• 수산경영론집
• /
• 제46권3호
• /
• pp.129-141
• /
• 2015

Because land based aquaculture is restricted by high investment per rearing volume and control cost, good management planning is important in Land-based aquaculture system case. In this paper master production planning was made to decide the number of rearing, production schedule and efficient allocation of water resources considering biological and economic condition. The purpose of this article is to build the mathematical decision making model that finds the value of decision variable to maximize profit under the constraints. Stocking and harvesting decisions that are made by master production planning are affected by the price system, feed cost, labour cost, power cost and investment cost. To solve the proposed mathematical model, heuristic search algorithm is proposed. The model Input variables are (1) the fish price (2) the fish growth rate (3) critical standing corp (4) labour cost (5) power cost (6) feed coefficient (7) fixed cost. The model outputs are (1) number of rearing fish (2) sales price (3) efficient allocation of water pool.

• KSBB Journal
• /
• 제26권4호
• /
• pp.311-316
• /
• 2011

We investigated the optimal surface aeration rate during bioethanol production from the hydrolysate of seaweed Sargassum sagamianum using Pichia stipitis. It was observed that, when the working volume was 880 mL in 2.5-L lab-fermentor, the surface aeration rates of 30 to 100 mL/min were the optimal values for bioethanol production, in which this surface aeration rate corresponded to less than 0.05 (1/min) as the oxygen transfer rate coefficient ($k_La$). In addition, during repeated-batch operation was carried out, we examined whether those surface aeration rates were the optimal for bioethanol production. It was also observed that the surface aeration rates of 30 to 100 mL/min in the working volume of 880 mL were the optimal values in terms of the cumulative bioethanol producrion and bioethanol yield. On the basis of the oxygen transfer rate coefficient it is probable that those surface aeration rates will be applied to the large-scale bioethanol production from the hydrolysate of seaweed Sargassum sagamianum.

• 한국융합학회논문지
• /
• 제9권7호
• /
• pp.63-68
• /
• 2018

농업 인구의 감소와 노령화로 인하여 온실 재배 중심의 스마트 팜에 대한 연구가 활발하게 진행 중이나 채소와 같은 작물의 경우 노지 재배가 70%를 차지한다. 이에 노지 농작물 재배의 자동화, 무인화 및 지능화를 통해 생산성을 향상시키고 토양 오염을 방지할 필요가 있다. 본 논문은 사물인터넷을 이용한 노지 농작물 제배 시스템 구축 사례를 설명하고 노지작물 제배 시스템에서의 환경 변수를 정의하였다. 다양한 센서을 통해서 토양의 온도, 함수율, 전기전도도, 산성도를 측정하여 LoRa 통신 모듈을 이용하여 서버로 정보를 전달하고, 서버는 이 데이터를 바탕으로 시비량 및 관수량을 제어한다. 노지농작물 재배에 적합한 통신 방식인 LoRa 기술을 이용하여 넓은 노지를 관리하고 생산량 및 판매실적까지 관리하는 시스템을 개발하였다.

• 한국산림과학회지
• /
• 제74권1호
• /
• pp.82-87
• /
• 1986

대다수의 잣나무가 잣을 수확(收穫)하는 과정에서 수간(樹幹) 정단부(頂端部)의 인위적인 손상으로 말미암아 전형적인 잣나무 수형(樹型)을 잃게되는 점에 착안하여, 정상적으로 생육한 낙엽송과 비교하여 임본(林木) 제형질(諸形質)들의 관계를 조사 연구하였다. 동령급(同齡 級)의 두 수종(樹種)을 비교한 결과, 잣나무는 원단부(原端部)의 절단(切斷)으로 인하여 정상적인 수고생장(樹高生長)을 못하고 있음을 알 수 있으며, 또한 심하게 분간(分幹)되거나 굴곡된 수간(樹幹)은 이용재적(利用材積) 값을 낮추는 결과를 초래하여 본재생산(木材生産)의 측면에서는 바람직한 수형(樹型)을 갖지 못하고 있었다. 그러나 잣을 수확(收穫)할 수 있고 용재(用材)를 생산할 수 있는 잣나무의 특성을 감안하여, 조림투자(造林投資)에 대한 회수율(回收率)을 최대화하기 위한 잣나무 식재림(植栽材)에 대한 경영적(經營的) 대안(代案)을 제시하였다.

• 대한교통학회지
• /
• 제33권1호
• /
• pp.61-69
• /
• 2015

이 연구에서는 국내 총 화물물동량에 대한 5개 계량경제모형들의 예측정확도를 비교한다. 적용된 5개 모형은 통상최소자승모형, 부분조정모형, 축소된 자기회귀분포시차모형, 벡터자기회귀 모형, 시간변동계수모형이다. 모형의 추정과 예측은 1970-2011년 동안의 연간 국내 화물물동량 자료와 광공업생산지수를 이용하여 수행되었다. 5개 모형은 반복적인 예측방법을 이용하여 1년 후, 3년 후, 5년 후 예측성능이 비교되었다. 추가적으로 장래변동성의 크기에 따라 두 예측기간으로 나누어 예측정확도를 비교하였고, 결과적으로 시간변동계수모형은 변동을 갖는 예측기간에 대해서 가장 높은 정확도를, 반면에 벡터자기회귀 모형은 점진적인 변화를 갖는 예측기간에 대해서 다른 모형에 비해 우수한 성능을 보여주는 것으로 분석되었다.

• 유기물자원화
• /
• 제22권2호
• /
• pp.57-66
• /
• 2014

침출수 순환형 음식물류 폐기물 혐기성 소화 공법은 기존의 일상 혐기성 소화 공법에 비해 투입되는 유기물 부하량 대비 발생하는 메탄가스 수율이 높다는 장점이 있다. 본 연구는 분리 수거된 교내 기숙사 식당 음식물류 폐기물과 하수처리장 혐기성 소화조의 혐기성 미생물을 이용하여 신재생 에너지인 메탄가스를 더욱 효율적으로 얻기 위해 음식물류 폐기물/혐기성 슬러지 비를 달리하여 실험을 실시하였다. 음식물류 폐기물/혐기성 슬러지 비가 2:8이고 유기물 부하율이 9 gVS/L인 침출수 순환형 음식물류 혐기성 소화 반응조의 바이오 가스 발생이 가장 높았다. 또한 이 혐기성 반응조에서 발생하는 바이오가스 내부의 $H_2S$와 $NH_3$가 지속적으로 감소하였고 바이오 가스의 수율은 평균 $1.395m^3$ Biogas/kg VS added로 나타났다. 이에 비해 나머지 음식물류 폐기물/혐기성 슬러지 비가 3:7, 8:2인 실험의 반응조에서는 바이오 가스 발생이 멈추었다.

• 환경위생공학
• /
• 제10권1호
• /
• pp.35-44
• /
• 1995

The study was carried out to investigate on the response of environmental sanitation problems in action of the volume based waste charge system in Seoul The responses from the 346 persons who dwelled in Seoul was stimulatively answered, this system was considered as a successful on 70.5% of total answers, but little portion(29.4 % ) of those was unknown on the mean of this system. And we knew that this system was need to the communication and education through the press media about this one. After the action of the volume based waste system, the volume of refuse discharged in a day was decreased 30 ∼40% than before. In the problems of environmental sanitation after this system, the number of sanitary insect( cockroach etc ) and rat was decreased, also the production of orders and dust caused by refuse was decreased in comparison with those before. This results were considered that the Separate Collection should be perfectly performed. In response, the regular envelope of refuse was serious problems, the improvement for this one was demanded. The kind of difficult refuse treated was waste rubbers> electric products > furniture> foodstuffs> bottles, cans> papers, pulps etc, and the next proposal for this system should be prepared. Conclusively, the volume based waste charge system should be remarkable system In terms of resources recycling as well as wastes reduction. Above all in order to conform this system the separate collection system should be systematically performed, the next improvable proposal of the detailed methods in this system should be prepared.

• 환경위생공학
• /
• 제13권1호
• /
• pp.82-90
• /
• 1998

The study was carried out to investigate on the response of environmental sanitation problems in action of the volume based waste charge system in Seoul. The responses from the 396 persons who dwelled in Seoul was stimulatively answered, this system was considered as a successful one 69.6% of total answers, but little portion (21.2%) of those was unknown on the mean of this system. And we knew that this system was need to the communication and education through the press media about this one. After the action of the volume based waste charge system, the volume of refuse discharged in a day was decreased 30-50% than before. In the problems of environmental sanitation after this system, the number of sanitary insect(cockroach etc) and rat was decreased, also the production of order and dust caused by refuse was decreased in comparison with those before. This results were considered that the Separate Collection should be perfectly performed. In response, the regular envelope of refuge was serious problems, the improvement for this one was demanded, The kind of difficult refuse treated was waste foodstuffs> electric products> rubbers> furniture> bottles, cans>papers, pulps etc. and the next proposal for this system should be prepared. Conclusively, the volume based waste charge system should be remarkable system in terms of resources recycling as well as wastes reduction. Above all in order to conform this system the separate collection system should be systematically performed, the next improvable proposal of the detailed methods in this system should be prepared.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2020년도 추계국제학술대회
• /
• pp.59-59
• /
• 2020

Salix gracilistyla has a characteristic of fast growth especially in the river side or infertile soil, showing a lot of lateral branches and a strong root system among the Salix. spp. On the basis of results observed, we provide several growth characteristics of S. gracilistyla among some selected provenances. In two-year results, root collar diameter ranged from 33.5 mm to 56.7 mm. Taeback showed the lowest value, and Jeongseon and Hoengseong were higher than the other areas in the traits above. Height growth was the lowest in Samcheok and the highest in Wonju. To examine growth and development of lateral branches is important because S. gracilistyla has a lot of lateral branches which account for high biomass production. Length of lateral branch showed high variation, in which the highest number was observed in Yeongwol and the lowest in Samcheok. Many lateral branches were shown in Wonju. Preliminary study on biomass resources evaluation, we analyzed correlation between volume and length, and volume and root diameter. High correlation was observed between root diameter and plant volume. And we compared the observed volume with the caculated volume by regression formula. To evaluate Salix species as biomass resources, it is needed to survey growth characteristics continuously and adopt selection of individuals or families of high biomass and caloric values by reliable data. In addition, Salix spp. can be also applicable to selection breeding regime because of feasible propagation and fast growth.

• 아시안잔디학회지
• /
• 제13권1호
• /
• pp.29-36
• /
• 1999

This study was conducted to make the utmost use of the good traits and to improve the poor traits of zoysiagrass through the production technology for mixed lines sod in addition to breeding. Mixed lines sod was produced by mixing broad or middle leaf line with narrow leaf line by volume, a ratio of 1 to 2. The mixed lines sod of zoysiagrass was superior to the single ling sod, which is used commonly, for the establishment rate, coverage rate, shoot density, texture, leaf color, dormancy period cnd color, and visual quality.