• 한국패류학회지
• /
• 제27권4호
• /
• pp.331-336
• /
• 2011

2011년 4월 20일부터 7월 15일까지 전복배합사료와 건다시마를 먹이원으로 한 북방전복과 해삼의 실내 복합사육에서 생존율과 성장에 어떠한 영향을 받는지 관찰하였다. 실험에 사용된 북방전복의 크기는 각장 $28.54{\pm}1.23mm$, 전중량 $2.92{\pm}0.26g$ 이었고, 해삼은 습중량 $3.0{\pm}0.2g$ 이었다. 먹이는 전복배합사료 실험구, 건다시마 실험구 및 전복배합사료와 건다시마 혼합 실험구로 설정하였다. 북방전복과 해삼의 생존율은 모든 실험구에서 각각 97.0%, 87.0% 이상을 보였다. 북방전복의 생존율은 건다시마 실험구에서 가장 높은 반면 해삼은 가장 낮았지만 유의적인 차이는 보이지 않았다. 성장은 북방전복의 경우 전복배합사료 실험구에서, 해삼의 경우 전복배합사료와 건다시마를 동시에 공급한 실험구에서 가장 빨랐다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
• /
• pp.31-36
• /
• 1992

This paper, an experimental study on the effect of mixed sand used sea and river as fine aggregate of concrete, is connected with the properties of fresh and hardended concrete and steel corrosion to investigate workability and engineering properties and general steel bar's corrosion of concrete used mixed sand. After analyzing positively fresh and hardenend concrete and ratio of the corrosion area affected by the autoclave cycle, the purpose of this paper is to provide an experimental data developing concrete used mixed sand.

• 과학교육연구지
• /
• 제38권1호
• /
• pp.160-167
• /
• 2014

이 연구의 목적은 해륙풍에 대해 초등학생들이 어떻게 인지하고 있는지 알아보는 것이다. 연구를 위해 J시 소재 초등학생 159명을 표집하였다. 연구결과 초등학생들 중 해륙풍과 바람이 부는 이유에 대해 바르게 이해하고 있는 학생은 총 159명 중 45명(29.3%)에 불과했다. 대부분의 학생들은 실험결과를 가지고 그대로 해륙풍의 방향을 설명하였다. 즉 학생들은 실험결과를 가지고 해륙풍을 추리하지 않고 있었다. 학생들은 추론 과정을 거치지 않고 실험결과를 그대로 해륙풍의 방향으로 결론지었다. 이러한 결과는 해륙풍에 관한 바른 이해를 위해 새로운 실험 기구의 개발과 실험과 관련된 학습 과정에서 추리 과정을 강조하여 가르쳐야 한다는 점을 시사해주고 있다.

• 한국해양공학회지
• /
• 제15권4호
• /
• pp.120-125
• /
• 2001

This paper describes the effect of fly ash replacement on the setting time of antiwashout underwater concrete, where cement was replaced by 0% to 50%. Experimental work was performed on the condition of sea water and in air to find out the characteristics of setting time between the concretes that were cast in air and cast in 15$^{\circ}C$ of sea water. The experimental results show that the setting time of underwater concrete with 50% replacement was delayed about 10 hours than normal concrete. And it can be concluded that, at the case of underseawater concrete addicted with fly ash, the delayed final setting times are shown as the function Tf=0.069F+7.69, where Tf is the delayed final setting time and F is quantity of fly ash, respectively. These results confirm that the setting time underseawater concrete could be prolonged.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1996년도 The Korean Institute of Navigation 1996년도 춘계학술발표회 논문집
• /
• pp.5-20
• /
• 1996

It is important to investigate the hull response of a fishing vessel in waves to ensure the safety of it and to keep excellent sea-keeping qualities. For this purpose we measured the response of fishing vessels in waves using real sea experimental measuring system, We analyze the experimental data by statistical method and spectral analysis to get the characteristics of the response of vessels which have different tonnage. In this real sea experiment we use three stern trawlers which are the training ship in university. We know that the distribution of experimental response have Gauss distribution and Rayleigh distribution and smaller vessels have larger response.

• 한국항해학회지
• /
• 제20권3호
• /
• pp.31-42
• /
• 1996

It is important to investigate the hull response of a fishing vessel in waves to ensure the safety of it and to keep excellent sea-keeping qualities. For this purpose, we measured the response of fishing vessels in waves using real sea experimental measuring system. We analyze the experimental data by statistical method and spectral analysis to get the characteristics of the response of vessels which have different tonnage. In this real sea experiment, we use three stern trawlers which are the training ship in university. We know that the distribution of experimental response have Gauss distribution and Rayleigh distribution and smaller vessels have larger response.

• Fisheries and Aquatic Sciences
• /
• 제20권10호
• /
• pp.24.1-24.8
• /
• 2017

The experiment was conducted to investigate the effects of different algae in diet on growth, survival, and interleukin-10 productions of sea cucumber. At first, a 9-week feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed one of the six experimental diets containing ST (Sargassum thunbergii), UL (Ulva lactuca), UP (Undaria pinnatifida), LJ (Laminaria japonica), SS (Schizochytrium sp.), and NO (Nannochloropsis oculata) in a recirculating aquaculture system. The result showed that survival was not significantly different among the dietary treatments, and the specific growth rate (SGR) of sea cucumber fed the UL diet ($1.58%d^{-1}$) was significantly higher than that of sea cucumber fed the other diets (P < 0.05), except for the LJ and NO diets. Secondly, interleukin (IL)-10 gene expression was determined where mice splenocytes were stimulated with $10{\mu}g\;ml^{-1}$ of sea cucumber extracts for 2 h. The result showed that IL-10 gene expression levels were significantly increased in UL, LJ, and NO diets fed sea cucumber extracts compared to other experimental diets. The results suggest that dietary inclusion with Ulva lactuca, Laminaria japonica, and Nannochloropsis oculata algae may improve the growth of juvenile sea cucumber and could upregulate IL-10 gene expression in mice splenocytes. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture.

• Journal of Nutrition and Health
• /
• 제30권5호
• /
• pp.499-505
• /
• 1997

This study was conducted to investigate the effect of various types of calcium sources on calcium metabolism. Sprague-Dawley male rate weighing approximately 82g were divided into 6 groups and fed experimental diets containing about 0.2% calcium for 4 weeks. Perilla leaves, dried sea mustard, mulberry leaves, loach, skim milk powder, and CaCO3 were used as calcium sources for this study. Food intake of experimental groups showed no significant difference from that of control group, but food efficiency ratio were higher in group fed loach as a calcium source. Apparent calcium absorption from perilla leaves, and skim milk powder groups as good as that in CaCO group. Femur length showed no significant difference among exjerimental groups with different calcium sources. The breaking force of bone was higher in loach and dried sea mustard groups. Weight, ash weight, and calcium content of the femur were higher in the loach diet group than in the others. Thus, calcium from not only skim milk powder but also perilla leaves, dried sea mustard, mulberry leaves, and loach appears readily available and all of these can be recommended as calcium sources.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.951-956
• /
• 2005

Since a snake achieves various movements just by a slender body, the mechanism of it is very amazing Many researches have been focusing on a snake like robot and have done for it on the ground. However the meander motion of the snake not only can be done by ground creatures, but also can be done by a water creature such as a sea snake or an eel. Therefore, the purpose of our research is to develop an autonomous underwater robot like the sea snake. As an approach to this goal, we develop an experimental sea snake-like-robot for examining basic characteristics, including propulsion, a turning and other performance. Our developed robot is composed of the head and 4 bodies. Each body equips one servomotor, which is operated with pulse signal. In the head unit, 1- chip-microcomputer, which generates the servomotor control signal for realizing a snake motion and the battery, is equipped. Our robot is covered with a rubber film for the waterproof. Using our developed robot, characteristics of the snake-like-robot moved in water are examined.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
• /
• pp.76-82
• /
• 1997

Recently as the development of a large-scale ocean structure or ocean is in progress, the importance of underwater concrete construction came to the fore. However, a problem with this underwater concrete construction is the segregation of cement and aggregate occurs when concrete is poured into the underwater. However, recently as an adhesiveness of the constituents of fresh concrete is increased even in our country, antiwashout concrete admixture were developed. The antiwashout concrete admixture can reduce the segregation significantly. Although this antiwashout underwater concrete is superior to the traditional underwater concrete in terms of durability, watertightness, stability, etc. But it is still unsatisfied due to the lack of criterion or construction experiences. Furthermore, because of an insufficiency of natural aggregate, the development of replacing aggregate came to be necessary. Accordingly, the purpose of this study is to investigate the feasibility of sea sand as a replacing aggregate and the characteristic change of antiwashout underwater concrete using river sand, sea sand, and blended sand (river sand:sea sand=3:7) through experimental researches.