In this paper, a survey on students’ perceptions of air pollution, particulate matter (PM) and indoor air quality (IAQ) in school classrooms was analyzed. A total of 174 students participated in the survey, where 127 and 47 participants were elementary school students and middle school students, respectively. The elementary school was located in a rural area of Korea, whereas the middle school was located in an urban area. The questionnaire of the survey was mainly composed of three parts: (1) students’ perceptions of air pollution, (2) students’ perceptions of IAQ in the classroom, and (3) students’ perceptions of how to improve IAQ in the classroom. Based on our study, the responses of the students for the given questionnaire showed an opposite tendency. The students in the rural area tended to have positive perceptions regarding IAQ in the classroom as well as air pollution, whereas the students in the urban area revealed negative perceptions for the same items. Our survey results can be used by school officials in order to maintain and improve IAQ in school classrooms based on the perceptions of the students.

Radon is a radioactive gas material, which is not detectable by humans because of the absence of color and odor. Radon gas can exist indoors through a number of pathways and long-term exposure to such material can affect the human body, which may result in serious health issues such as lung-cancer. It is thus essential to reduce and maintain indoor radon concentration in order that potential health risks from radon can be diminished. In order to achieve the aforementioned goals, it is requisite to utilize a practical detector which is capable of continuous radon monitoring. In relation to this, a recently developed prototype radon detector, i.e., RS9A, provides highperformance comparable to existing research-grade radon detectors for the purpose of continuous radon monitoring in the air. Furthermore, RS9A is a convenient piece of equipment for use by the public as it is compact in size and affordable. In this paper, we conducted continuous measurements of indoor radon concentrations by using sets of RS9A and evaluated the equivalence of RS9A in terms of quality assurance.

In this paper, we conducted a survey to reveal the general perception of parents toward outdoor air quality, particulate matter (PM), and indoor air quality (IAQ) at schools where their children attend. A total of 1,030 parents participated in this survey, where the age of their children ranged between 7 years to over 19 years of age. Each participant was either a member of a non-governmental organization (NGO) with a keen interest in air quality or an ordinary public panel member with less interest. The result of the survey indicated that the participants had a negative perception of air quality, and parents believed that the outdoor and indoor air is extremely polluted. The participants pointed out that they believe that the main reason for the pollution is due to particulate matter (PM) and school classrooms are the location where their children are exposed to PM the most. Based on our study, the majority of the participants prefer a mechanical ventilation system to reduce indoor air pollutants in schools. Our study should be referred to by school officials in order to maintain IAQ and as a way of addressing the concerns of parents who want to protect their children’s health.

Radon is known to be one of the representative carcinogen materials, and may cause severe health damage to the human body with long-term exposure. Without proper treatment such as natural and mechanical ventilation, indoor radon concentration tends to increase as time passes. In this aspect, it is necessary to maintain indoor radon concentration below the domestic indoor air quality (IAQ) management standard by continuous monitoring. However, the number of practical devices which can detect radon concentration is scarce and most of the existing devices are very costly. Among such devices, the RS9A, a prototype of a radon detector, detects indoor radon concentration and is priced significantly lower compared to other existing radon detectors. In this paper, we investigated the RS9A for the continuous detection of indoor radon gas and compared its performance to a commercially available radon detector (RadonEye). We measured indoor radon concentrations at two separate sites by using both detectors simultaneously. The indoor radon concentrations measured by the aforementioned detectors revealed a high correlation. Therefore, the RS9A can be considered as an appropriate candidate for use as a continuous indoor radon monitoring system.

이유자돈 시기에 자돈의 성장성적을 개선하기 위하여 자돈의 사료섭취량을 극대화하는 것은 중요 하다. 본 연구는 사료섭취량을 증대시키기 위한 방법으로써의 향미제의 사용이 이유자돈의 성장성적 및 혈액성상에 미치는 영향을 규명하기 위해 수행되었다. 평균 체중 6.43±0.955kg의 3원 교잡종 ([Yorkshire×Landrace])×Duroc) 160두를 공시하였으며, 4처리 5반복 펜당 8마리씩 성별과 체중에 따 라 난괴법으로 배치하였다. 처리구는 1)향미제를 첨가하지 않은 처리구, 2)밀크-바닐라향 0.3%를 첨가 한 사료 3)버터향 0.3%를 첨가한 사료 4)어분향 0.3%를 첨가한 사료이다. 실험결과 성장성적, 혈액성 상 및 설사지수에서 처리구간 유의적인 차이를 발견하지 못하였다. 따라서 향미제의 종류에 상관없이 향미제를 0.3% 첨가한 사료는 그렇지 않은 사료에 비해 이유자돈의 성장성적이나 혈액성상에 있어서 아무런 긍정적인 영향을 끼치지 않을 것으로 판단된다.

This experiment was conducted to evaluate the effects of migration frequency on growth performance, blood profile, pork quality and economical analysis in growing-finishing pigs. A total of 56 growing pigs [(Yorkshire×Landrace)×Duroc] with an initial body weight 28.01±4.09 kg were used in this experiment. Pigs were randomly allocated to one of two treatments in a randomized complete block design and 7 replicates with 4 pigs per pen. Experimental treatments were 1) 1 site: growingto- finishing at 1.24 m2/head, 2) 2 site: growing facility for 6 week at 0.81 m2/head followed by move to the finishing facility at 1.24 m2/head. Feeding trial was composed by two growing phase (0-3 week, 4-6 week) and two finishing phase (7-9 week, 10-12 week). As a result, different pig flows influenced on growth performance of growing-finishing pigs and 1 site treatment showed higher average daily gain, average daily feed intake, and G:F ratio on growing phase (0-6 week, p<0.01). The 2 site treatment showed higher serum cortisol level at week 6 (p=0.03). In carcass evaluation, 1 site treatment had shorter days to slaughter 110 kg body weight (p=0.01). Consequently, 1 site system had better performance and economical profits for swine farms.

Construction of roof structure, cable suspended structure, for Pusan main stadium is adapted a lifting method that is VSL lifting system. 5 processes are practiced for erection of the roof structure including the first lifting process for erection of upper cables and the second lifting process for erection of lower cables. Since all cables of this roof structure with two open spelter sockets are determined their length, some cable were wrong length, he roof structure would be unstable. But, At complete of erection for the roof structure each cable is attained to theoretical tension force with average 4% errors.