• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.109.5-109
• /
• 2002

Autonomous underwater vehicles (AUVs) are unmanned underwater vessels to investigate sea environments, oceanography and deep-sea resources autonomously. Docking systems are required to increase the capability of the AUVs to recharge the batteries and to transmit data in real time in underwater. This paper presents a visual servo control system for an AUV to dock into an underwater station with a camera. To make the visual servo control system , this paper derives an optical flow model of a camera mounted on an AUV, where a CCD camera is installed at the nose center of the AUV to monitor the docking condition. This paper combines the optical flow equation of the camera with the AUV's equation o...

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.5
• /
• pp.460-470
• /
• 2011

This paper presents a dynamic workspace control method of underwater manipulator considering a floating ROV (Remotely Operated vehicle) motion caused by sea wave. This method is necessary for the underwater work required linear motion control of a manipulator's end-effector mounted on a floating ROV in undersea. In the proposed method, the motion of ROV is modeled as nonlinear first-order differential equation excluded dynamic elements. For online manipulator control achievement, we develop the position tracking method based on sensor data and EKF (Extended Kalman Filter) and the input velocity compensation method. The dynamic workspace control method is established by applying these methods to differential inverse kinematics solution. For verification of the proposed method, experimental data based test of ROV position tracking and simulation of the proposed control method are performed, which is based on the specification of the KORDI deep-sea ROV Hemire.

• The Journal of Korea Robotics Society
• /
• v.15 no.2
• /
• pp.139-146
• /
• 2020

In this paper, the slope of the footplate is adjusted to compensate for the centrifugal force with a series elastic actuator (SEA) attached to the Segway's body to improve the cornering characteristics during turning. To ensure Segway's driving safety in the curvature motion, it is necessary to compensate for the centripetal force by tilting the footplate to generate inward force from gravity. When the footplate is tilted under the control of SEA, the vertical load on both wheels has been changed accordingly. The frictional force of the wheel has been changed by the change of the vertical force, which requires adjustment of driving torque to keep the curvature trajectory. That is, the driving torque has been controlled to keep the curvature trajectory considering the frictional force caused by the turning motion. Four SEAs are attached to the footplate to control the slope of the footplate and the real curvature motion has been demonstrated to verify the effects of SEAs in the high- speed curvature motion.

• Fisheries and Aquatic Sciences
• /
• v.16 no.2
• /
• pp.93-99
• /
• 2013

In 2009, a systemic megalocytivirus infection associated with high mortality was detected for the first time in cultured starry flounder Platichthys stellatus in Korea. Diseased starry flounder had pale bodies and gill coloring and enlarged spleens. Histopathological examinations revealed basophilic enlarged cells in various organs of diseased starry flounder. Polymerase chain reaction (PCR) was performed on tissue samples using three published primer sets developed for the red sea bream iridovirus. PCR products were detected for all primer sets, except 1-F/1-R, which are registered by the World Organization for Animal Health (OIE). The part of the gene corresponding to the full open reading frame encoding the viral major capsid protein (MCP) was amplified by PCR. PCR products of approximately 1,581 bp were cloned, and the nucleotide sequences were analyzed phylogenetically. The MCP gene of the starry flounder iridovirus, designated SFIV0909, was identical to that of the turbot reddish body iridovirus (AB166788).

• The Korean Journal of Physiology
• /
• v.1 no.2
• /
• pp.199-213
• /
• 1967

Circulatory and respiratory activities were observed in men exposed to the environment of engine room of a cruising Republic of Korea Navy ship and compared to the control values obtained in an ordinary laboratory room on land. The environment of an engine room of cruising navy ship was presumed to be a multiple stress acting on men. The environment of the engine room included high temperature $(35-42^{\circ}C)$, low relative humidity (20-38% saturation), vibration (about 7 cycles per second), rolling and pitching of ship and noises. Sixteen men were divided into two groups consisted of each 8 subjects. Subjects of sea duty group had experience of continuous on board duty averaging 3.5 years. Men of land duty group had no experience of on board activity. On land observations were made on one day prior to the boarding and leaving the port and four days after landing. In between observations in the engine room were made on the first, 5 th, 9 th, 12 th, and 14 th day of on board activity. The whole experimental period lasted for 20 days. Measurements on circulatory and respiratory parameters were at standing resting state (after 30 minutes standing in the case of on land study and 15 minutes in engine room study) and within one minute after cessation of on the spot running of which rhythm was 30/min. and lasted for 5 minutes. Oxygen consumption and pulmonary function test were done in the period of two minutes from the 3rd to 5th minutes of running. The following results were obtained. 1. Body temperature showed no change regardless of group difference or on land or on board measurements. 2. Pulse rate increased markedly after boarding the ship id both groups. Pulse rate increased from the first day on board at rest and after exercise as compared to the on land control value. This increase in pulse rate was more marked after exercise. Sea duty group showed less increase in pulse rate at rest than the land duty group. Standing and resting pulse rate of sea duty group on lam was 81 and increased to 87 at the 5th day on board and remained smaller than the land duty group throughout the period on board. Control standing and resting pulse rate of land duty group on land was 76 and reached 89 at the 9th day on board and thereafter decreased a little. Pulse rate of land duty group at rest on board remained greater than that of sea duty group throughout the period on board. 3. Systolic blood pressure of sea duty group increased after boarding the ship and remained higher than the control value on land. In the land duty group, however, systolic blood pressure decreased during the period on board the ship. Diastolic blood pressure decreased in both groups. 4. Resting breathing rate of land duty group increased and remained higher than the control value on land. In sea duty group, however, resting breathing rate showed a transient increase on the 1st day on board and decreased thereafter to the control value on land and kept the same level throughout the period of cruise. Absolute value of breathing rate in the sea duty group was greater than the land duty group both at rest and after exercise. 5. There was a lowering of breathing efficiency in both groups. Thus, increases in tidal volume and minute ventilation volume and decreases in maximum breathing capacity, vital capacity, capacity ratio and air velocity Index were observed after boarding the ship. An increase in ventilation equivalent was also observed in both groups. The lowering of breathing efficiency was more marked in the land duty group than the sea duty group. 6. Energy expediture increased in both groups during their stay on the ship and was more marked in the sea duty group. 7, Lactate concentration in venous blood at rest and after exercise increased after boarding the ship and no group difference was observed.

• Food Science and Preservation
• /
• v.12 no.3
• /
• pp.241-246
• /
• 2005

This study showed the optimum conditions for producing rice extrudate added with the sea tangle powder, and presented the effects of moisture content, barrel temperature and the amount of sea tangle powder. From the results, the more the amount of sea tangle powder was added, the less the water absorption ratio was showed, while the more the texture became smooth, the more the expansion ratio increased. From the sensory evaluation, the best preference was obtained when the moisture content was $18\%$, and the barrel temperature was at $100^{\circ}C$. Between control and $10\%$ sea tangle, there was no significant difference in all observed parameters. But if more than $20\%$ sea tangle was added, low sensory evaluation scores were obtained due to the peculiar smell from sea tangle. From these results, addition of sea tangle below $10\%$(w/w) did not affect the quality of products.

• Maritime Security
• /
• v.6 no.1
• /
• pp.1-35
• /
• 2023

The purpose of this study is to present the direction of development of our navy's response strategy through analysis at the ends, ways, and means level of the Chinese navy's offensive strategy for the West Sea. As a result of the analysis, at the ends level, the Chinese Navy's offensive strategy for the West Sea strategy is being linked to a grand strategy to protect maritime rights and achieve maritime power between the U.S. and China competition, at the ways level, the Chinese Navy is expected to create a foundation for the international community to recognize the West Sea as China's inland sea through "routine entry" and "exercise authority", and in case of emergency, it will try to secure sea control in the West Sea in a short period of time by blocking Korea's maritime transportation route based on the overwhelming preemptive attack capability of aircraft carriers. At the means level, it is accelerating the construction of aircraft carrier warfare units and improving its ability to engage long-range missiles. As a direction of development of the Korean Navy's response strategy in response to this, first, Establishment and Development of National Maritime Security Strategy in conjunction with the Korean Indo-Pacific Strategy. Second, it proposes the development of the concept of effective security operations for the east sea area of the West Sea intermediate line, and third, the development of the concept of combat performance and capacity building to strengthen survival and lethality.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.10
• /
• pp.964-969
• /
• 2012

Robot hands capable of grasping or handling various objects are important for service robots to effectively aid humans. In particular, controlling a contact force and providing a compliant motion are essential when the hand is in contact with objects. Many dexterous robot hands equipped with force/torque sensors have been developed to perform force control, but they suffer from the complexity of control and high cost. In this paper, a low-cost robot hand based on SEA (Series Elastic Actuator), which is composed of compression spring, stretch sensor, and wire, is proposed. The grasping force can be estimated by measuring the compression length of spring, which would allow the hand to perform force control. A series of experimentations are carried out to verify the performance of force control of the proposed robot hand, and it is shown that it can successfully control the contact force without any additional force/torque sensors.

• Journal of Environmental Science International
• /
• v.30 no.6
• /
• pp.465-474
• /
• 2021

This research investigated the characteristics of fine particle concentration and ionic elements of PM_2.5 during sea breeze occurrences during summertime in Busan. The PM₁₀ and PM_2.5 concentrations of summertime sea breeze occurrence days in Busan were 46.5 ㎍/m³ and 34.9 ㎍/m³, respectively. The PM₁₀ and PM_2.5 concentrations of summertime non-sea breeze occurrence days in Busan were 25.3 ㎍/m³ and 14.3 ㎍/m³, respectively. The PM_2.5/PM₁₀ ratios of sea breeze occurrence days and non-sea breeze occurrence days were 0.74 and 0.55, respectively. The SO₄^2-, NH₄⁺, and NO₃^- concentrations in PM_2.5 of sea breeze occurrence days were 9.20 ㎍/m³, 4.26 ㎍/m³, and 3.18 ㎍/m³ respectively. The sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) of sea breeze occurrence days were 0.33 and 0.05, respectively. These results indicated that understanding the fine particle concentration and ionic elements of PM_2.5 during sea breeze summertime conditions can provide insights useful for establishing a control strategy of urban air quality.

• Journal of Life Science
• /
• v.9 no.4
• /
• pp.430-438
• /
• 1999

This study was designed to investigate the effects of sea tangle (Laminaria japonica) extract and fucoidan components on chronic degenerative diseases. Sprague-Dawley(SD) male rats (210$\pm$5g) were fed experimental diets: Dasi-Ex group: dasima extract powder of 4.0% added to control diet; Fuco-I, II and III groups: fucoidan powder of 1, 2 and 3% added to Dasi-Ex group for 45 days. Triglyceride (TG) levels in serum were significantly lower (10~15%) in Fuco-I, II and III groups compared with control group. Total cholesterol levels were significantly decreased (7~10% and 15~ 35%) in brain mitochondria and microsomes of Fuco-II and III group compared with control group. LDL-cholesterol levels were remarkably decreased (20~30%) in Dasi-Ex and Fuco-I, II, III groups, but HDL-cholesterol levels were significantly increased (10~12%) in Fuco-II and III groups only compared with control group. The ratios of HDL/total cholesterol resulted in a marked increase (3 5~55%) in Dasi-Ex and Fuco-I, II, III groups, but atherogenic indices were remakably decreased (40~50%) in Dasi-Ex and Fuco-I, II, III groups compared with control group. Membrane fluidities were remarkably increased (45~70% and 38~42%, respectively) in brain mitochondria and microsomes of Fuco-II and III groups compared with control group. Administrations of fucoidan added to dasima effectively decreased TG, total and LDL-cholesterol, and atherogenic index, while also effectively increased HDL-cholesterol, HDL/total cholesterol ratio, and membrane fluidity, suggesting chronic degenerative diseases were very effectively prevented by the administration of fucoidan component.