This study aims to evaluate the effects of installing electrodeless induction lamps on the intact stability of a coastal angling fishing vessel. The objective is to assess whether these alternative lighting systems can improve or maintain vessel stability while offering enhanced energy efficiency compared to conventional metal halide lamps. To achieve this, an 8.55-ton class coastal fishing vessel was selected, and hydrostatic analyses were conducted based on three kinds of lighting configurations: (1) metal halide lamps, (2) electrodeless induction lamps, and (3) a combined system of both. Inclining tests were performed for each condition, and the results were evaluated in accordance with the Standards for Stability and Full Load Waterline of Fishing Vessels and the Safety Standards for Standard Fishing Vessel Types established by the Korean Ministry of Oceans and Fisheries and the Adoption of the international code on intact stability by the International Maritime Organization. The core variables analyzed include the metacentric height (GM), righting lever curves, maximum righting moment and heel angle at maximum moment. These variables were used to assess the intact stability of the vessel under each lighting configuration. Inclination tests and hydrostatic analyses were performed using K-Ship and confirmed that the fishing vessel met all MOF and IMO stability criteria under various loading conditions and lamp configurations. Even when both metal halide and induction lamps were installed, the vessel satisfied the most stringent stability requirements with only a slight reduction in initial metacentric height. These results indicate that replacing or supplementing traditional lamps with induction lamps does not compromise vessel stability.

A centrifugal cyclone dust collecting apparatus includes a hydro cyclone dust collecting apparatus for separating solid or liquid using liquid or suspension as a medium. In this study, the formation mechanism and improvement of air core and inner air layer were confirmed through Particle Image Velocimetry. These results showed that the modified experimental model was designed in the conventional method suitable for the separation of juvenile fish and eggs. The inlet speed of the multi-stage hydrocyclone dust collector, which can increase the inlet velocity and minimize floatage in the turbulence chamber, was increased from 0.15 to 0.30 m/s. As a result, the air core was stably formed, the inner air layer was increased with increasing speed. In addition, the dust collecting efficiency of egg and juvenile fish was 97.8% on average, It can infer that this system confirmed the ability to efficiently collect particles of 40 μm or more.

This study aims to estimate the species, size and shape of fish using a non-contact 3 dimensional pattern laser so that this preliminary test was carried out to understand the structural feature and length of goldfish according to water turbidity and depth in the aquacultural tank. 3-D pattern laser could clearly detect its morphological shape except the caudal fin due to soft tissue. Since the sensing strength of line laser light according to depth has sufficient power, it is possible to measure its depth and structural feature in the detected range. The result showed that the measured error of individual’s fork length was less than ±1% in the water using 3-D pattern laser, when compared with the measured value in the air.

Recently LED fish-attracting lamps have been more widely used in fisheries as low-cost and high-efficiency fishing gear, and development of long-life high-efficiency lamps is required through the design of LED packages to optimize heat resistance. This study developed an improved LED fish-attracting lamp with excellent heat performance, which was verified using a numerical model. Heat-resistance design factors such as the heat-radiation fin shape, PCB type, and LED chip count were investigated and optimized. Comparison with a commercial 180-W LED fishing lamp showed that the increase in initial temperature was 40% higher than that of the surrounding LED chip because of design errors in contact thermal resistance. The 250-W LED lamp developed in this study has a characteristic with thermal rising in linearly stable according to the heat source. In addition, luminance efficiency was improved by 20-65% by using flow-visualization simulation. A decrease of 45% in total power consumption with a fuel-cost reduction of over 55% can be expected when using these optimized heat release design factors.