Purpose: This randomized controlled simulation study compared the automatic defibrillation (Auto-D) and manual defibrillation (Manual-D) modes used by nurses during in-hospital cardiac arrest (IHCA) simulation to evaluate the defibrillation decision (D-decision) accuracy and response times. Methods: Sixty nurses trained in advanced life support courses were randomly assigned to Auto-D (n=30) or Manual-D (n=30) groups. Participants completed four simulation scenarios with the following ECG rhythms: pulseless electrical activity, ventricular fibrillation-1 (VF-1), asystole, and VF-2. The primary outcomes included the D-decision accuracy and defibrillation time in two VF scenarios. Secondary outcomes included hands-off times. Qualitative data from the debriefings were analyzed using inductive content analysis. Results: The D-decision accuracy for the Auto-D group was higher than that for the Manual group (100% vs. 80%); however, the difference was insignificant (p=.056). The defibrillation time of VF-2 in the Auto-D group was shorter than that in the Manual-D group (p=.038). Hands-off times were similar across scenarios except for asystole case. The qualitative analysis revealed five themes regarding accuracy, time, and psychological burden. Conclusion: The Auto-D mode provides reliable D-decision accuracy and comparable response times, with a notably reduced psychological burden, supporting its use as a cost-effective strategy to improve IHCA responses and patient outcomes.

The domestic 1-ton truck market in Korea is rapidly shifting from diesel vehicles to LPG and electrified vehicles. However, hydraulic special-purpose vehicles, such as aerial work platforms, still require a reliable power take-off system to drive hydraulic equipment. In particular, conventional transmission-mounted PTO systems are difficult to apply to 1-ton LPG automatic-transmission trucks, despite the high market demand for automatic-transmission vehicles. In this study, a PTO system was developed for an aerial work platform based on a 1-ton LPG automatic-transmission truck. The developed system indirectly extracts engine power and transmits it to a hydraulic pump through a magnetic clutch. The hydraulic system was designed based on a flow rate of 20 L/min and a maximum pressure of 200 bar. The generated hydraulic power and required transmission torque were calculated using measured flow rate, pressure, and engine speed. The calculated pump input torque was confirmed to be within the allowable torque capacity of the 15 kgf·m magnetic clutch. The developed PTO-driven hydraulic system was applied to an actual aerial work platform, and the main working motions were confirmed to operate normally.

As the domestic 1-ton truck market shifts from diesel vehicles to LPG and electrified vehicles, securing hydraulic power for aerial work platforms based on 1-ton LPG automatic-transmission trucks has become an important technical issue because conventional PTO systems are difficult to apply. In this study, the boom motion driving characteristics of a PTO-driven hydraulic system previously developed for a 1-ton LPG automatic-transmission truck were experimentally evaluated. The tests were conducted for representative boom motions, including swing, lifting/lowering, and extension/retraction. The motion ranges were set to ± 25° for swing, 0°~20° for lifting/lowering, and 5.5~10 m for boom extension/retraction. The load conditions were set to no load, 68 kg, and 200 kg, and hydraulic pressure, flow rate at the hydraulic valve inlet, and engine speed were measured under low-speed and high-speed operation conditions. The results showed that the developed PTO-driven hydraulic system successfully performed the main boom motions, confirming its applicability as an alternative PTO system for boom operation in an automatic-transmission aerial work platform. In the lifting motion, the hydraulic pressure response increased with load, while high-speed operation resulted in increased flow rate and engine speed. Therefore, the developed PTO-driven hydraulic system is considered applicable to boom operation in a 1-ton LPG automatic-transmission truck-based aerial work platform. However, because hydraulic pressure, flow rate, and engine speed responses vary depending on load and speed conditions, further improvement of flow control and engine speed control is required for stable operation.

A needle-free automatic injection syringe is a device that delivers drugs into the skin and tissues using a high-speed fluid jet without using an injection needle. This technology is attracting attention as an efficient means of vaccine delivery in the veterinary and livestock fields that reduce the risk of cross-infection and require mass vaccination. In particular, animal vaccination provides various advantages over conventional needle injection methods in terms of worker safety, inoculation speed, and maintenance cost. This paper was conducted to solve the problem of pressure loss at the nozzle discharge side of the existing Jet Injector in designing the flow path of the animal vaccine-free automatic injection syringe nozzle. To this end, the flow rate of the air tank (receiver) was determined, the needleless injection was basically designed, and the simulation was performed to prove its validity. Through these series of processes, the design review of the driving part was completed, and through this, the nozzle and neck-up shape were proposed to obtain the desired performance. However, it is thought that more trial and error are needed to commercialize such a needleless injection to humans.

A needle-free automatic injection syringe is a device that delivers drugs into the skin and tissues using a high-speed fluid jet without using an injection needle. This technology is attracting attention as an efficient means of vaccine delivery in the veterinary and livestock fields that reduce the risk of cross-infection and require mass vaccination. In particular, animal vaccination provides various advantages over conventional needle injection methods in terms of worker safety, inoculation speed, and maintenance cost. Among these drivers, Jet Injector Nozzle's flow path design is very important in needleless automatic injection syringes. This paper was conducted to solve the problem of pressure loss at the nozzle discharge side of the existing Jet Injector in designing the flow path of the animal vaccine-free automatic injection syringe nozzle. To this end, CAE was performed and the optimum design of the flow path required by the company was performed, and a large flow rate was possible in the optimal shape design, but this focuses on the nozzle flow path, which requires a review of design additions of cylinders and motors on the rear side.

An automatic fire extinguishing system is installed inside the hull of the K2 main battle tank to protect equipment and crew members in the event of a fire and to enable continuous combat operations. This system detects heat sources and visible light to identify fires and discharges an extinguishing agent within milliseconds. However, there have been concerns that direct contact between the extinguishing agent(HALON 1301) and the driver-particularly on the arms or sides-could result in cold burn-like injuries. To mitigate this risk, the nozzle design of the fire extinguisher was modified to minimize crew exposure. Through modeling simulations and live fire suppression tests, it was verified that the redesigned nozzle still provides effective fire suppression. This study contributes to improving crew safety and enhancing the operational reliability of military equipment while reducing the risk of personnel injury and resource loss due to safety incidents.

이 논문은 S대학교 ‘사고와 글쓰기’ 교과에서 AI 자동 피드백 프로그 램 키위(KEEwi)를 활용한 수업 사례를 분석하고 그것이 지닌 효과와 한 계에 관해 탐색할 것을 목적으로 한다. 먼저 2장에서는 AI 자동 피드백 프로그램의 동향과 원리를 살펴보고 3장에서는 키위 프로그램을 활용한 수업 운영과 구체적 사례에 관해 설명하였다. 4장에서는 설문조사 분석 을 통한 학습자들의 프로그램 만족도와 교육 효과 및 한계에 관해 논의 하였다. 그 결과 이 프로그램은 즉각적이고 반복적인 피드백을 통해 학 습자의 학습 능률을 향상시킬 뿐 아니라 수업에 대한 흥미를 유발하여 글쓰기 역량을 강화하는 데 긍정적인 영향을 끼치는 것으로 드러났다. 또한 교수자에게는 글쓰기 교육의 보조 도구이자 협력자로 기능하며 학 습자 중심의 피드백 환경을 조성하는 데 기여하는 것으로 파악된다. 그 러나 키위 엔진은 완전한 대체 도구가 아니며 자체적인 오류와 문제를 가지고 있어 절대적인 평가 지표로 활용하는 것에는 한계가 있음이 확인 되었다. 이러한 연구는 대학 글쓰기 교양수업에서 AI 자동 피드백 프로 그램이 학습자와 교수자에게 끼치는 영향과 그 한계를 파악하는 데 도움 이 되리라 생각한다.

Fishways, particularly installed at the estuary, have a purpose to encourage fluent migration for migratory fishes, as well as amphidromous and even freshwater species. Not choosing the laborious traditional method of using traps, we assessed the efficiency of the two fishways installed at the west and east barrage of the Nakdong River estuarine barrage respectively, by analyzing the videos recorded through automatic monitoring system. We randomly selected 30 videos monthly at each fishways and identified what kind of fishes were using the fishways and categorised their behaviour such as size, time and whether they passed the monitoring system or not. As a result, a total 8 families 14 species were recorded by monitoring system, with the most dominance of Erythroculter erythropterus (Relative Abundance: 59.5%), followed by Micropterus salmoides (R.A: 19.9%) and Mugil cephalus (R.A: 9.9%). The monitoring system can capture passing fishes during night but the number of appearances of fish species at each hour of a day indicated significant diurnal activities (p<0.05). When fishes pass the monitoring system, approximately 70% of them passed through the monitoring device, while 17% of them showed fallback movement. Our finding indicates that species-specific characteristics of each fish are well represented through video monitoring method. In order to maximise advantages of using video monitoring, it is necessary to consider the installation point properly so that the monitoring system does not interfere with the movement of fish. Also, the utilisation of AI technology in the future is also necessary.

In this study, fire extinguisher system to which form fire extinguisher agents were adopted was applied to the combat vehicle crew room to apply fire extinguishing performance and acid gas safety that meet the national defense standards. As a result of evaluation and verification, the following conclusions were drawn. For standard fire sizes in the combat vehicle crew's standard model, we ignited using a mixture of Novec 1230 and Halon 1301 form extinguisher agent and released form extinguisher agent after 30 seconds to determine the fire extinguishing time. The amount of acid gas generated met the criteria in all cases. When the fire size was increased to 0.12m2 and a 2.0mm nozzle was used, all of the extinguishing time, the amount of acid gas generated, and the concentration of Novec 1230 met the criteria. Despite the more difficult conditions to extinguish the fire by making the fire larger, it was possible to confirm the extinguishing performance of the Novec 1230 form extinguisher agent and its safety against acid gas.

The importance of indoor air quality has significantly increased after the COVID-19 pandemic. This study analyzed the energy consumption of a ventilation system based on various operating methods considering indoor and outdoor conditions. From March to May 2024, experiments were conducted on ventilation systems installed in a hospital in Incheon, comparing the experimental and control groups. The results showed that using the bypass mode in the experimental group reduced total energy consumption by 25.34% compared to the control group. Additionally, utilizing the air-cleaner mode further reduced energy use. This study demonstrates that optimal use of bypass and air-cleaner modes can enhance energy efficiency. Further research is needed to verify long-term applicability under diverse conditions.

This study aims to propose new grading standards that can be applied to AI-based automatic sorting machines, reflecting current distribution and consumption trends. The current domestic grading standards for onions in South Korea are based on the “Agricultural and Fishery Products Quality Control Act”. They classify onions based on criteria such as uniformity, shape, color, and the presence of foreign matter. Onion grading standards are divided into four categories based on bulb diameter and weight. However, in the actual domestic market, onions are distributed according to a five-grade classification based on bulb diameter. Therefore, this study classified onions into eight grades, reflecting current distribution and consumption trends in the domestic market. These grades are applicable to AI-based automatic sorting machines. Marketable onions were classified into A1 (extra large) to A5 (extra small) based on the diameter of a single bulb. Onions used for non-marketable purposes (processing) were classified as grade B. Additionally, grade C and grade D were designated for processing and disposal, respectively. By establishing quality grading classifications that align with current distribution and consumption market trends as well as the operational characteristics of AI-based automatic sorting machines, we can expect improvements in work efficiency and reductions in distribution costs. Following this study, it will be necessary to establish comprehensive quality grading standards that include both external criteria (such as bulb weight and size) and internal criteria (such as detection of internal decay and disease occurrence).