• 생명과학회지
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• 제34권4호
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• pp.264-270
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• 2024

본 연구는 평택시 죽백동 일원에 서식하는 맹꽁이를 2019년에 대체서식지로 이주시킨 후 2020-2022년까지 사후모니터링을 통해 대체서식지가 갖춰야 할 최소 조건과 맹꽁이 모니터링의 효율성 제고를 목적으로 진행되었다. 대체서식지의 서식 환경을 분석한 결과 습지, 초지, 하천과의 거리는 5 m 이내, 저층 초지 공간은 6,000 m² 이상, 깊이 20 cm 이상의 부드러운 토질, 임시 습지의 면적은 5,000 m² 이상으로 서식지 적합성 기준에 부합하였으며, 모니터링 과정에서 이주된 개체군의 체장길이 및 몸무게가 유지되는 것을 확인하여(p>0.05) 서식지와 산란지의 근접성, 먹이공간(초지공간) 확보, 토질, 습지의 조건이 갖춰진다면 대체서식지의 기능을 수행할 수 있는 것으로 나타났다. 맹꽁이 개체군에 영향을 주는 기상요인을 분석한 결과, 체장길이는 최저기온, 최고기온, 상대습도, 강수량과 통계적으로 유의미 하였다(p<0.05). 개체수 및 번식의 경우 강수량과 번식에서 유의미한 정(正)의 상관관계가 나타났으며(p<0.01), 개체수는 평균기온, 최저기온, 상대습도에 영향을 받는 것으로 나타났다(p<0.05).

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2001년도 하계 학술대회 논문집
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• pp.53-58
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• 2001

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.851-852
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• 2010

• 한국정밀공학회지
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• 제27권1호
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• pp.76-83
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• 2010

There have been many studies regarding development of autonomous excavation system which is helpful in construction sites where repetitive jobs are necessary. Unfortunately, bucket trajectory planning was excluded from the previous studies. Since, the best use of excavator is to dig efficiently; purpose of this research was set to determine an optimized bucket trajectory in order to get best digging performance. Among infinite ways of digging any given path, criterion for either optimal or efficient bucket moves is required to be established. One method is to adopt work know-how from experienced excavator operator; However the work pattern varies from every worker to worker and it is hard to be analyzed. Thus, other than the work pattern taken from experienced operator, we developed an efficiency model to solve this problem. This paper presents a method to derive a bucket trajectory from optimization theory with empirical CLUB soil model. Path is greatly influenced by physical constraints such as geometry, excavator dimension and excavator workspace. By minimizing a energy function under these constraints, an optimal bucket trajectory could be obtained.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.734-743
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• 1993

The performances of three same type of vibrating potato diggers were estimated by observing the potato separation and material flow on the bottom plate. Four-bar mechanism were adopted for three diggers and pairs of eccentric cams on both sides of driving shaft were used as driving link of the diggers. Each machine was tested with different amplitudes , frequencies, and travels speeds. Blade performance were observed in three categories : Impossible forward travel , acceptable operation, and unsatisfactory potato digging , but good material flow. Three parameters were used to set marginal values that enable the machines operate for potato digging, and the parameters were compared to select best one. Three parameters are λ, $\rho$, and K.λ is the ratio of vibrating speed to travel speed, $\rho$ is the ratio of blade acceleration to travel speed, and K is the ratio of blade acceleration to gravitational acceleration. K value of 2 or more is suggested to be used as design and evalu tion criterion of the vibrating digger.

• 영어어문교육
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• 제15권3호
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• pp.315-332
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• 2009

The purpose of this paper is to scrutinize how Parks recalling, deconstructing and reconstructing African-American memories of the absences in American history through a black Lincoln impersonator named, The Foundling Father or The Lesser Known. Parks unearths and reconstitutes a significance for the historical event of Lincoln's assassination by repetitive mimicry and verbal puns. As a pun of the Founding Father, the Foundling Father reminds us of Abraham Lincoln, one of the most venerated figures in American history. In the first act, the black Foundling Father performs as The Great Man. This inverted minstrel show of the black Foundling Father performing a white Lincoln exposes the desire of the Foundling Father to insert his narrative within the history of America. With a series of assassinations, the African-American performers figuratively murder the power and control of the American myth. In the second act, his wife Lucy and his son Brazil dig relics from the past out of 'The great hole of history' instead of the Foundling Father. Digging and burial for African-Americans are their livelihood and their calling as well. As Parks pointed out, they should locate the ancestral buried ground, dig for bones and find bones because so much of African-American history has been unrecorded, dismembered and washed out. Parks leaves the possibilities of digging and burying on the black history through Lucy and Brazil.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.576-579
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• 1997

In order to repair sewage pipes, it is necessary to dig up the damaged sewage pipes, which results in traffic jams. Since digging up the pipes takes too much time and cost, this method is inefficient. So, in stead of digging up the damaged pipes, a robot is sent down to the pipe to do the repair works. For big pipes, human workers go into the pipe and do to repair works, but for small pipes, it is impossible for human worker to go inside the pipe. In this case, mobile robots have used. The procedures for repairing pipes are as follows : First, the condition of the sewage pipes is observed by a robot. Second, appropriate steps for repair are determined according to the types of the damage. While repairing procedures, a newly-developed packer is sent into the sport to be repaired inside the pipe. Then, the packer is filled with air by a V-shaped wrinkel pipe. This makes the packer inflates uniformly and adhere closely to the inside wall of the pipe in large area. This increases the area that can be repaired. Therefore, the newly-developed packer will be very helpful for sewage pipe repair works.

• 대한토목학회논문집
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• 제36권2호
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• pp.325-332
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• 2016

적합한 굴삭기 부착 작업 장치들과 엔진크기의 구성은 굴삭계획 전에 결정되어야한다. 기존의 경험에 근거하는 굴삭기 구성선택 관습은 다양한 변수들을(장비 동작데이터, 토사유형과 상태, 버킷 속성들, 작업조건 등) 동시에 그리고 시기적절하게 고려하지 못하기 때문에 과학적으로 타당한 근거가 부족하다. 따라서 본 논문은 이러한 기존의 방법을 보완하기 위해 가장 합리적인 굴삭기 구성을 판별하는 새로운 굴삭기 구성 탐색 방법을 제안한다. MATLAB을 사용하여 구현 된 본 방법은 생산성의 변동을 일으키는 변수들을 고려하여 최적 굴삭기 구성을 규명한다. 본 방법론을 검증하기 위해 사례연구를 수행하였다.

• 화약ㆍ발파
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• 제22권3호
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• pp.97-101
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• 2004

건설현장에서 도로개설, 터널굴착, 시가지 고층건물 지하굴착 등으로 화약류의 사용은 날로 증가되고 있으며, 이로 인한 화약류의 사고도 비례하여 증가하고 있어 점차 사회문제화 되고 있다. 본 연구에서는 이미 개발된 발파사고의 분석에 필요한 사고조사표와 이를 이용하여 발파사고를 체계적으로 분석한 FTA기법 분석에서 발파사고 중 가장 많은 비율을 차지하는 인적원인에 대한 체크리스트를 개발하였으며, 이를 이용한 현장에서의 적용에 대한분석을 실시하였다. 그 결과 발파작업 중 가장 힘들고 불편한 공정인 장전작업에서 가장 많은 오류가 발생하였으므로 이에 대한 개선 작업에 관심을 기울여야 할 것으로 생각된다.

• Agricultural and Biosystems Engineering
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• 제5권2호
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• pp.40-44
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• 2004

This study was conducted to solve the problem of spinach harvesting done by manpower at the outdoor field during the cold winter season. Prototype spinach harvester was designed to dig, pick-up, and collect in a continuous operation for harvesting outdoor field-planted crawling type spinach. In the field test, two types of blades (Type A : angle of $150^{\circ}$, Type B : straight) were used for measuring the cutting loads of spinach and chain conveyor with lugs was used for picking up the root cut spinach. Prototype's vibrating blade reduced the digging power of the fixed blade by $46\%$. The loss was also very little ($0.7\%$) with a digging depth of 4 cm, an oscillation frequency of 748 rpm, and an oscillation distance of 33 mm. The working performance of the prototype spinach harvester was 38 hour/ha resulting to $96\%$ labor cost reduction compared to the conventional harvesting.