간행물
수산해양기술연구 KCI 등재 Journal of the Korean Society of Fisheries and Ocean Technology 韓國漁業技術學會誌
- 발행기관 한국수산해양기술학회(구 한국어업기술학회)
- 자료유형 학술지
- 간기 계간
- ISSN 2671-9940 (Print)2671-9924 (Online)
- 수록기간 1965 ~ 2024
- 주제분류 농수해양 > 수산학 농수해양 분류의 다른 간행물
- 십진분류KDC 529DDC 639
권호리스트/논문검색
권호
28권 1호 (1992년 3월) 12건
1.
1992.03
구독 인증기관 무료, 개인회원 유료
The author has examined the response of sting fish, Sebastes inermis and black porgy, Acanthopagrus schlegelii to the attraction lamps(1 W) line in an experimental water tank(550 L× 58 W × 73H cm). Attraction lamp was set up at intervals of 55 cm for each section. The frequency rate was investigated at the illuminated section in accordance with the intervals of lighting on and putting out that was 1, 3 and 5 minutes under two conditions of light stimulus. The results are as follows: 1. Frequency rate at the last section when each of the attraction lamps was gradually switched on and off: (1) Sting fish was 27.2 % in case of 3 minutes interval, and 17.4 % in 1 minutes interval, and 15.8 % in 5 minutes interval. (2) Black porgy was 28.5 % in case of 5 minutes interval, and 25.8 % in 3 minutes interval, and 12.0 % in 1 minutes interval. 2. Distribution of fish at the illuminated section when each of the attraction lamps was gradually switched off after they were switched on all at once: (1) Sting fish was much gathered in the section adjacent to the extinguished section under the condition of 1 and 3 minutes interval, and not regular trend under 5 minutes interval. (2) Black porgy was much gathered last section under the condition of 1 and 3 minutes interval, and almost evenly distributed under 5 minutes interval. 3. Each of the attraction lamps was gradually switched off after they were switched on all at once, and only the last one was on: (1) The frequency rate of Sting fish was 27.2 % in case of 5 minutes interval, and 16.0 % in 1 minute interval, and 8.0 % in 3 minutes interval. (2) The frequency rate of Black porgy was 10.7 % in case of 1 minute interval, and 8.9 % in 3 minutes interval, and 0.8 % in 5 minutes interval.
4,000원
2.
1992.03
구독 인증기관 무료, 개인회원 유료
The new course distances of a ship are considered to be the indices to indicate directly her abilities of course altercation. Generally, they have long been calculated by using the maneuvering indices obtained from her Z test. However, at sea actually the maneuvering indices can not sometimes be obtained according to ship's condition or circumstances and the new course distances can not be calculated. To find out other method to calculate the new course distances, in this paper the author analyzed them from a viewpoint of ship motion, and worked out a numerical formula to calculate them easily, using the data of ship's heading test. In order to check whether the presented method is applicable to actual ships or not, the experiment by them were also performed. The results obtained are summarized as follow: 1. The mean difference of the distance between two new course distances by the heading test and the maneuvering indices of the experimental ship was about 0.98% values of the ones by the maneuvering indices, when her heading were 10。, 20。 and 30。, using the rudder angle of 15。. These new course distances were therefore found to be almost same in values of the distance. 2. The mean difference of the distance between two new course distances by the heading test and the observation of experimental ship was about 1.16% values of the ones by the observation, when her headings were 10。, 20。 and 30。, using the rudder angle of 15。. These new course distances were therefore found to be almost same in values of the distance. 3. It is confirmed that the new course distances can be calculated easily by using the method of ship's simple heading test, without the observation or using the maneuvering indices. 4. It is considered to be helpful for the safety of shiphanding to draw curves of new course distances by ship's heading test and utilize them at sea.
4,200원
3.
1992.03
구독 인증기관 무료, 개인회원 유료
Generally a navigator evaluated the maneuverability of his ship by the scale of turning circle which was described only by the largest rudder angle of the port and starboard sides. But to have the sufficient knowledge of his ship's maneuvering characteristics he should consider the data about the new course keeping test, the spiral test, and the turning circle tests in accordance with the rudder angles together. In this paper the author performed the above tests to study the maneuverability of the stern trawler M.S. Pusan 404 which is a training ship of the National Fisheries University of Pusan. The obtained results are summarized as follows: 1. When the rudder angles being 5。, 10。, 20。, 30。, 35。 the advances of the starboard side turning circles were 12.8, 8.2, 4.8, 2.9, 2.7 times as large as the length of the ship, and of the port side turning circles were 13.3, 8.7, 5.4, 3.5, 2.9, time as large as the large as it. Under the same conditions the tactical diameters were 15.1, 9.7, 5.2, 3.1, 2.8 times as large as the length of the ship, for starboard side, and 17.2, 12.4, 6.4, 3.7, 3.2 times as large as it for port side. 2. As the rudder angle being increased the ratio of the advance to the tactical diameter was nearly 1 and her obeying ability was better than that of the small angle. 3. The mean values of the rates of speed reduction during the steady turning motion were 0.96, 0.92, 0.82, 0.71, 0.65 in accordance with the rudder angles. 4. The relative formulas between the distance to the new course y and the altering course x were as follows: When rudder angles being 10。, 20。, 30。, y=52.2222+1.6133x, y=48.750+0.9383x, y=39.250+0.655x respectively. 5. There was little difference of the distance to the new course between rudder angle 20。and 30。, and so it is desirable for a navigator to a navigator to use the small rudder angles unless sudden emergencies. 6. Though her rudder angle being small her course stability was good according to the spiral tests.
4,000원
4.
1992.03
구독 인증기관 무료, 개인회원 유료
The paper presents a digital speed control approach of induction motor systems by using a digital redesign method and adopting a well known 2nd order model as the system model equation. The basic concept using the modeling equation is induced from the control theory stand point such that we can describe usually the motor system connected by inverter, generator and load etc. just as a mechanical system to be controlled. The concept does not demand us the complicated vector-based modeling equation adopted in the traditional methods for the speed control of induction motor. The effectiveness of the servo control system composed by the above mentioned design concept is illustrated by the experimental results in the presence of step reference change and generator load variation. It is observed from the experimental results that the steady state error of the experimental set up becomes zero after some regulation time and the induction motor system is robust in spite of reference signal change and load variation of generator.
4,300원
5.
1992.03
구독 인증기관 무료, 개인회원 유료
Analog PID controllers have been designed to make good use of position control in industries. Recently, the importance of digital position control is emphasized for the requirements of controller which are not only to control the objects but to include various aspects such as easiness of design and implementation, simple exchange of control program and convenient communications of data between various controllers and a host computer. This study proposes a combined control method which is mixed the vaiable structure control (VSC) with the PI control for minimum time position control of DC servo motor by microcomputer. The results of test by this method show offset-free and minimum time optimal position control which is not affected by the disturbance and the system parameter variations. The validity of the proposed method comparing with the conventional PID control is proved by the response experiments.
4,000원
6.
1992.03
구독 인증기관 무료, 개인회원 유료
In this paper, combustion characteristics and engine performance varying with blending rate of fish oil using five test fuels, e.g.pure diesel oil and four types of sardine-oil-blended diesel oils, their blending rates by weight being 20%, 40%, 60% and 80% respectively, and operating condition of engine, were investigated experimentally both in the constant volume combustion bomb and in the engine. The results are summarized as follows: 1) In the bomb, the influence of temperature on ignition delay of sardine-oil-blended diesel oils was larger than that of pure diesel oil, and it tended to increase as the blending rate of fish oil increase sardine-oil-blended diesel oils. As far as the influence of pressure on ignition delay concerns, there was no significant difference with all the test fuels. 2) In the engine, the ignition delay of fish-oil- blended diesel oils was longer than that of pure diesel oil, and it tended to increase as the blending rate increases. In the bomb, the ignition delay in high temperature showed no significant difference between with pure diesel oil and with fish-oil-blended diesel oils, and it was especially short with 60% fish-oil-blended diesel oil. In low temperature, however, the delay became longer as the blending rate increase. 3) The combustion duration was shorter with fish-oil-blended diesel oils than with pure diesel oil and it became a little shorter as the blending rate increases. 4) The rate of fuel consumption showed no significant difference between with fish-oil-blended diesel oils and with prue diesel oil, although calorific value of fish oil was lower than that of diesel oil. 5) Smoke density in exhaust gas was lower with fish-oil-blended diesel oils than with pure diesel oil and the higher the blending rate was, the lower the smoke density became
4,000원
7.
1992.03
구독 인증기관 무료, 개인회원 유료
In this study, cathodic protection experiment was carried out by Al-alloy sacrificial anode in marine environments which have specific resistance(σ) if 25~7000Ω.cm and investigated protection potential, current density and loss rate of Al-alloy sacrificial anode. The main results resistance(σ) of 400Ω.cm, the cathodic protection potential appears high about-720 mV(SCE). But below specific resistance(σ) of 300Ω.cm, the cathodic protection potential appears low about-770 mV(SCE) and simultaneously, cathode is protected sufficiently. 2) The loss rate of Al-Alloy sacrificial anode became large with decreasing specific resistance and increasing the ratio(A sub(c)/A sub(a) of bared surface area of anode and cathode. 3) The loss rate of Al-alloy sacrificial anode(w) to the mean current density of anode(i) is as follows. w=ai+b (a, b : experimental constants)
4,000원
8.
1992.03
구독 인증기관 무료, 개인회원 유료
In this study, corrosion fatigue test of SAPH45 steel was performed by the use of plane bending fatigue tester in marine environment and investigated fracture surface growth behavior of base metal and heat affected zone corrosion fatigue. The main results obtained are as follows: 1) Fracture surface growth of heat affected zone (HAZ) is delayed more than that of base matel (BM), and they tend to faster in seawater than in air. 2) Corrosion sensitivity to corrosion fatigue life of HAZ is more susceptible than that of BM. 3)In the case of the corner crack by corrosion fatigue, the correlation between the propagation rate of fracture surface area(dA/dN) and stress intensity factor range(ΔK) for SAPH45 are applied to Paris rule as follows: dA/dN=C(ΔK) super(m) where m is the slope of the correlation, and is about 6.60-6.95 in air and about 6.33-6.41 in seawater respectively.
4,000원
9.
1992.03
구독 인증기관 무료, 개인회원 유료
Zr-4 used for a cladding and an end plug of reactor component has creep deformation under operation at high temperature. Creep is regarded as the time dependent deformation of a material under constant applied stress. Although the major source of the deformation of zirconium component in water-cooled reactors is irradiation creep, the thermal creep may give a rise to significant deformation in reactor component especially at relatively high temperatures and at various constant stresses, and therefore it must be predicted accurately. Stress relaxation is the time dependent change of stress at constant strain and it is a process related intimately to creep. In this paper, the creep behavior and stress relaxation of Zr-4 is examined at the temperature of 500℃ that is 40% of the absolute melting temperature of Zr-4 under the stress below yield stress and under the various constant strains. The results obtained are summarized as follows: 1) With an increase of stress, the steady state creep rate increases and the creep rupture time decreases. 2) The steady state creep rate ε(%/s) for the stress Σsub(c) (kgf/mm super(2)) of Zr-4 increases outstandingly. All the empirical equations computed for Zr-4 increases outstandingly. All the empirical equations computed for Zr-4 are in accord with Norton's model equation(ε=KΣ sub(c) super (n)). The constants of materials computed are as follows: K=3.9881×10 super(-5), n=1.9608 3) The rupture time T sub(r) (hr) decreases linearly with the increase of stress on the log-log scaled graph. The empirical equations computed for Zr-4 are in accord with Bailey's model equation (T sub(r)=K sub(1)Σsub(c) super(m)). The constants of materials computed are as follows: K sub(1)=1.2875×10 super(16), m=-3.467 4) It seems clear that the strain could be quantitatively dependent on the high temperature creep properties such as creep stress, rupture time, steady state creep rate and total creep rate. It is found that these relationships are linear on the log-log graph. 5) In stress relaxation test, as the critical constant strain that can be allowed to the specimen is larger, stress relaxation becomes more rapid, and as the constant strain is smaller, the stress relaxation becomes slower.
4,000원
10.
1992.03
구독 인증기관 무료, 개인회원 유료
This is analyzed using the finite element method which is appling excellent isoparametric curve element in the aspect of large usages of dynamic responses in which is regarding geometric and material nonlinear of a large scale shell structure of an airplane, a submarine, a ship, and an ocean structure. The solution of dynamic equations is got by direct integration method using time-stepping procedure and regarding Central Difference Method of the both solutions. But because formal matrix factorization is not necessary in each time step and it does not take less time to compute relatively, this method must be regarded very few time steps on the condition. Axisymmatric shell problems are inspected using 8 node Isoparametric element in this paper. Partial axisymmatric spherical shell is used as a model to analyze axisymmatric nonlinear dynamic behavior regarding. Total Lagrangian formulation in geometric nonlinear behavior and elastio-viscoplastic in material nonlinear behavior.
4,600원
11.
1992.03
구독 인증기관 무료, 개인회원 유료
The hydrodynamic interaction characteristics between multiple floating bodies of semisubmersible type are examined for presenting the basic data for the design of huge offshore structures supported by a large number of the floating bodies in waves. The numerical approach is based on combination of a three-dimensional source distribution method and interaction theory which is exact within the context of linear potential theory. The method is applicable to an arbitrary number of three-dimensional bodies having any individual body geometries and geometrical arrangement with the restriction that the circumscribed, bottom-mounted, imaginary vertical cylinder for each body does not contain any part of the other body. The validity of this procedure was verified by comparing with numerical results obtained in the literature.
4,200원
12.
1992.03
구독 인증기관 무료, 개인회원 유료
필자는 어업 개발도상국에 대한 정부의 대외기술공여 사업의 일환으로 1991년 12월 16일 부터1992년1월15일까지 중동아시아의UAE농수산부로로서, 해양자원 연구센타의 안내를 받아 자국의 주요어항을 순회하면서 어업실태를 파앙ㄱ하고 어민과 공무원을 대상으로 현장지도 교육을 실시하는 한편 연구센타의 연구원들과 토론을 통하여 이 나라의 어업이 나아가야할 방향에 대하여 집중적으로 논의 하였다. 본서는 그간에 수집한 여러자료와 함께UEA어업의 개선방향에 대한 지문내용을 간추린 것이다.
4,000원
