In this study, the operating performance of the heat pump dryer using the PF heat exchanger was experimentally studied. The capacity, COP, drain, SMER and operating status of the cooling cycle of the heat pump dryer were investigated according to the temperature, relative humidity and flow rate of the indoor air. Heat pump dryers are refrigerant-air system. For the dryer performance experiment, an air enthalpy calorimeter was used. From the experimental results, as the temperature, relative humidity, and flow rate of the inlet air increased, the capacity, COP, drain, SMER of the dryer increased. The change in the performance of the dryer was most affected by temperature. The P-h diagram of the cooling system showed that the operation status of the dryer was greatly affected by the indoor temperature. In addition, the SMER of the dryer showed a drying performance of about 3.38 kg/kWh or more within all experimental ranges.

본 연구는 돼지 간 거리(PD), 돈사 내 상대 습도(RRH), 돈사 내 이산화탄소(RCO2) 세 가지 변수를 사용하여, 네 개의 데이터 세트를 구성하고, 이를 다중 선형 회귀(MLR), 서포트 벡터 회귀(SVR) 및 랜덤 포레스트 회귀(RFR) 세 가지 모델 기계학습(ML)에 적용하여, 돈사 내 온도(RT)를 예측하고자 한다. 2022년 10월 5일부터 11월 19일까지 실험을 진행하였다. Hik-vision 2D카메라를 사용하여, 돈사 내 영상을 기록하였다. 이후 ArcMap 프로그램을 사용하여, 돈사 내 영상에서 추출한 이미지 안 돼지의 PD를 계산하였다. 축산환경관리시스템(LEMS) 센서를 사용하여, RT, RRH 및 RCO2를 측정하였다. 연구 결과 각 변수 간 상관분석 시 RT와 PD 간의 강한 양의 상관관계가 나타났다(r > 0.75). 네 가지 데이터 세트 중 데이터 세트 3을 사용한 ML 모델이 높은 정확도가 나타났으며, 세 가지 회귀 모델 중에서 RFR 모델이 가장 우수한 성능을 보였다.

Wall-embedded ventilators, which are commonly used for ventilation of buildings, greatly damage the aesthetics of the building due to pollutants such as dust and grease sticking to the fan and gaps of the ventilator as the period of use increases. For this aesthetic reason, it is often installed in a place that is not easily visible to people, and if the ventilation fan is not properly arranged and installed, it is difficult to maintain indoor air in an optimal state. In this study, the effect of the arrangement of ventilators on indoor ventilation performance was investigated. Comparisons were made between the case where three ventilators were concentrated and the case where they were spaced apart at regular intervals. It was found that the ventilation performance was different depending on the location where the ventilators were installed.

The objective of this study is to analyze the indoor air quality of multi-use facilities using an IoT-based monitoring and control system. Thise study aims to identify effective management strategies and propose policy improvements. This research focused on 50 multi-use facilities, including daycare centers, medical centers, and libraries. Data on PM10, PM2.5, CO2, temperature, and humidity were collected 24 hours a day from June 2019 to April 2020. The analysis included variations in indoor air quality by season, hour, and day of the week (including both weekdays and weekends). Additionally, ways to utilize IoT monitoring systems using big data were propsed. The reliability analysis of the IoT monitoring network showed an accuracy of 81.0% for PM10 and 76.1% for PM2.5. Indoor air quality varied significantly by season, with higher particulate matter levels in winter and spring, and slightly higher levels on weekends compared to weekdays. There was a positive correlation found between outdoor and indoor pollutant levels. Indoor air quality management in multi-use facilities requires season-specific strategies, particularly during the winter and spring. Furhtermore, enhanced management is necessary during weekends due to higher pollutant levels.

Herein, the present work focuses on the effective counter electrode for dye-sensitized solar cells. The bottom–up approach was adapted to synthesize Mn2O3 nanorods via the hydrothermal method and the reduced graphene oxide was merged with Mn2O3 to prepare a nanocomposite. The prepared nanocomposites were subjected to physio-chemical and morphological characterizations which revealed the crystalline nature of Mn2O3 nanorods. The purity level rGO was characterized using the Raman spectrum and the Fourier transform infrared spectroscopy employed to find the functional groups. The morphological micrographs were visualized using SEM and TEM and the high aspect ratio Mn2O3 nanorods were observed with 5–7 nm and supported by rGO sheets. The electrocatalytic nature and corrosion properties of the counter electrode towards the iodide electrolyte were studied using a symmetrical cell. The as-synthesized nanocomposites were introduced as counter electrodes for DSSC and produced 4.11% of photoconversion efficiency with lower charge transfer resistance. The fabricated DSSC devices were undergone for stability tests for indoor and outdoor atmospheres, the DSSC stability showed 93% and 80% respectively for 150 days.

목적 : 본 연구는 국민건강영양조사 제8기(2019-2021) 원시자료를 이용하여, 생체지표를 통한 휘발성 실내환 경요인(휘발성 유기 화합물, VOCs)과 백내장의 연관성을 파악하고자 하였다. 방법 : 백내장 의사진단 여부 및 가정 실내공기질 측정에 참여한 만 40세 이상의 성인 총 1,150명을 대상으로 하였다. 일반적 특성에 따른 휘발성 실내환경요인의 농도와 백내장의 유 ‧무에 따른 휘발성 실내환경요인의 농도를 비교하기 위해 복합표본 기술통계 분석과 로지스틱회귀분석을 하였다. p<0.050인 경우 유의한 것으로 판단하였다. 결과 : 대부분의 실내 휘발성 환경오염물질의 생체지표는 백내장을 진단받은 대상자에서 높게 나타났다. 특히 Benzene, Xylene, Acrolein, 1-Bromopropane, 1,3-Butadiene의 생체지표 평균농도(GM)가 백내장 진단받은 대상자들이 유의하게 높게 나타났다. 연령, 성별, 결혼, 알콜, 흡연, 소득을 보정한 복합표본 로지스틱회귀분석에 서, 1,3-Butadiene의 생체지표는 약 2배(OR 1.905(95% CI: 1.001, 3.625))의 위험도로 백내장에 영향을 미칠 수 있는 것으로 나타났다. 결론 : 본 연구는 기존에 밝혀지지 않은 휘발성 실내환경요인과 백내장의 연관성을 파악함으로써, 일부 휘발성 실내환경물질은 백내장의 원인물질로 작용할 수 있는 가능성을 보여주었다.

식물의 흡수를 통한 공기오염물질 제거는 생육 상태에 따라 그 효과가 달라진다. 실내에서 토양수분의 공급은 식물의 생 육을 위한 기본적인 관리 사항이다. 따라서 본 연구는 토양수 분함량에 따른 생리적 반응이 가스상 공기오염물질인 톨루엔 저감에 미치는 영향을 구명하고, 최적의 생육과 공기 정화 효 과를 위한 적정 토양수분함량을 찾고자 수행하였다. 이를 위 해 스파티필름과 파키라를 사용하여 40일 동안의 평균 토양 수분함량을 25%, 20%, 15%, 10%로 처리한 후 양자수율, 광 합성률, 기공전도도, 증산량 등 생리적 지수와 엽면적당 톨루 엔 저감량을 측정하였다. 그 결과 스파티필름은 토양수분함량 을 20~25%로 관리할 때 생육이 양호하고 최적의 톨루엔 저 감 효과를 얻을 수 있을 것으로 판단되며, 10% 이하 건조에 대한 주의가 요구된다. 반면 파키라는 토양수분함량 20% 이 하 처리구에서 톨루엔 저감량이 증가하였으나 10% 처리구에 서 생장량이 저하될 가능성이 있으므로, 공기 정화와 생육을 위한 최적 토양수분함량은 15~20% 범위이며, 25% 이상으로 장기간 유지하는 것은 과습을 유발할 가능성이 있는 것으로 판단된다.

Passengers on public buses operating in the metropolitan area are exposed to the closed indoor air for minutes to hours. The indoor air quality of buses is mostly controlled through ceiling-mounted ventilation and filtration devices. A simulation study using a commercial code was conducted for fluid flow analysis to evaluate the potential effectiveness of an air purifier that can be inserted into bus windows to supply clean air from the outside to the inside. As a result of field measurements, the average CO2 concentration inside the bus during morning and evening rush hours ranged from 2,106±309 ppm to 3,308 ± 255 ppm depending on the number of passengers on board. This exceeded the Guideline for Public Transportation. The optimal installation position of an air purifier appeared to be the front side of the bus. In fact, even a low diffusing flow velocity of 0.5m/s was effective enough to maintain a low concentration of CO2 throughout the indoor space. Based on numerical analysis predictions with 45 passengers on board, the maximum CO2 concentration in the breathing zone was 2,203 ppm with the operation of an air purifier.

Recently, there are some outdoor floor advertising lighting devices as one of the active marketing methods. However, for outdoor use, there are many restrictions due to the Outdoor Advertisement Act, according to requiring high-output heat generation, waterproofing, and AC power, etc. The purpose of this study is to develop a Duo Light product optimized for indoor use through publicity and information guidance in normal times and automatic evacuation route guidance display in case of disaster, in conjunction with disaster safety. To that end, patent search and patent association analyses were conducted, and a comparative analysis with commercial products was conducted as a case study. In addition, prototypes were designed and produced through the review of operation principles, where field environment surveys and self-tests were conducted. Also, technology roadmaps were presented by preparing plans for expandability and advancement of products. For the analysis of technology commercialization, the feasibility of technology commercialization was examined through the analysis of Jolly’s Model and Lean Canvas Model. The results of this study will be able to contribute to minimize human damage through the effective response to disasters, which can increase the effect of indoor advertising by using the proposed indoor floor advertising lighting device in advertising and disaster situations.

The purpose of this study was to determine the conditions necessary for the total eradication of mite pests in indoor environments. The study involved the construction of a sterilization experimental setup. For this setup, various sterilization techniques, such as UV-C, ozone, ultrasound, and heat were applied, based on previous research. The experimental procedure consisted of placing mite pests in a chamber and subjecting them to different sterilization techniques. Observations were conducted immediately after the experiment and repeated five days later to assess the extent of eradication. The results showed that UVC, ozone, and ultrasound methods were not successful in completely eradicating the mite pests. In contrast, heat sterilization demonstrated effectiveness depending on the specific temperature and exposure time. To achieve the eradication of mite pests in indoor environments, it is necessary to maintain conditions of short-term high-temperature sterilization above 65°C or sustain temperatures above 50°C for a minimum duration of 90 minutes.

In this study, a survey focusing on the status of clothing interest, inconveniences resulting from clothing, preferred design items, etc. was conducted on 364 elderly women to suggest aesthetically and functionally appropriate indoor wear design for at home elderly women aged 60 years or older. The survey results showed that in general, the respondents’ interest in clothing was high, and more respondents in their 70s or older had difficulty in the action of opening and closing. With respect to considerations when purchasing clothes, color was considered more important than design as respondent’s age increased, and size was regarded as the most important factor especially among those in their 80s. The preferred top styles were T-shirts and blouses among those in their 60s and 70s, and T-shirts and shirts among those in their 80s. The preferred sleeve lengths were “below the elbow” and “above the wrist” in all age groups. The preferred sleeve hem type was “tightening” in all age groups. The most preferred bottom styles were “straight-leg pants” and “elastic waistband.” This study suggests the design items of indoor wear, including top, bottom, and overgarment for warmth, appropriate for elderly women at home based on the survey results. The study results are expected to serve as basic data necessary for the revitalization of the clothing industry for elderly women.

This study was carried out to examine the concentration and distribution characteristics of total airborne bacteria (TAB) and airborne mold in non-regulated public-use facilities. The arithmetic mean (AM) of the TAB in all facilities was 356.5 ± 419.3 CFU/m3, and the geometric means (GM) was 157.8 CFU/m3, which did not exceed the standard value of 800 CFU/m3. The highest concentration was 637.3 ± 372.0 CFU/m3 (GM: 534.9 CFU/m3) in the underground shopping mall. The AM of airborne mold in all facilities was 448.2 ± 429.6 CFU/m3 (GM: 285.4 CFU/m3), which did not exceed the standard value of 500 CFU/m3, but was close to it. In particular, subway station (AM: 661.5 ± 441.2 CFU/m3, GM: 540.0 CFU/ m3), large-scale store (AM: 587.6 ± 683.2 CFU/m3, GM: 297.8 CFU/m3), and private educational institute (AM: 528.8 ± 379.6 CFU/m3, GM: 373.7 CFU/m3) exceeded the standard. Operational taxonomic unit of 16S rDNA and ITS2 rDNA region was analyzed to profile bacteria and mold component in the air of the public-use facilities. As a result, Pseudomonas and Morganella are the major bacterial groups. Regarding mold, Aspergillus, Candida, Malassezia, and Penicillium are the major groups. Component of each airborne bacterial and mold groups varied depending on the type of public-use facilities.

This study aimed to verify the validity of the evaluation items and weight determination of the indoor environmental safety area, which has the most frequent accidents, among the safety certification evaluations of educational facilities by the Ministry of Education of the Republic of Korea, which has been conducted since May 2021. As a preceding study, the evaluation items of the school safety evaluation checklist being implemented in the US state of Vermont were compared, and the causes of accidents judged by teachers in the accident experiences written by 200 Korean teachers were compared with the safety certification evaluation items belonged to the Ministry of Education. In addition, research literature using the AHP analysis technique on safety risks of elementary and secondary schools in China and safety evaluation index study cases of 539 elementary school children in Indonesia were analyzed. Through these preceding studies, measures to add and adjust evaluation items were derived and the validity and importance rankings of evaluation items were calculated through AHP questionnaires to teachers and safety experts. In addition, a survey was conducted on 104 ordinary people to verify the results of expert analysis. As a result of expert AHP analysis, 'safety education and disaster response training (.396)' was the highest priority for the relative importance of the first layer, followed by 'safety measures (.387)' and 'building materials'. Safety (.216)' was found to be the highest priority. In the overall importance ranking of the 13 second-tier screening items, safety accident prevention education had the highest priority and disaster preparedness training ranked second, proving that the Ministry of Education's review weight was underestimated. In addition, slip and collision accident countermeasures, which were not in the existing Ministry of Education review items, ranked 4th, laboratory practice room safety measures ranked 6th, and sanitation, cleanliness, hazardous substance management, and cafeteria/cooking room safety measures ranked 9th, indicating a significant level of importance. Referring to the importance ranking, which is the result of this study, it is suggested that it is necessary to review the weight of each review item again.

In this study, we present an algorithm for indoor robot position estimation. Estimating the position of an indoor robot using a fixed imaging device obviates the need for complex sensors or hardware, enabling easy estimation of absolute position through marker recognition. However, location estimation becomes impossible when the device moves away from the surrounding obstacles or the screen, presenting a significant drawback. To solve this problem, we propose an algorithm that improves the precision of robot indoor location estimation using a Gaussian Mixture Model(GMM) and a Kalman filter estimation model. We conducted an actual robot operation experiment and confirmed accurate position estimation, even when the robot was out of the image.

Vulnerable populations in healthcare facilities are more sensitive to exposure to indoor air pollutants, and therefore are more affected by such pollutants than the general population. This was the underlying reason why studies of indoor air pollutant concentration distribution and health risk assessment have been conducted targeting facilities, such as daycare centers, medical facilities, elderly care facilities, and postnatal care centers. However, previous studies have mainly focused on daycare and medical facilities for their research, and relatively speaking, studies conducted on the other venues are lacking. Therefore, this study aims to present the current status of indoor air quality and perform a health risk assessment in regard to Formaldehyde exposure at postnatal care centers and elderly care facilities. Here, the study focused on facilities that had undergone pollution level inspections from January 2017 to December 2021. A total of 81 postnatal care centers and 48 elderly care facilities were selected as the subject of the study. Then, the study utilized concentrations of five elements (CO2, HCHO, PM10, PM2.5, TBC) to determine the status of indoor air quality of both postnatal care centers and elderly care facilities. For health risk assessment, HCHO concentration was used. The investigation demonstrated that the yearly average concentration of the five elements stood within the indoor air quality maintenance standards, and the ratio of PM2.5 to PM10 in the two types of facilities was distributed as high as about 70%. In addition, the study showed that HCHO and TBC demonstrated a positive correlation when the relationship between indoor temperature and humidity with the five elements was examined. The health risk assessment showed that the cancer risk level of postnatal care center users stood below 10-6, below the level that is perceived as an acceptable risk. The cancer risk of workers from both postnatal care centers and elderly care facilities and elderly care facility users exceeded the acceptable risk level of 10-6, but was shown to be below 10-4, the maximum acceptable risk.