Overwintering and succession of phytoplankton community with physicochemical and biological characteristics were investigated in pilot culture system. Water and phytoplankton samples were collected twice a week from February 23 to June 28, 2016. A total of 17 overwintering taxa including cyanophyceae, chlorophyceae, bacillariophyceae were identified in the experimental group in winter (February), and these overwintering species showed a marked succession pattern along with environment changes. In the process of phytoplankton succession, a total of 56 species in 28 genera were identified in two (experimental, control) pilot culture system. In the experimental group, 52 phytoplankton species in 24 genera were identified, and the number of taxa was highest in chlorophyceae (35 species), followed by Bacillariophyceae (9 species), Cyanophyceae (5 species) and others (3 species). In the control group, 25 phytoplankton species in 14 genera were classified and these taxa consisted of 17 chlorophyceae, 3 cyanophyceae, 2 Bacillariophyceae and 3 others. The standing crops ranged from 40 to 325,450 cells mL-1 in the experimental group, and from 900 to 37,100 cells mL-1 in the control group, respectively. The dominant species were represented by Monoraphidium minutum, Microcystis aeruginosa, Rhodomonas lacustris, Ankyra judai and Chlorella vulgaris in the experimental group; and M. minutum and Coenochloris cf. pyrenoidosa in the control group. In conclusion, overwintering and succession of predominant phytoplankton species developed due to interactions of internal environmental factors (physicochemical and biological factors) in the pilot culture system.

In the construction sites, rush (speedy construction) work have recently been overused because of budget reductions by reducing the construction duration after the long-term economic recession and construction business stagnation with institutional change including the instruction of the duration shortening bidding system and the introduction of the post-construction sales system by the Korea Research Institute for Human Settlements. Due to this, negligent accidents have frequently occurred by forcing manpower, equipment, finance, and material procurement and pressing ahead with impractical construction wok at night according to the reduction of construction schedules. Therefore, this paper has the necessity of this study to seek for alternatives to prevent negligent accidents by finding factors related to rush work in the reality that the importance for preventing negligent accidents is more emphasized while they have not been reduced in construction sites.

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.

This study was conducted to test the green-tide mitigation technique in the lower part of the Sook Stream (Chusori) of Daecheong Reservoir from June 27 to August 24, 2014. And the effects were compared with weekly monitoring result of the watching station of the algae alert system (AAS) as well as test beds reach. The green-tide in a test bed was begun from the upstream, and it was gradually transferred and spread toward the downstream by the hydrological factors. The total amount of algae removed by algae removal device during the test period was 33,920 kg, and solids dewatered by natural gravity was 8,480 kg. Also chlorophyll-a content was 2.83 kg, the number of blue-green algae cells was equivalent to 78.6×1014 cells. Compared with the results of the watching station of AAS, the pre-concentrate removal work in the outbreak waters was able to suggest the possibility of green-tide mitigation. In addition, an effective management of the green-tide was required spatial and temporal occurrence information and practical device technology. Particularly, the optimal timing of algae removal in the river-reservoir hybrid system was recommended at times before the monsoon rainy season and reached the lowest water level.

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital singlelens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS: Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be 190 mcd/m2 at 30 min after sunset and approximately 10-12 mcd/m2 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.

OBJECTIVES : A fog generated field test was conducted to analyze the relationship between different sizes of variable speed limit signs and the legibility distance under various fog density conditions. By using this study, appropriate sizes of signs can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area for this test, as other places cannot maintain the fog condition because of rapid air current. A total 121 subjects were recruited for this test, which took place over the course of four days. The test on the first day was conducted under normal weather conditions for comparison. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between the different sizes of signs and the legibility distance corresponding to the visibility distance due to both non-fog and fog generated conditions. According to the technical test results, appreciable amount of reduction in legibility distance due to fog was resulted in all sizes of signs. Moreover, the legibility distance is reduced proportionately with the decrease in the visibility distance due to fog. CONCLUSIONS : The results of this study can be used to select appropriate sizes of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.

OBJECTIVES : A fog generated field test was conducted to analyze the relationship between the luminance of variable speed-limit signs and the legibility distance under various fog density conditions. By using this study, appropriate luminance values can be selected depending on the density of fog. METHODS: An actual tunnel was selected as the area to conduct the test, as other places cannot maintain the fog condition because of rapid air current. Ninety-two subjects were recruited for this test, which took place during the course of three days. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS: The test results show the relationship between luminance values and the legibility distance corresponding to the visibility distance due to fog. According to the technical test results, lower luminance value such as 7000 cd/m2 corresponds to less legibility distance compared to higher values such as 20000 cd/m2 or 40000 cd/m2. However, the amount of difference between 20000 cd/m2 and 40000 cd/m2 is negligible in our test. CONCLUSIONS: The results of this study can be used to select appropriate luminance of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.

Four fungal species, during indoor air monitoring for fungi that possibly affect the field testing of a newly bred shiitake cultivar in cultivation houses located in Cheongyang, Chungnam Province and Jangheung, Jeonnam Province. Of these species, two are known to be plant pathogens and the other two are saprobes but potent contaminators in the mushroom cultivation environment. This study reports the morphological characteristics and phylogenetic relationships of these four species based on nucleotide sequences of the internal transcribed spacer (ITS) and 18S rDNA region, including their known information.

본 연구는 교육현장에서의 변혁적 리더십이 교사의 일터영성(workplace spirituality)과 교사가 업무 및 학교생활을 통해 얻어지는 만족도와 학교조직과 학생 및 수업에 대한 애착의 정도를 나타내는 교사헌신 간에 미치는 영향에 대해 실증분석을 통하여 검증하는데 목적이 있다. 이를 위하여 전국의 초·중·고등학 교에 근무하는 교사들을 대상으로 설문지 409부를 회수하여 확인적 요인분석과 구조모형방정식을 이용하 여 분석을 수행하였다. 연구결과, 첫째, 학교장의 변혁적 리더십은 일터영성에 통계적으로 유의미한 정(+)적인 관계를 보이는 것으로 나타났다. 둘째, 일터영성은 소명의식을 제외하고는 교사만족 교사헌신에 모두 통계적으로 유의미한 정(+)적인 관계를 보이는 것으로 나타났다. 셋째, 일터영성은 학교장의 변혁적 리더십과 학생수업 헌신 간에는 완전매개 하는 것으로 나타났으며, 학교장의 변혁적 리더십과 교사만족 및 조직헌신 간에는 부분 매개 하는 것으로 나타났다. 본 연구는 일터영성이 학교조직성과에 중요한 변인임을 실증분석을 통하여 확인하였으며, 학교장은 교 사의 일터영성을 고양시키기 위하여 변혁적 리더십을 발휘하여 조직의 성과를 높여야 한다는 시사점을 제공하는데 의의가 있다.

Safety accident in Building construction work in the process of preparation and implementation of the insecure human, material status is often caused by combining the reality is that many things. Accident rate is a similar level in the case of Korea and foreign countries than any country in the measures by the higher fundamental prescription is needed. In this paper, construction safety management of subcontracting work and small construction plan to apply through a survey to reach a sensible alternative. I did In conclusion, the educated workers know well, and so on the work schedule then quickly if safety management personnel in disaster will be able to reduce the rate to a miracle appeared.