• 대한원격탐사학회지
• /
• 제37권6_2호
• /
• pp.1881-1890
• /
• 2021

미세먼지는 인체에는 물론 생태계, 날씨 등에도 많은 영향을 끼치며, 인구와 건물, 차량 등이 밀집된 대도시에서의 미세먼지의 예측과 모니터링은 중요하다. 특히 자동차, 연소 등에서 발생하는 PM_2.5 농도는 독성 물질을 포함할 수 있어 체계적인 관리가 필요하다. 따라서 본 연구는 화학 인자, 위성 기반의 aerosol optical depth (AOD), 기상 인자 등을 입력 자료로 하여 수도권PM_2.5 농도를 예측하고자 한다. PM_2.5 농도 예측을 위해 기계 학습 모델 중 PM 농도 예측에 우수한 성능을 보이는 random forest (RF) 모델을 선정하였으며, 모델 평가를 위해 통계 지표인 R², RMSE, MAE, MAPE를 산출하였다. RF 모델의 모델 정확도는 R², RMSE, MAE, MAPE는 각각 0.97, 3.09, 2.18, 13.31로 나타났으며, 예측 정확도는 각각 0.82, 6.03, 4.36, 25.79로 본 연구에서 사용한 인자들을 이용하여 PM_2.5를 예측 시 높은 정확도와 상관성을 나타내었다. 따라서 향후 학교 미세먼지 예측 및 범주화를 위해 본 연구에서 사용한 인자들을 RF 모델에 적용하였을 때 신뢰할만한 결과를 도출할 수 있을 것으로 기대된다.

• Journal of Nutrition and Health
• /
• 제31권2호
• /
• pp.179-191
• /
• 1998

The satisfaction of elementary school children and their parents with the school lunch program by foodservice system was assessed by questionnaire. 787 (347 male, 417 female) 5th grade elementary school children and 761 parents participated. Foodservice systems of the schools were of 4 types : central/commissary ; satellite /commissary ; conventional/contracted ; and delivery/contracted. The most joyful mealtime for children was identified as lunch because of eating with friends. Satiety and leftovers after lunch varied according to the foodservice system. For example , there was less satiety in the contracted system and more leftovers in the delivery system than in the others, Foods tasted better in the commissary system than in the contracted one. The contacted system , especially the delivery/contracted system, was poor for keeping rice and soup hot. The children's food habits such as eating a greater variety of foods and good table manner were improved through the school munch program. Most parents well understood the main purpose of the school lunch program to be a source of education on nutrition and table manner, as well as a way in which to provide the same meals to all students and save the time & work needed to prepare home lunches. Parents claimed that hygiene, taste, good nutrition and food amount should be improved. This was especially true for hygiene in the commissary system and taste in the contracted system. Furthermore, they stressed that better taste and hygiene are the most important criteria for good school foodservice systems. In conclusion, parents wanted the school lunch program should be selected with consideration of children's preference such as by periodical food preference tests. A nutrition education program should also be provided to correct bad food habits of childrens.

• Journal of Nutrition and Health
• /
• 제30권6호
• /
• pp.690-703
• /
• 1997

The purpose of this study were to analyze work function and labor productivity in school foodservice systems through work sampling methodology. Conventional foodservice were classified into 5 group depending on the number of meals served. Commissary school foodservices were also classified into 5 group by cluster analysis using the number of meals served, the number of satellite schools, and the duration of time for delivery of food. Work measurement through work sampling methodology was conducted in at 5 conventional and 21 commissary food -services during 3 consecutive days from September to October in 1995. Results from work measurement through work sampling methodology were as followed : The most prevalent work functions was cleaning (26.5%) and then processing (25.1%) in conventional while it was processing (30.9%) and then cleaning(25.2%) in commissary school foodservice. Delay was 22.9% and 19.7% respectively. Mean labor minutes per meal of conventional and commissary foodservics were 4.57 and 4.09 minutes, respectively : no significant difference in labor minutes per meal existed between the two systems. but mean labor minutes per meal of commissary foodsevices(1.79min) was significantly lower than that of conventional foodservice(2.33min) during work time before service (p<0.05). Productivity was significantly lower in foodservices which served less than 400 servings ; n significant differences existed among 401-70, 701-1,100 and 1,101-1,500 meals. The highest productivity was in conventional school foodservices which served 1,501-1,900meals. Labor minutes per meal of commissary school foodservice which served less than 400meals per day was significantly lower than those of foodservice which served 401-1,900meals (p<0.05). Labor minutes per meal, preparation and cleaning were positively correlation in two school foodservice systems.

• 교육녹색환경연구
• /
• 제14권3호
• /
• pp.28-37
• /
• 2015

1기 5개 신도시 초등학교 88개교를 조사 분석한 결과 나타난 주요 연구결과는 다음과 같다. 5개신도시중 학생수용률 최고점에 이르는 기간은 평균적으로 5.7년이 소요되었다. 90%이상을 유지한 구간 평균 수용률은 5.7년, 80%이상은 9.1년, 70%이상은 12.3년, 60%이상은 14.6년, 50%이상은 16.6년, 40%이상은 18.4년, 30%이상은 18.9년, 20%이상은 20.5년이 걸리는 것으로 나타났다. 이는 단기적인 민원해결차원에서의 학교내 학급 증설, 또는 추가 학교신설은 향후 유휴교실 발생의 원인이 되고 있어, 학교신설 과제의 단기적 해법이 아닌 20~30년의 장기적 관점에서 학생수 감소에 대비한 신설학교규모, 형태, 운영에 관한 다양한 해법의 모색이 필요하다. 본 연구는 1기 5개 신도시를 중심으로 이루어졌기 때문에 이를 일반화하는 데는 한계가 있어 전국적인 학생수 변동요인 전반에 걸친 추가적인 연구가 필요하다.

• Parasites, Hosts and Diseases
• /
• 제53권3호
• /
• pp.271-277
• /
• 2015

The genetic diversity of Schistosoma haematobium remains largely unstudied in comparison to that of Schistosoma mansoni. To characterize the extent of genetic diversity in S. haematobium among its definitive host (humans), we collected S. haematobium eggs from the urine of 73 infected schoolchildren at 5 primary schools in White Nile State, Sudan, and then performed a randomly amplified polymorphic DNA marker ITS2 by PCR-RFLP analysis. Among 73 S. haematobium egg-positive cases, 13 were selected based on the presence of the S. haematobium satellite markers A4 and B2 in their genomic DNA, and used for RFLP analysis. The 13 samples were subjected to an RFLP analysis of the S. haematobium ITS2 region; however, there was no variation in size among the fragments. Compared to the ITS2 sequences obtained for S. haematobium from Kenya, the nucleotide sequences of the ITS2 regions of S. haematobium from 4 areas in Sudan were consistent with those from Kenya (> 99%). In this study, we demonstrate for the first time that most of the S. haematobium population in Sudan consists of a pan-African S. haematobium genotype; however, we also report the discovery of Kenyan strain inflow into White Nile, Sudan.

• 항공우주정책ㆍ법학회지
• /
• 제29권1호
• /
• pp.97-126
• /
• 2014

October 4, 1957 the Soviet Sputnik 1 was launched into space the first time in the history of mankind. After launching, the realm of humankind was expanded to space. Today all countries of the world wage a fierce competition in order to utilize space for various purposes. World powers of space such as United States, Russia, China, and Japan, put reconnaissance satellites and ocean surveillance satellites into orbit, being able to easily see equipment and troops movement on earth. Each country makes efforts to occupy space assets through the militarization of space and expand national interests. Recently private companies or individuals involved in commercial space activities are becoming more prevalent. Thus, in addition to space activities for military purposes, commercial space activities become widespread. Individuals and private companies as well as nations are also involved in space activities. Outer space is not the monopoly of space powers such as the United States and Russia. The whole human race can benefit from free access to space, being the common heritage of mankind. In particular, outer space becomes an indispensable element of military activities and human life. Many countries are now entering space development, putting a lot of budget into new development programs. Republic of Korea also built the Narodo Space Center, starting its space development with budget and manpower. We have to find out ways to use space not only for military purposes but also for commercial space activities that can contribute to the national economy. In addition, through the joint efforts of the international community, we have to make efforts for preservation and peaceful use of space. Various issues relating to space activities and research should be studies in order to contribute to the progress of humanity. Those issues include the definition of outer space, space debris reduction and environmental conservation issues, non-bind measure cooperation - European International Code of Conduct, space law and national legislation related empowerment issues, arms control measures in space, and restrictions on the use of nuclear fuel. We also need to be involved in the discussion of those issues as one of responsible space countries. In addition, we try to find out regional cooperation schemes such as the ESA in the Europe actively. Currently in the Northeast Asia, cooperation bodies led by Japan and China respectively, are operated in the confrontational way. To avoid such confrontation, a new cooperative body needs to be established for cooperation on space exploration and information. The system to allow the exchange of satellite information for early warning of natural disasters needs to be built as well. In addition, efforts to enhance the effectiveness of the relevant international treaties on space, and fill in the blanks in international space laws should be made at the same time. To this end, we have to do a leading role in the establishment of standards such as non-binding measures (resolution) - Code of Conduct, being discussed in the UN and other organizations, and compliance with those standards. Courses in aerospace should be requires in law schools and educational institutes, and professional manpower need to be nurtured. In addition, the space-related technology and policy needs to be jointly studied among the private, public, and military groups, and the cross exchange among them should be encouraged.