최근 유기농산물에 대한 선호가 증가하고 있다. 유기농산물 생산에 있어 물리적 제초는 필수적이다. 하지만, 국내 밭 제초작업 기계화율은 60% 미만으로 낮으며, 농촌 인구의 고령화·여성화로 소형 제초기의 개발이 필요하다. 또한, 제초기의 경우 사용자가 반복적 진동에 노출되기 때문에 이를 절감할 수 있는 노력이 필요하나, 이에 대한 연구는 미흡한 실정이다. 따라서, 본 연구에서는 여성·고령 농업인도 사용하기 편리한 전동 배부식 중경제초기를 개발하는 데 있어 수평 회전식 원판에 부착된 제초날의 형상(원형, 삼각형, 일자형) 및 폭(15, 20, 25mm)에 따른 제초성능 및 ISO5349-1에 따라 손에 전달되는 진동을 분석하였다. 제초율은 원형 제초날에서 90.4~96.4%로 가장 높게 나타났으며, 진동 또한 원형 제초날을 사용하였을 때 사용자의 10%가 수지백증이 발병하는데 걸리는 시간이 20년 내외로 삼각형 및 일자형 제초날을 사용했을 때 보다 200% 가량 증가하는 것으로 나타났다. 따라서, 원형 제초날을 사용하였을 때 진동을 감소시킬 수 있으며, 불필요한 반력을 줄여 높은 제초효과를 볼 수 있을 것으로 판단된다.
COVID-19가 전 세계를 강타하면서 각 국가는 대혼란에 빠졌다. 전 세계 화물교역은 80 % 이상이 해상운송을 통해 이루어지고 있어 화물과 여객을 포함한 해상운송업은 COVID-19의 큰 영향을 받는 산업으로 예측되었다. 따라서 본 연구의 목적은 코로나 팬데믹 (Coronavirus Pandemic) 발생 전후로 아시아 주요 항만 컨테이너 항구의 팬데믹 전후 운영효율성을 분석하는 것이다. 항만의 운영효율성을 분석하기 위해서 자료포락분석(DEA)을 이용하였다. 본 연구의 분석 기간은 5년(2016~2020년)으로 2016년, 2017년, 2018년, 2019년을 코로나 이전으로 하고, 2020년을 포스트 코로나 시대로 설정하였다. 또한, 분석 대상으로는 아시아 상위 10개 항구 중 동종 DMU의 DEA 요건을 충족시킨 상하이, 광저우, 선전, 닝보-저우산, 부산 및 싱가포르 총 7개 항구를 선택하였다. DEA의 CCR 및 BCC 모델의 결과는 몇 가지 비효율성이 확인되었음에도 COVID-19 팬데믹 발생 시점에서 몇 개월 이후부터는 전반적으로 운영효율성이 코로나 이전 몇 년 동안보다 상대적으로 높았음을 확인하였다. 하지만 일부 항만 (부산, 광저우)의 경우에는 더욱 나은 운영효율성을 위해서 항만의 규모와 운영의 기술적 능력 등을 제고 할 필요가 있다.
This study examines the Gyeongju Seokguram Grotto restoration project (1961-1962) by architect Kim Chung Up (1922-1988) and introduces the documents he wrote at the time of planning. The study highlights Kim’s Plan attempt to adopt Buckminster Fuller’s idea of the Geodesic Dome, while inheriting the architect Pai Ki Hyung’s previous design plan which was nullified. As Seokguram Grotto’s water leak and deterioration issues have been brought up, the four-times survey was carried out by experts team between 1958 and 1960, under Ministry of Education’s direction. Pai designed an initial restoration plan based on the survey’s result, which was a double-dome structure with a concrete film on the outer periphery as a way to protect Seokguram Grotto in January 1961. However, as drawbacks, such as the heavy load of the concrete dome, and non-installation of entrance hall, have been indicated in the review process, the Cultural Properties Committee rejected the plan. Subsequently, Kim was appointed as the supervisor of the second restoration project. Kim drew up a process management schedule to be implemented from August 1961 to December 1963 and designed the conception plans for the second restoration design. This study analyzes Kim’s Plan by examining sketches, site plans, floor plans, and sections. Kim planned to maintain the idea of the double-dome structure proposed by Pai while applying Buckminster Fuller’s idea of the Geodesic Dome. Kim planned to lighten the dome structure by applying a steel-frame Geodesic Dome so that the dome structure could be supported by its own. The study is expected to reclaim the omitted parts from Seokguram Grotto's historical description and Kim's careers.
PURPOSES : The purpose of this study was to develop the evaluation methodologies for spraying amount and sprayed condition of curing compound based on IoT technology when concrete pavements are constructed. METHODS : To measure the spraying amount of curing compound, a turbine type flowmeter was selected and a number of laboratory experiments were performed to verify the applicability of the selected sensor. To evaluate the uniformity of the sprayed curing compound on the concrete pavement surface, image process technologies were examined using pictures taken from the actual construction sites and from the test specimens. RESULTS : By performing experiments using water and curing compound, the selected flowmeter was verified to properly be applied to measure the spraying amount of curing compound with an acceptable accuracy. By conducting image processing using pictures of the sprayed curing compound on the concrete pavement surface, it was found that the 8 color analysis method was the best to evaluate the uniformity of the sprayed curing compound. CONCLUSIONS : From this study, it was concluded that the spraying amount of curing compound could be accurately measured using a turbine type flowmeter and the uniformity of the sprayed curing compound on the concrete pavement surface could be properly evaluated using an image processing technology.
Global warming affects critical natural resources, one of which is the oceans that occupy 70% of the total cover of the earth. In other words, ocean warming is a subset of global warming which needs to be addressed urgently. Purple laver (pyropia spp.) is one of the most vulnerable items to climate change although it is a major export product of Korean fisheries. The purpose of this study is to analyze the causality of how climate change caused by global warming affects the increase or decrease of PLP (purple laver production). The target area for analysis was set to Maro-hae between Jindo-gun and Haenam-gun. We selected marine environmental factors and meteorologic factors that could affect PLP as variables, as well as co-integration tests to determine long-term balance, and the Granger causticity tests. As a result, PLP and marine environmental factors WT (water temperature), pH, and DO confirmed that long-term equilibrium relationships were established, respectively. However, there is only causality with WT and it is confirmed that there is only a correlation between pH and DO (dissolved oxygen). There was no long-term equilibrium relationship between PLP and HDD (heating degree days) and there is a causal effect that HDD affects PLP; however, it was less clear than that of WT. The relationship between PLP and RF (rainfall), WS (wind speed), SS (percentage of sunshine), and FF (farm facilities) was all balanced in the long term, and causality exists. Based on the results of the analysis, policy proposals were made.