본 연구는 교량공사에서 안전관리비의 구성 불균형(인건비 편중)을 진단하고, 위험도에 연동된 간명한 예산 프레임을 제안하고자 한다. 건설 7개 프로젝트 집행 데이터를 활용하여 (i) 파레토 관점에서 지출 집중을 확인하고, (ii) 인건비를 단일 핵심변수로 한 단순회귀 (SCP)로 총액 예측력을 검증했으며, (iii) 교량 연장·형식·기초·교통전환·공사기간으로 구성된 위험도 지표와 안전시설강화(시설+PPE) 간의 정합성을 점검하였다. 분석 결과, 인건비는 평균적으로 가장 큰 비중을 차지했고, SCP(Safety Cost Prediction) 모델(Y=2.07X−286백만, R²=0.859)은 총 안전관리비 변동을 높은 설명력과 신뢰도를 제 시한다. 예측성능은 실무 수용 수준이었으며, 일부 현장은 예측–실집행 괴리를 통해 안전 시설 강화를 위한 집행의 부족 또는 확대와 같은 구조적 신호를 제시하였다. 위험도–구성 비 진단에서는 등급이 높아질수록 안전시설강화 비중이 체계적으로 확대되는 패턴이 확 인되었고, 사고지표(건수) 비교에서도 인건비 비중이 높다고 해서 안전이 담보되지는 않 음을 보였다. 이에 따라, 본 연구는 인건비 상한 60%, 위험등급별 총액 가산(저 0%·중 +5%·고 +10%), 안전시설 강화를 위한 최소선(저 ≥26%·중 ≥32%·고 ≥36%)으로 구성된 3중 프레임을 제안하고자 한다. 이 프레임은 총량–구성–위험도를 동시에 관리하여, 고위 험 현장에서 안전시설강화 수준을 안정적으로 끌어올리는 동시에, 초기 단계부터 간단하 고 일관된 의사결정을 가능하게 한다. 표본과 점수폭의 제약, 단일변수 모형의 한계를 인정하면서도, 제안 규칙은 투명성·실행성·확장성 측면에서 현장 적용 가치가 높다.
This study compared the physical properties and catch performance of gillnets made from biodegradable PBEAS (butylene succinate-co-adipate/terephthalate-co-ethylene succinate) resin with those of conventional PA (polyamide) gillnets in coastal gillnet fisheries targeting Pampus argenteus. Mechanical tests showed that PBEAS nets showed tensile strength and elongation similar to PA nets. In field trials, the total catch weight of PBEAS nets (596.6 kg, 261 individuals) was slightly higher than that of PA nets (535.1 kg, 248 individuals). The catch of Pampus argenteus was also greater in PBEAS nets with increases of approximately 51.0% in number and 35.8% in weight although the difference in total catch weight between the two net types was not statistically significant (Wilcoxon signed-rank test, p = 0.25). The size distribution of Pampus argenteus ranged from 12 to 28 cm fork length (FL) for both nets, with PBEAS nets showing more individuals particularly in the 16 – 20 cm range. Bycatch patterns were similar between the two gears where Chelidonichthys kumu, white Argyrosomus argentatus, and Zeus faber identified as dominant species. These findings clearly demonstrate the practical potential of PBEAS biodegradable gillnets and highlight their promise as an alternative to PA nets for promoting sustainable fisheries.
Fish school monitoring technology is utilized for various purposes, such as boat fishing and resource surveys. With advancements in information and communication technology, this technology has expanded its application to remote areas. Its significance has grown in fishing sites, particularly for improving the efficiency and cost-effectiveness of set-net fishing. Set-net fishing gears are not limited to coastal areas, but are also installed in inland and remote sea regions. Consequently, fishermen require technology that allows them to quickly transmit information about approaching fish schools and enables them to perform long-term monitoring. The development of remote monitoring technology for set-net fish schools must consider crucial design factors such as communication range, transmission speed, power consumption of information modules, and operational expenses. In this study, we developed a low-power remote monitoring module for set-net fish school based on WCDMA. The module was specifically designed to minimize power consumption, allowing for communication over long distances and extended operation times in set-net fishing applications. Furthermore, we developed a web server software application that enables remote access to fish schools and provides real-time weather information. The performance of the developed module was evaluated through set-net fishing site application and experiments with moving ships on the sea. The experimental results demonstrated that the remote monitoring system, consisting of the developed low-power remote monitoring module for set-net fish school based on WCDMA and a fish finder, had an average power consumption of 4.6 W, a maximum communication range of 22.84 km, and a data transmission and reception rate of 98.79%. The maximum fish school information transmission and reception rate was 97.26%.
In this study, we developed a thermoelectric generation system for coastal fishing boats that allows for a high-density arrangement of thermoelectric modules, verified the improvement in performance by conducting comparative analysis between field test results and results from previous studies. The developed thermoelectric generation system was installed in a 3-ton gill-netter to analyze the engine revolutions per minute and energy production per day for each fishing process over a period of 20 days. From the experimental results, the maximum electric energy generated was 207.1 Wh, the minimum was 53.93 Wh and the average electric energy was 129.98 Wh. In accordance with the increasing of the engine r.p.m., the maximum electric production was 183 W at 1,500 r.p.m. It was approximately 80.5% of designed capacity, 227.2 W. Considering the result in the earlier research was 50.7% of designed capacity, 115.8 W. It was improved by 30% compared to the earlier one. The fishing operation was classified as departure, fishing and arrival. From the result on production analysis of electric energy, the composition of energy was 63% in fishing, 19.5% in departure and 17.5% in arrival. The electric energy production per unit hour was 42.8% in arrival, 32.9% in departure and 24.3% in fishing.
With the advent of the fourth industrial revolution, the digital transformation craze has intensified in diverse industries, such as finance, automotive, health care and agriculture. However, relative to industry demand, there is only few domestic research on digital transformation of small traders and no one has implemented empirical study on this field at all. Thus, the study conducted an empirical study to measure the digital transformation intention of domestic small traders. In the early days of domestic business start-ups, we searched for factors affecting the digital conversion intention of small business owners and designed an integrated framework to explain the causal relationship between factors. This study not only expanded and refined the scope of related research but also suggested the direction of another research that was not presented in previous research. However, there are limitations in many ways as much as the initial stage of a specific field of small business owners. There are limitations in explaining the overall perception of Korean small business owners. Therefore, in future studies, it is necessary to study more deeply by presenting more specific and various variables. In addition, although the number of respondents was sufficient in the process of empirical analysis, it is considered that the respondents are not enough to universalize the research result as a traditional small business person who did not convert all digital. It is necessary to carry out a comparative analysis by dividing the two groups in more detail and more specifically in the future study. The result of this study can suggest the direction for accelerating small traders’ digital transformation intention in terms of practical view, and provide useful references which can support the theoretical foundation for researchers who will perform future related research in terms of academic view.
We measured the target strength according to the swimming tilt angle and size change for Pacific herring at the frequency of 70 kHz as the basic database in order to estimate its abundance as well as density in the survey area using the hydroacoustical method. The number of the sample used in this study was 14 individuals, and its size distribution by fork length ranged between 20.3 and 29.8 cm and wet weight was measured between 187.6 and 269.9 g. The variation of TS according to the swimming angle (-30~30°) was measured between 10.3 and 18.8 dB in frequency range, the highest value was measured at head-down of Pacific herring in the tilt angle range between 5 and 9 deg. of its swimbladder. The relationship between TS–FL of herring was the same as TS = 20log10 (FL) – 66.79 when its swimming tilt angle in the daytime (3.8 ± 6.0°) and nighttime (-3.2 ± 13.6°), respectively.
The renewable energy sources can be thought of one of the major measures to reduce greenhouse gas emissions in the industries. However, the utilization technology for those sources is approaching in the different matters. One of them, thermoelectric generation might be applicable to fishing industry. A various of internal combustion engines are used in a wide range of fisheries. After the ignition process, the heat passed out from the exhaust outlet. Recycling the heat could be not only an energy source but also reduction of green gas emission. Therefore, this study was designed to verify the feasibility of generation from wasted exhaust gas and analyze the performance. The designed experiment devices were connected with a data logger and an electric loader to quantify the currency and voltage. The devices were installed in a coastal fishing vessel for a gillnet fishery. During the whole fishing trips, the amount of generation was measured by engine rpm and the fishing operation procedures including vessel operations. At the maximum 1,500 rpm in the practical range, the generation amount was 113.6 W. The amount difference in relation to connection method was within 5 W: serial connection was 111.4 W and parallel connection was 115.8 W.
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.
This study aims to estimate the Green-House-Gas emissions from domestic farmed flounder in the southern sea and Jeju-Do, where is mainly produced, by the assessment of energy consumptions and GHG emissions from domestic fish farms for establishing reduce standards of greenhouse gas from a sustainable perspective. It needs to analyze such GHG emission components as feed, electricity, fuel, fixed capital, fish respiration, and liquid oxygen in two locations by 4 stage running water type farm size of small, small and medium, large and medium, large scale. The result showed that the mean GHG emissions were 36.83 kg·CO2/year in the southern sea and 24.33 kg·CO2/year in Jeju-Do, respectively, in the stage of production per fish 1kg at 2 locations and farm size from domestic farmed flounders, and it will give to be useful for policy, planning, and regulation of aquaculture development with establishing GHG reduction standards.
A model net experiment of the gape net for anchovy in Jindo, Jeollanam-do was carried out to investigate the net shape and hydrodynamic resistance using circulating water channel. The model net was made 1/33 down scale by Tauti’s similarity method and the range of experimental current speed was from 0.5 knot to 3.5 knot (increasing 0.5 knot interval). The net mouth height in 0.5 knot of the minimum experiment current speed was shown 26.0 cm (full-scale conversion value 8.58 m). The net mouth height and mouth area in 1.5 knot of the same current speed with a gape net fishing ground were shown 20.0 cm (full-scale conversion value : 6.60 m) and about 507.9 cm2 (full-scale conversion value : 55.31 m2). The net mouth height and area were decreased with increase the experimental current speed. The hydrodynamic resistance of the model net in 1.5 knot current speed was shown 1.11 kgf and the value of full-scale conversion by Tauti’s method was shown 3.996 ton.
The worldwide abundance of various jellyfish appears to have increased in coastal ecosystems in recent years. The enormous jellyfish blooms cause a variety of problems for the local ecology, fisheries, and aquatic-sports in coastal locations. In this study, jellyfish sting protection net was installed to ensure the safety and reduction of the inflow into the Haeundae beach. In order to confirm the stability of the protection net, the tension for protection net was measured from variation of current speed. The periods for maximum tension were observed correspond to the periods of maximum current speed. The maximum tension for protection net was measured up to 4,100 kg. From field evaluations, the jellyfish sting protection net has demonstrated to stability from the current and tide in the Haeundae beach.