In this study, we learned about the effects of indoor radon concentration reduction associated with the operation of a mechanical ventilation system at an apartment house. The experimental parameters were mainly the indoor radon level and air change rate, which were controlled by the amount of emissions released and fan motor speed. Even at the high level of radon diffused in an apartment house, indoor radon concentrations converged to the Korean national guideline level within 3 to 4 hours when the air was ventilated at 0.5 ACH and 0.7 ACH. In the case of 0.3 ACH, however, where the degree of ventilation was insufficient compared to the legal air change rate, the high concentration indoor radon could not be sufficiently removed even if the mechanical ventilation system was operated for more than 14 hours continuously. When the indoor radon level was high, the reduction rate was 34.3% for 0.3 ACH, 70.4% for 0.5 ACH, and 69.7% for 0.7 ACH at 6 hours-operation, while at the medium-level, indoor radon can be reduced by 46.2% (0.3 ACH) to 73.2% (0.7 ACH). Depending on the indoor concentration range, it may be required to secure a ventilation rate of 0.5 ACH or more at all times. In addition, in apartment houses with excellent airtight performance, even if indoor radon is at a level similar to the national guideline, it is difficult to expect a reduction in the concentration due to natural decay. Therefore, it is desirable to lower the indoor concentrations as much as possible.

This study was designed to verify what effect the use of a natural ventilation system can have on improving indoor air quality with regard to radon in various concentration ranges in an apartment house. The results show that both high (2~3 times higher than 148 m3) and low (similar to 148 Bq/m3) levels of indoor radon concentrations can be reduced close to and/or below the Korean IAQ guideline within 6 hours when the natural ventilation system is operated at approximately an air change rate of 0.5. In the case of an air change rate of 0.3, however, the indoor radon levels cannot meet the national guidelines and the reduction effect was insufficient with regard to various radon concentrations. Typically, the air change rate of a natural ventilation system is affected by meteorological factors such as temperature, relative humidity, wind speed, pressure. Its effectiveness varies according to such factors, for that reason, the reduction effects on radon did not increase proportionally with the ventilation time in this study.

This study aimed to investigate the characteristics of odor-causing substances in Yeosu national industrial complex, which is designated as an “Odor management Area,” in 2019 and the surrounding area. The sampling sites were divided into three areas: five sites within the industrial complex (Management area), one site within the borders of the complex (Boundary area), and two sites within residential areas (Affected area) affected by odors. The odor compounds were collected from March to September at dawn, daytime, and night. The analytical items were meteorological data, complex odor, legally-designated 22 odor compounds and other VOCs. Complex odor was exceeded on the limit three occasions at two sites in the management area. Ammonia, two types of sulfides, three types of aldehydes, and five VOCs were detected to be within the emission standards. Ammonia was the most frequently detected compounds. Aldehydes and sulfur compounds made a relatively high contribution to the level of odors. Therefore, aldehydes and sulfur compounds should be reduced first in order to prevent odors from occurring.

The cooking-generated particles are major indoor sources of air pollution. Recently, the performance of the range hood is focused on particle removal performance. Range hood with an auxiliary air supply system can improve the fine and ultrafine particles removal efficiency by making a supply air during cooking activities. The particles were measured in the experimental building by varying ventilation types. Only operating range hood during the cooking activities was not enough to reduce the cooking-generated particles. Despite operating range hood systems, fine and ultrafine particle concentrations were maintained when cooking was finished. The range hood with a make-up air supply system can reduce the indoor particle concentration below background conditions when those systems were operated after cooking. In this study, the assessment of cooking-generated particle removal efficiency of the range hood with an auxiliary air supply system was conducted. The removal efficiency of ultrafine particles showed trends similar to the removal efficiency of fine particles.

Outdoor air pollution with particulate matter has become more severe in Korea. Ambient particle concentration affects the indoor environment through various routes through building envelopes. In this study, we investigated particle exposure in residential buildings. Indoor and outdoor particle sources determined the indoor concentrations and particle exposure. This paper measured indoor particles and CO2 concentrations in two different apartment buildings and conducted the survey for 24 hours. The I/O ratio of the occupant awake period was higher than the asleep period. The I/O ratio in the awake period is 0.93-3.65, while the I/O ratio in the asleep period is 0.31- 0.76.Indoor peak events such as cooking or cleaning temporarily increase the I/O ratio and emit the indoor particle sources. Decay rate constant is 0.49-6.84 (1/h) in the indoor peak events during the operation of the exhaust hood and natural ventilation. The size range of 0.3-0.5 μm size is over half for the proportions of emitted particles (55.6%). Daily exposure is divided into indoor sources (45.2%) and outdoor sources (54.8%). We found the differences for the proportion of particle exposure. The ratio of daily exposure in particles for 0.3-0.5 μm size is 43.1 (indoor)/ 56.9 (outdoor) %. However, indoor sources are higher than outdoor sources for the ratio of daily exposure in particles for the 0.5-10.0 μm size.

This study was performed to assess particulate matter removal efficiency of domestic air cleaner products in a field condition. The assessment also included air cleaners with different air removal mechanisms. The particulate matter (PM2.5) removal test with a different air removal mechanism using air cleaners showed that the electrostatic precipitation technique showed better performance compared with HEPA filters and other types of systems. Its removal efficiency was almost 95% in one of our operation times in the given test condition. It was assumed that not only the type of removal system but also the individual design, supply and exhaust system, and the automatically controlled air volume are involved in the removal efficiency. With respect to the area of application, tests with air cleaners for 40 m2, 60 m2, and 80 m2 areas revealed that particulate matter removal efficiency increased with the air cleaner that had a broad area of application. However, particulate matter removal efficiency by air cleaners did not correspondingly increase with the increase of the area of application. Moreover, the installation location did not influence particulate matter removal efficiency. Our results are expected to be used as the basic information for indoor air quality improvement and prediction using air cleaners.

In this study, we investigate a seasonal underground market which is located under a semi-enclosed basement. Under such settings, there is difficulty in managing indoor air quality such as ventilation. Based on the result, we can improve the indoor air environment of the underground market. The underground market in Seoul was divided into four types according to its structural characteristics and the seasonal survey was conducted. In conclusion, we will develop a realistic improvement plan to improve the indoor air environment of the underground market by selecting the underground market through actual survey.

목적 : 본 연구의 목적은 안구운동이 동반된 주의력 훈련이 인지장애가 있는 뇌손상 환자의 주의력 및 인지능력 회복에 긍정적인 영향을 미치는 효과를 알아보기 위한 예비연구이다. 연구방법 : 인지장애가 있는 뇌손상 환자 7명에게 16주 동안 총 48회 안구운동이 동반된 주의력 훈련을 집중적으로 실시하였다. 중재 도구는 안구추적 연동형 주의력 훈련시스템인 컴퓨터 기반 인지재활 프로그램(Eye-tracking & ear system based Attention training System; EYAS)을 적용하였다. 중재 전후 인지능력의 변화를 알아보기 위하여 한국형 간이 정신상태검사(Mini-Mental State Examination for Korean; MMSE-K), 전산화 신경인지기능검사(Computerized Neuro-cognitive function Test; CNT), 운동시지각검사(Motor-free Visual Perception Test; MVPT)를 실시하였다. 결과 : 안구추적 연동형 주의력 훈련시스템으로 안구운동이 동반된 주의력 훈련을 참가자에게 중재 프로그램으로 적용한 후 주의력, 정보처리속도, 기억력 및 시지각이 향상되었다. 아이어스 중재 전보다 중재 후 MVPT 평균점수가 높았다(p<.01). MMSE-K 역시 평균 점수가 향상 되었다. 시각 주의력과 정보처리 속도에서 효과를 알아본 결과 CNT의 VCPT(Visual Continuous Performance Test)(p<.05)와 VCCPT(Visual Controlled Continuous Performance Test)(p<.01)에서 중재후가 중재전보다 평균점수가 높았다. 아이어스가 기억력에 긍정적인 영향을 미친다는 것을 CNT 평가를 통해 알 수 있었는데 CNT의 VST(Visual Span Test)(p<.01)와 DST(Digit Span Test)(p<.05)에서 평균점수가 향상되었다. 중재 후 VST 역순 검사에서는 평균값 상승이 있었고, DST 역순 검사에서는 중재 전후 평균값에서 유의한 차이를 보였다(p<.05). 결론 : 안구운동이 동반된 주의력 훈련은 인지저하가 있는 뇌손상 환자의 주의력, 정보처리 속도, 시지각, 기억력 향상에 긍정적인 영향을 준다는 가능성을 알 수 있었다. 안구운동은 주의력과 관련성이 있고, 주의력의 향상은 다른 인지능력에 긍정적인 영향을 줄 수 있다. 향후 연구에서는 구조화된 실험설계로 효과검증을 실시할 필요가 있다.

Virtual reality is one of the most popular technologies in the fourth industrial revolution. We suggest that virtual training using virtual reality would be more effective than existing training. Development of virtual trolley simulation content was done through Unreal Engine. Through the production of virtual reality content, we had developed a more advanced simulation development environment.

The purpose of this study is to analyze the distribution of Candida species in patients with oral disease and clarify the distinction of Candida culture test according to its isolation technique. 75 samples was isolated from 42 patients who visited Chonnam National University Dental Hospital due to oral disease from December 2015 to August 2016. For isolating the candida sampling, saliva sampling and oral swabbing were used. Acquired sampling was cultured in CHROMagar Candida Culture Medium, which indicates the candida species as color. Of the 42 patients, C. albicans was the most frequently isolated species in 39 patients. For 17 patients out of 21 who underwent saliva sampling and oral swabbing simultaneously, oral swabbing was quantitatively underestimated comparing to saliva sampling. 12 samples in 21 samples having particular Candida species were not isolated by oral swabbing. Considering the possibility of fungal infection in various oral disease, it is recommended to perform not only oral swabbing but saliva sampling when isolating Candida.

Background: In the stroke patients with the characteristics of hemiplegic gait, turning direction of the affected and unaffected side influences turning time. Therefore, it is important to investigate the walking response to turning directions in stroke patients. Objects: This study aimed to measure the walking time while turning direction in hemiplegic patients depending on balance ability measured by Berg Balance Scale. Methods: A group of forty-five subjects with stroke (Berg Balance Scale score≥46 were twenty-eight, Berg Balance Scale score≤45 were seventeen) were enrolled in this study. Subjects were asked to perform the Timed Up and Go test. Testing indications included two directions for turning in each subject. These indications were for turning toward the affected and unaffected side in stroke patients. The duration of total analysis duration, sit to stand phase, stand to sit phase, mid-turning phase, and end turning phase were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 45 points of Berg Balance Scale score. The significance level was set at ɑ=.05. Results: There were significant increase time in the analysis duration and end turning phase duration while subjects were turned the unaffected side in stroke patients that presented a Berg Balance Scale score≤45 (p<.05). However, the comparison between the affected side and the unaffected side in the stroke patients with Berg Balance Scale score≥46, revealed no significant differences of the measured parameters. Conclusion: This finding should be suggested in the specific definition of turning direction for evaluation with Timed Up and Go test in the Berg Balance Scale score≤45, and other intervention for hemiplegic patients need to be suggested the direction of turning during walking training program.

중규모 기상 모델을 이용하여 안개와 같은 미세규모 국지현상을 정확히 재현하는 것은 매우 어려운 실정이다. 특히, 수치모델의 초기 입력 자료의 불확도는 수치모델의 예측 정확도에 결정적인 영향을 미치기 때문에 이를 보완하기 위한 자료동화 과정이 요구되어진다. 본 연구에서는 WRF (Weather Research and Forecasting) 모델을 이용하여 낙동강 지역에서 발생한 여름철 안개사례 재현실험을 대상으로 중규모 기상 모델의 한계를 검증하였다. 중규모 기상 모델에서 초기 및 경계장으로 사용되는 KLAPS (Korea Local Analysis and Prediction System)와 LDAPS (Local Data Assimilation and Prediction System) 분석장 자료를 이용하여 수치모델 모의 정확도 민감도 분석을 수행하였다. 또한 AWS (Automatic Weather System) 자료를 이용한 자료동화(Four-Dimensional Data Assimilation)에 의한 수치모델의 정확도 개선 정도를 평가하였다. 초기 및 경계장 민감도 분석 결과에서 LDAPS 자료를 입력 자료로 사용한 경우가 KLAPS 자 료 보다 기온과 이슬점온도, 상대습도에서 높은 정확도를 보였고, 풍속은 더 낮은 수준을 나타내었다. 특히, 상대습도에 서 LDAPS의 경우는 RMSE (Root Mean Square Error)가 15.9%, KLAPS는 35.6%의 수준을 보여 그 차이가 매우 크 게 나타났다. 또한 자료동화를 통하여 기온, 풍속, 상대습도의 RMSE가 각각 0.3 o C, 0.2ms−1 , 2.2% 수준으로 개선되었다.

소면적 재배 작물인 머위는 최근 쌈채류 소비가 늘어남에 따라 생산량과 재배면적이 늘고 있으며, 전국 유통량의 70%가 충남 논산 지역에서 생산되고 있어 농민에게 소면적 재배작물임에도 중요한 소득원이 되고 있다. 충남 논산의 머위 연작 재배지에서 해충 종류를 조사한 결과, 현재까지 총 12종의 해충을 조사 할 수 있었다. 잎을 가해하는 주요해충으로는 미나리총채벌레, 진딧물류, 달팽이류 이었으며 미나리총채벌레는 잎에 은색광택의 피해흔적과 작은 반점을 형성하였고, 진딧물류의 경우 흡즙을 통해 생육에 저해를 일으켰고, 달팽이류의 경우 섭식을 통해 잎에 섭식흔이 남았다. 줄기를 가해하는 주요해충으로는 머위명나방 이었으며 머위명나방은 줄기 속을 파고들어 섭식하며 피해가 진행되어 잎이 시드는 증상을 나타냈다. 기타해충으로는 점박이응애, 복숭아혹진딧물, 온실가루이, 부채날개매미충, 애매미충류가 있는 것을 관찰 할 수 있었다. 본 조사는 노지에서 발생한 해충들이 시설재배지에 유입되어 큰 피해를 줄 수 있을 것으로 예측하고, 피해가 심해 경제적 손실여부에 영향을 주는 주요해충에 대해서는 분리하여 농약등록을 위한 기초자료로 사용할 계획이다.

The world energy crisis and the universal interest in comfort buildings are not only leading the thriving Passive House and Nearly Zero Energy House strategies but also encouraging the development of higher performance HVAC systems and alternative energy sources for occupants and sensible energy consumption. However, household appliances have been used to control the indoor environment such as humidifiers, dehumidifiers and air cleaners are became popular, occupants have come to rely on these appliances heavily and are overusing energy on indoor environment manage easily and quickly. In addition, the intense air tightness of current residential buildings makes possible to reduce harmful outdoor conditions but has made the indoor environment isolated from the outdoors. As well, climate change due to global warming and the urban heat island effect have broken the natural bond between humans and the environment. As high-rise, air tight buildings have become the most common residential building type in South Korea, occupants in high-rise residential buildings inevitably lose the chances to have the natural environment by the change of season to feel the warm sunlights of spring and the dry leafy smell on an autumn breeze. In this sense, regional weather data was analysed to establish comfort residential building strategies that commune with nature and o