Particulate matter is known to have adverse effects on health, making it crucial to accurately gauge its concentration levels. While the recent advent of low-cost air sensors has enabled real-time measurement of particulate matter, discrepancies in concentrations can arise depending on the sensor used, the measuring environment, and the manufacturer. In light of this, we aimed to propose a method to calibrate measurements between low-cost air sensor devices. In our study, we introduced decision tree techniques, commonly used in machine learning for classification and regression problems, to categorize particulate matter concentration intervals. For each interval, both univariate and multivariate multiple linear regression analyses were conducted to derive calibration equations. The concentrations of PM10 and PM2.5 measured indoors and outdoors with two types of LCS equipment and the GRIMM 11-A device were compared and analyzed, confirming the necessity for distinguishing between indoor and outdoor spaces and categorizing concentration intervals. Furthermore, the decision tree calibration method showed greater accuracy than traditional methods. On the other hand, during univariate regression analysis, the proportion exceeding a PM2.5/PM10 ratio of 1 was significantly high. However, using multivariate regression analysis, the exceedance rate decreased to 79.1% for IAQ-C7 and 89.3% for PMM-130, demonstrating that calibration through multivariate regression analysis considering both PM10 and PM2.5 is more effective. The results of this study are expected to contribute to the accurate calibration of particulate matter measurements and have showcased the potential for scientifically and rationally calibrating data using machine learning.

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.

PURPOSES : The objective of this study is to present a practical application method for measuring the setting time of concrete in the field, considering different concrete blending and curing environments. METHODS : In the experimental environment of the concrete setting experiment, a mold was made in the laboratory, and the curing temperature was performed at laboratory room temperature (20-25 ℃), heater (30 ℃), and dryer (40 ℃). In the field, the experimental method was performed in summer and autumn, setting experiments on penetration resistance, ultrasonic pulse velocity, and semi-calorimeter. RESULTS : The result of the concrete setting time experiment was that the early setting time was achieved in the combination of filash and slag when the concrete was mixed, and the setting time in the curing environment was the same as the early setting time in the field. The setting time measurement method shows the correlation of the high crystal coefficient at UPV with 0.99 based on PR and the good ratio of 92 % to 107 % on average. In addition, the semi-calorimeter shows a good crystal coefficient of 0.96 to 0.99 and a good setting time of 88 % to 101 % on average. CONCLUSIONS : The analysis of the setting time of the concrete shows that the curing temperature is more affected than the mixture, and it is considered that the UPV test, which evaluates the reliability of the degree of purification, is easy to sampie among the three methods.

With the advancement of industrialization, modern industry had sophisticated technology, and manufacturers also demanded high-precision measurement accuracy. Improving the quality level by increasing the reliability of measurement results as well as accurate measurement is a key issue to increase the competitiveness of today's manufacturing industry. In general, measurement results depend on tolerances in the industrial field, and it may be difficult to guarantee the reliability of the data in the case of an industry that deals with precision parts. Currently, measurement uncertainty is mainly applied to the calibration and test fields of instruments. This study is aim to apply measurement uncertainty as a way to improve the accurate analysis and reliability of measurement results in the industrial field. For this, precision parts connected by shaft and hole were selected among geometric elements, and roundness and cylindricity were measured using a roundness measuring instrument and CMM. And, taking into account the environment in which these measurements were made, factors affecting the measurement results were derived, and a mathematical model was established to calculate the measurement uncertainty. Applying uncertainty in the field in this way is expected to improve the level of quality and accurate analysis of measurement results.

This study investigated the odor dilution rate at 15 locations around three schools in Seoul using an onsite olfactometer. In addition, odor intensity, odor quality, and hedonic tone by direct sensory method were measured along with measurement of the field odor dilution rate, and instrument analysis using odor sensor array and TD-GC was also measured. Onsite olfactometer measurements show that only one of the three schools measured odors exceeding the strict emission acceptance standard of 10 at three points. The average odor intensity at each point measured by the direct sensory method of five persons was in the range of 2.7 to 0.3. The difference in the number of odor dilution rates around schools in Seoul could be related to the level of income by region. The odor environment around each school was judged to be well managed in areas with higher income levels, indicating a lower odor dilution rate. The correlation coeffcient between the odor intensity measured by the direct sensory method and the onsite olfactometer was 0.79, indicating high correlation. The correlation coefficient of sensor array and TD-GC toward the odor intensity was -0.28 and 0.02, respectively. This suggests that a method based on a person's sense of smell should be introduced when measuring low-level odor dilution rates in non-industrial areas, such as school zones.

PURPOSES : This study primarily aims to develop and evaluate a Smart Station - a novel underground pipeline measure system - to overcome the challenges of conventional surveying methods. METHODS : This study built two prototypes of the Smart Station. By reflecting issues revealed through the field tests of the first prototype, this study produced the second Smart Station prototype. The organization of the hardware units in the second prototype was reconfigured to maximize its usability for operators in the field. Furthermore, by developing the ‘Digital Twin X’, an integrated Smart Station management software suite, the second prototype was capable of 1) producing a digital workbook for field operators, 2) managing underground pipeline information, and 3) displaying 3-dimensional maps in and around an underground pipeline. The applicability of the second prototype was examined through three field tests conducted in one open space location, where no urban valley effects were expected, and two locations in a downtown area, with urban valley effects. Given the actual field installation of underground pipelines, this study collected data via both conventional surveying methods and the Smart Station to evaluate the performance of the Smart Station. Analyzing the field data, this study examined the data collection time and position accuracy of an underground pipeline measured by the Smart Station. RESULTS : The field test results revealed that both the conventional surveying method and the Smart Station produced similar performances in data collection time and measurement accuracy in the open space test location. However, in the case of downtown locations affected by urban valley effects, the Smart Station achieved 100 % measurement accuracy while the conventional surveying method achieved 93 % accuracy. It was also observed during the field test that no data were collected due to the constraints of the work schedule and various field conditions (e.g., weather and/or traffic congestion). The data collection times at the open space locations were 10 s for both the conventional surveying method and the Smart Station. However, the data collection times at the downtown locations appeared to be 10 s and 360 s by the Smart Station and the conventional surveying methods, respectively, thereby proving that the Smart Station outperforms the conventional method in its measurement efficiency. CONCLUSIONS : It is envisioned that the Smart Station produces higher work efficiency for field operators as it enables them to collect high accuracy data in a timely and quick manner and not only build a database for the collected data but also vividly visualize it in the field. In the future, it is necessary to conduct additional field tests under various conditions for the in-depth investigation of a Smart Station. In addition, it is expected that the Smart Station will be enhanced by coupling augmented reality (AR) technologies.

In this study, the grid field olfactory odor method was supplemented to the domestic situation in the surrounding areas of a domestic science industrial complex. The actual condition of the occurrence of odor frequency in the field was then investigated over the first period of late spring to summer and the second period of autumn in 2017. The frequency of odor occurrence in the area around the science industrial complex was increased as odor discharge facilities in the nearby area were concentrated. The odor occurrence frequency of the total period was 0.09~0.28, that of the first period was 0.08~0.32, and that of the second period was 0.05~0.25. The odor occurrence frequency in summer was higher than in autumn. The frequency by which the measurement of odor occurrence by smell type was most dominant was mainly smell of chemicals, plastics, and livestock houses during the first period, and the smell of chemicals, burning gases, and plastics during the second period. And the frequency of each smell type was judged to be different according to season. The odor occurrence frequency was measured as higher than 0.15, which is the standard of Germany's odor frequency in an industrial area, and it was judged that measures for odor management in the region were necessary. Since most of the odor discharge facilities are non-continuous systems and the odor generation frequency is more important than the concentration of the minimum detection concentration, it was judged that the German grid method can reflect the odor occurrence characteristics of the odor complaints or receptors for a certain period of time compared to the domestic measurement method. In the future, it was judged that the field olfactory odor method would be able to replace the evaluation method of odor assessment in Korea with the survey method of odor assessment under actual conditions in areas where it is difficult to access the odor discharge source or the receptor where odor complaints occur.

This study was performed to evaluate the odor occurrence of offensive leather odor in a district in Gyeonggi-do, where Jeil industrial complex is located, and its residential district, by using olfactory field frequency measurement (Gird Method). In addition, we measured the composite odor. The target points were 9 spots in Jeil industrial complex and 12 spots in the residential district, and we conducted the measurements 13 times each spot. As a result, odor occurrence in descending order was investigated as follows, leather industry > drug industry > food industry. Moreover, odor exposure of the industrial complex exceeded the industrial zone standard of 0.15 (=German odor standard) in all 9 spots (average 0.78). In addition, odor exposure of the residential district exceeded the residential zone standard of 0.10 (=German odor standard) in 12 spots (average 0.78). All the composite odors were below 20 (industrial zone standard). However, as the odor intensity of the sampling site and the lab analysis data showed a large deviation, we found that much supplementation is needed of the odor analysis techniques in the equipment measurement methods.

In this study, we conducted a survey on odor characteristics of single odor and collective odor facilities using the German olfactory odor method and carried out the odor frequency modeling. The influence of the odor from a sewage treatment plant, which is a single discharge facility, was strong in the eastern and northern parts of the plant and appeared to be in good agreement with the areas where the odor complaints were frequent. The German olfactory method reflects the odor complaints and odor occurrence characteristics of the receptors as compared with the domestic odor measurement method. The influence of the odor from the odor control area, which is a collecting and discharging facility, showed a tendency in which the sum of the odor occurrence frequency increased with the proximity of the odor discharge facility to the dense industrial complex. Furthermore, it was judged that it is not easy to extract the odor frequency results for individual facilities because the survey subject is the group discharge facility area. Therefore, it will be necessary to introduce a method to manage odor in the future. In this study, the measurement of odor frequency using the German olfactory odor method is partially applied to some odor sources. Appropriately, it is not applicable to various emission sources. However, the odor measurement method based on odor occurrence frequency and odor sensory can be used for investigation of the actual condition, permits of odor discharge facilities and the environmental review.

Recently, advanced metering infrastructure (AMI) has been recognized as a core technology of smart water grid, and the relevant market is growing constantly. In this study, we developed all-in-one smart water meter of the AMI system, which was installed on the test-bed to verify both effectiveness and field applicability in office building water usage. Developed 15 mm-diameter smart water meter is a magneto-resistive digital meter, and measures flow rate and water quality parameters (temperature, conductivity) simultaneously. As a result of the water usage analysis by installing six smart water meters on various purposes in office building water usage, the water usage in shower room showed the highest values as the 1,870 L/day and 26.6 liter per capita day (LPCD). But, the water usage in laboratory was irregular, depending on the many variables. From the analysis of the water usage based on day of the week, the water usage on Monday showed the highest value, and tended to decrease toward the weekend. According to the PCA results and multivariate statistical approaches, the shower room (Group 3) and 2 floor man’s restroom sink (Group 1-3) have been classified as a separate group, and the others did not show a significant difference in both water use and water quality aspects. From the analysis of water usage measured in this study, the leak or water quality accident did not occur. Consequently, all-in-one smart water meter developed in this study can measure flow rate and water quality parameters (temperature, conductivity) simultaneously with effective field applicability in office building water usage.

해수 중 광학적 특성 때문에 유색 용존유기물은 위성자료에 기반한 해양의 엽록소와 일차생산력의 정확한 측정에 영향을 미칠 수 있다. 따라서 본 연구에서는 2009과 2011년 여름철을 대상으로 서로 특이하게 다른 결과를 보고하고자 하였다. 이 두 시기의 여름철 차이는 것은 용존유기물에 영향을 주는 주요 공급원이 다른 것으로 나타났다. 그리고 현장 측정치와 위성자료로 부터 얻어진 엽록소 농도를 비교하여 위성자료로부터 구한 엽록소 농도 측정에 대한 용존유기물의 영향을 보았다. 그 결과, 2009년 MODIS를 이용한 엽록소 농도와 현장 측정된 엽록소 a 농도는 서로 유사하였으나, 2011년과 같이 유색용존유기물의 농도가 높았던 시기에는 이 두 농도간에 유의한 차이가 나타났다. 2011년 여름 MODIS 자료와 비교하였을 때, GOCI 자료는 엽록소와 유색용존유기물 모두 현장 측정치 자료와 잘 일치하였다. 수직 혼합에 의해 공급된 표층 해수 중 높은 유색용존유기물의 존재는 위성자료에 의한 엽록소 농도의 과대평가에 영향을 주는 것으로 보인다.

PURPOSES: The objective of this study is to compare the densities of asphalt pavements measured both in the field and in the laboratory, and also to evaluate the applicability of field density measuring equipment, such as the pavement quality indicator (PQI), by using statistical analysis. METHODS: For the statistical analysis of the density measured from asphalt pavement, student t-tests and a coefficient of correlation are investigated. In order to compare the measured densities, two test sections are prepared, with a base layer and an intermediate layer constructed. Each test section consists of 9 smaller sections. During construction, the field densities are measured for both layers (base and intermediate) in each section. Core samples are extracted from similar regions in each section, and moved to the laboratory for density measurements. All the measured densities from both the field and laboratory observations are analyzed using the selected statistical analysis methods. RESULTS AND CONCLUSION : Based on an analysis of measured densities, analysis using a correlation coefficient is found to be more accurate than analysis using a student t-test. The correlation coefficient (R) between the field density and the core density is found to be very low with a confidence interval less than 0.5. This may be the result of inappropriate calibration of the measuring equipment. Additionally, the correlation coefficient for the base layer is higher than for the intermediate layer. Finally, we observe that prior to using the density measuring equipment in the field, a calibration process should be performed to ensure the reliability of measured field densities..

도로포장 노면 특성은 도로이용자의 주행쾌적성과 안전에 직접적인 영향을 미치는 중요한 요소이다. 노면 특성 중 평탄성은 도로포장의 대표적인 기능성 중 하나이며, 도로포장 상태를 판단하는 주요 지표이 다. 차량을 이용한 도로포장 평탄성 정량화 방법에 대한 본격적인 시도는 1960년대부터 시작되었으며, 다 양한 기법과 방식이 개발되었다. 이후 도로포장의 대표적인 평탄성 지수인 국제평탄성지수(International Roughness Index, 이하 IRI)로 통일되기 시작하였으며, 많은 국가에서 도로포장의 평탄성 정량화 지수 로 사용되고 있다. 최근 도로포장의 3차원 형상을 주행 중 취득할 수 있는 센서가 개발되어 기존의 2차원 적인 도로포장 표면 상태를 3차원 형상화가 가능해 졌다. 본 연구에서는 국내 최초로 도입된 노면3차원 프로파일 측정 장비를 이용하여 도로 평탄성 측정에 활용가능성을 현장시험를 통해 검증해 보았다. 시험 방법은 동일 구간에 대해 기준프로파일측정기(Reference Profiler)를 이용하여 측정된 IRI와 3차원 프로 파일 측정기에서 수집된 자료를 IRI계산 후 비교하였다.

PURPOSES : The purpose of this study is development of automatic equipment to measure the road water-reservoir which can be one of factors for road traffic safety inspection and its application to safety analysis. METHODS : The scopes of this study are the examination of the riskiness and location of road water-reservoir through literature review, development of appropriate sensor and automatic equipment to survey the road water-reservoir and evaluation of field application. RESULTS: The laser lighting and IR camera were selected to develop the equipment. It was found from the field calibration that there is a high correlation between rutting and road water-reservoir and road water-reservoir caused by rutting can be correctly calculated. About 20.2km of national highway were inspected for case study and field application. It was found from correlation of traffic incident that 2.08km of the latent length for water-reservoir which is related to 12 traffic incidents were analyzed. CONCLUSIONS : This technique can be utilized evaluation method for road condition such as road water-reservoir for conventional evaluation system such as road traffic safety assessment and safety analysis and it can be use to new evaluation system to apply various road condition and traffic condition.

최근 10년간 전세계적으로 아스팔트 포장을 재활용하는 기술이 급속도로 확산되고 있으며 노후 아스팔트 포장을 폼드 아스팔트 또는 유화 아스팔트를 사용하여 현장에서 바로 100% 재활용하는 현장 상온 재생 아스팔트 포장기술이 다양하게 적용되고 있다. 특히, 아이오와 주에서는 교통량이 적은 지방도로에서 기존 포장의 수명을 연장 시켜주는 현장 상온 재생 아스팔트 공법을 많이 적용하고 있다. 일반적으로 현장 상온 재생 아스팔트 포장층은 수분의 침투나 교통하중으로부터 보호하거나 포장설계를 만족시키기 위해 가열 아스팔트 포장으로 덧씌우기를 한다. 일반적으로 현장 상온 재생 아스팔트 포장층 위에 가열 아스팔트 포장으로 덧씌우기 할 시기는 대부분에 감독자들은 일정한 양생기간 또는 최대 함수비에 근거하여 결정하고 있다. 따라서, 본 연구에서는 감독자가 최적에 덧씌우기 아스팔트 포장 시기를 결정할 수 있도록 현장 상온 재생 아스팔트 포장층의 현장 함수비를 간단하게 측정하여 덧씌우기 시기를 결정할 수 있는 수분 감소계수를 개발하는 것이다. 먼저, 현장 상온 재생 아스팔트 포장층의 함수비를 TDR 함수량계를 사용하여 측정하였고 현장 상온 재생 아스팔트 포장이 시공되는 기간 동안에 강우량, 대기온도, 습도, 바람속도 등 기상정보를 수집하였다. 마지막으로 현장 상온 재생 아스팔트 포장의 초기 함수비, 대기온도, 습도, 바람속도를 변수로 하는 수분 감소계수를 개발하였다. 실제 현장 상온 재생 아스팔트 포장에서 측정한 값을 사용하여 개발한 수분 감소계수는 감독자가 연속적으로 현장 상온 재생 아스팔트 포장층의 함수비를 측정하지 않고 최적의 덧씌우기 포장 시점을 결정할 수 있다.

선진국의 기본 요건들 중 하나는 잘 정비된 교통인프라라 할 수 있을 것이다. 이러한 교통안전시설에 대해 해외에서는 각종 교통안전시설에 대해 객관적인 상태평가를 기초로 하여 시설을 관리하는 자산관리(Asset Management)측면에서 시설을 관리하고 있는 추세이다. 이 중 도로관련 각종 안전시설은 매우 다양하며, 기능 또한 매우 중요하기 때문에 이들에 대한 설치 규정 및 지침을 제정하고 있다. 그러나 설치기준 및 지침이 있음에도 불구하고, 각 시설이 기준에 부합되게 설치되지 않아 오히려 도로이용자에게 불편함 뿐 아니라, 안전에도 악영향을 끼치고 있다. 본 연구에서는 다양한 도로안전시설 중 도로의 설계(운영)속도 및 기하구조에 따라 설치 간격 및 높이들이 규정화 되어있는 시설에 대해 라인스캔카메라를 이용, 이를 신속하게 측정 가능한 영상분석 모델을 개발하였다. 또한 이를 체계적으로 분석할 수 있는 프로그램을 개발하여 현장에 적용하였으며, 그 결과 매우 정확하게 시설의 크기와 설치간격을 신속하게 측정할 수 있었다.