the center of the soil backfill. The dynamic thrust increased differently depending on the backfill's relative density and input motion type. Still, in general, the dynamic thrust increased rapidly when the maximum horizontal displacement of the wall exceeded 0.05 H%.

We used the measurement data derived from a proton transfer reaction time-offlight mass spectrometry (PTR-ToF-MS) to ascertain the source profile of volatile organic compounds (VOCs) from 4 major industrial classifications which showed the highest emissions from a total of 26 industrial classifications of A industrial complex. Methanol (MOH) was indicated as the highest VOC in the industrial classification of fabricated metal manufacture, and it was followed by dichloromethane (DM), ethanol (EN) and acetaldehyde (AAE). In the industrial classification of printing and recording media, the emission of ethylacetate (EA) and toluene (TOL) were the highest, and were followed by acetone (ACT), ethanol (EN) and acetic acid (AA). TOL, MOH, 2-butanol (MEK) and AAE were measured at high concentrations in the classification of rubber and plastic manufacture. In the classification of sewage, wastewater and manure treatment, TOL was the highest, and it was followed by MOH, H2S, and ethylbenzene (EBZ). In future studies, the source profiles for various industrial classifications which can provide scientific evidence must be completed, and then specified mitigation plans of VOCs for each industrial classification should be established.

금융 지식은 금융 역량을 구성하는 핵심 요소 가운데 하나로서, 금융교육의 궁극 목표인 금융 웰빙 달성에 긍정적으로 기여한다. 실제로 개인의 금융 지식은 그 사람의 다양한 금융 행위와 금융 태도에 영향을 미친다. 본 연구에서는 일상생활의 돈 관리에서의 위험 감수도 와 금융 지식 사이의 관계를 탐색하기 위해서 800명의 성인을 대상으로 수집한 자료를 분 석한다. 우리나라 성인의 금융 지식은 100점 만점에 평균 57.14점이며, 남자가 여자보다 평균 6.5점 높다. 학력, 직업, 투자 경험, 주택 소유, 경제기사 읽기, 소득이나 재산 상태에 따라 금융 지식 수준도 유의하게 다르다. 응답자들은 대체로 주가의 변동성이 크며 인플레 이션으로 인해 예금의 구매력이 하락한다는 사실을 알고 있는 반면에, 채권과 관련한 지식 이 미흡하다. 그리고 최대 수익을 위해 위험을 기꺼이 감수하기보다는 적당한 수익을 보장 하는 안전한 투자를 선호하는 경향이 있다. 추정 결과에 따르면 금융 지식과 위험 감수도 사이에 유의한 관계가 있어, 금융 지식 수준이 높은 사람일수록 높은 수익률을 위해 손실 위험을 기꺼이 감수하려는 성향이 있음을 확인할 수 있다. 객관식 문항으로 측정한 실제 금융 지식보다는 본인이 스스로 평가한 인지 금융 지식이 위험 감수도와 더 밀접한 관계를 지닌다. 여자보다는 남자의 위험 감수도가 높다. 마지막으로 금융 지식 수준이 높은 사람이 중요한 금융 의사결정을 할 때 가족이나 전문가로부터 조언을 구하는 경향이 있다.

금융교육의 목표와 방향을 개인의 금융 역량 강화에 두고 이를 위한 실천 전략을 마련하려 면, 먼저 개인의 금융 역량 수준을 파악하고 개선이 필요한 역량의 하위 영역이 무엇인지를 구체적으로 파악하고 있어야 한다. 금융 역량을 지식, 태도, 행위의 3개 하위 영역으로, 내 용별로는 기초, 소득과 소비, 예금과 투자, 부채와 신용, 보험과 연금의 5개 하위 영역으로 구분한 후 각 영역에 같은 비중을 두고 성인의 금융 역량을 측정했다. 금융 지식의 평균 점수는 15개 만점 기준으로 9.38개이며, 남자가 여자보다 높다. 나이가 많아질수록 금융 지식 수준이 높아져 50대부터는 평균이 10개를 넘어선다. 학력과 소득 수준이 높고 투자를 활발히 하는 사람의 금융 지식 수준이 높다. 복리, 물가와 생계비의 관계, 예금자 보호 제도 의 구체적 내용, 보험 관련 핵심 용어에 대한 이해도가 매우 낮다. 금융 태도와 금융 행위 모두 예금과 투자 영역에서 개선의 여지가 가장 많으며, 특히 높은 수익률을 추구하면서도 위험은 감수하려 하지 않으며, 금융 의사결정에 대한 자신감이 부족한 것으로 나타났다. 개 인연금에 가입하지 않은 성인도 많이 있어 노후대비가 취약하다는 문제도 드러났다. 이와 같은 조사 결과를 고려하면, 금융교육의 우선순위를 복리의 의미, 구체적인 예금자 보호 제 도 내용, 대출 상환 기간과 부담 이자 사이의 관계, 대출 시 복리의 적용, 수익성과 안전성 사이의 상충 관계, 예금이나 투자 관련 역량, 개인연금에 대한 접근 등에 둘 필요가 있다.

본 논문에서는 전이보 시스템이 지닌 층고 및 공사물량 증가의 단점을 보완할 수 있는 경계보-벽체 시스템의 압축성능을 평가하였 다. 1/2 축소실험체에 대한 압축실험을 수행하고 그 결과를 3차원 비선형 유한요소해석 결과와 비교 및 분석하였다. 실험체 변수로 상 하부벽체의 수평길이 상대비, 하부벽체의 두께, 하부벽체 전단보강근의 상세를 고려하였다. 실험의 최대하중은 하부벽체의 공칭축강 도와 유사하게 나타났으며, 이로부터 상부벽체로부터의 수직 하중이 하부벽체로 원활하게 전달되며, 편심으로 인한 모멘트 중 상당 량을 경계보가 가져감을 알 수 있다. 상하부벽체 수평길이의 상대비가 40%일 경우 50%일 때보다 단면의 기여도가 증가하였으며, 하 부벽체에 면외방향 편심이 존재할 경우 단면의 기여도가 감소하였다. 하부벽체의 전단보강근 간격을 줄이고 크로스 타이를 배근할 경우 초기강성 및 최대하중이 증가하며 국부적인 응력집중이 감소하였다.

PURPOSES : Road surface conditions are vital to traffic safety, management, and operation. To ensure traffic operation and safety during periods of snow and ice during the winter, each local government allocates considerable resources for monitoring that rely on field-oriented manual work. Therefore, a smart monitoring and management system for autonomous snow removal that can rapidly respond to unexpected abrupt heavy snow and black ice in winter must be developed. This study addresses a smart technology for automatically monitoring and detecting road surface conditions in an experimental environment using convolutional neural networks based on a CCTV camera and infrared (IR) sensor data. METHODS : The proposed approach comprises three steps: obtaining CCTV videos and IR sensor data, processing the dataset acquired to apply deep learning based on convolutional neural networks, and training the learning model and validating it. The first step involves a large dataset comprising 12,626 images extracted from the acquired CCTV videos and the synchronized surface temperature data from the IR sensor. In the second step, image frames are extracted from the videos, and only foreground target images are extracted during preprocessing. Hence, only the area (each image measuring 500 × 500) of the asphalt road surface corresponding to the road surface is applied to construct an ideal dataset. In addition, the IR thermometer sensor data stored in the logger are used to calculate the road surface temperatures corresponding to the image acquisition time. The images are classified into three categories, i.e., normal, snow, and black-ice, to construct a training dataset. Under normal conditions, the images include dry and wet road conditions. In the final step, the learning process is conducted using the acquired dataset for deep learning and verification. The dataset contains 10,100 (80%) data points for deep learning and 2,526 (20%) points for verification. RESULTS : To evaluate the proposed approach, the loss, accuracy, and confusion matrix of the addressed model are calculated. The model loss refers to the loss caused by the estimated error of the model, where 0.0479 and 0.0401 are indicated in the learning and verification stages, respectively. Meanwhile, the accuracies are 97.82% and 98.00%, respectively. Based on various tests that involve adjusting the learning parameters, an optimized model is derived by generalizing the characteristics of the input image, and errors such as overfitting are resolved. This experiment shows that this approach can be used for snow and black-ice detections on roads. CONCLUSIONS : The approach introduced herein is feasible in road environments, such as actual tunnel entrances. It does not necessitate expensive imported equipment, as general CCTV cameras can be applied to general roads, and low-cost IR temperature sensors can be used to provide efficiency and high accuracy in road sections such as national roads and highways. It is envisaged that the developed system will be applied to in situ conditions on roads.

PURPOSES : In this study, a method for evaluating concrete bridge deck deterioration using three-dimensional (3D) ground penetrating radar (GPR) survey data and its in situ application are discussed. METHODS : Field surveys are conducted on two bridges in Yongsan-gu (Bridge A) and Seodaemun-gu (Bridge B) in Seoul using 3D GPR. The obtained survey data are used to calculate the dielectric constant map of each bridge using the extended common midpoint method. In addition, random points on both bridges are selected for the chloride content test in accordance with the KS F 2713 standard. The results from the dielectric constant map and chloride content test are compared. RESULTS : For Bridge A, it is discovered that the percentage of sections with a dielectric constant of 5.0 or less is 1.57%, whereas that above 5.0 is 98.43%; this indicates that the percentage of deteriorated sections for Bridge A is low. Meanwhile, for Bridge B, the dielectric constants calculated for the entire bridge exceed 5.0, which suggests no deterioration for Bridge B. Moreover, all the points selected for the chloride content test have less than 0.15% chloride content and have dielectric constants ranging from 5.0 to 7.0, which are favorable condition for the bridge deck. CONCLUSIONS : The analysis results of the dielectric constants of the concrete bridge deck obtained from the 3D GPR system are consistent with the actual chloride content results. Furthermore, additional verification of this method through field surveys on bridge sections with severe deterioration is highly recommended for future improvements.