• Journal of Trauma and Injury
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• 제36권1호
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• pp.32-38
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• 2023

Purpose: This study aimed to identify the characteristics of patients injured by high-rotation cutting tools and the factors related to the severity of their injuries. Methods: Adult patients (≥18 years), who presented to the emergency department (ED) after a high-rotation cutting tool injury and who were registered in the Korean Emergency Department-based Injury In-Depth Surveillance (2011-2018) database, were included. Patients' demographic characteristics, injury-related factors, and Injury Severity Scores were collected. All included cases were categorized into two groups according to the tool that caused the injury: grinder versus nongrinder. The characteristics of the two groups were compared, and the factors associated with the severity of injuries were investigated. Results: Among 8,697 ED visits, 4,603 patients had been using a grinder and 4,094 had been using a nongrinder tool. The most frequently injured body part while using a grinder was the hand (46.4%), followed by the head (23.0%). While using a nongrinder tool, the most frequently injured body part was also the hand (64.0%), followed by the lower leg (11.4%). The odds of a severe injury were affected by patient age (odds ratio [OR], 1.024; 95% confidence interval [CI], 1.020-1.028) and using a grinder (OR, 2.073; 95% CI, 1.877-2.290). The odds of a severe injury using a grinder were higher in arm injuries (OR, 1.60; 95% CI, 1.40-1.83) and multiple-part injuries (OR, 1.998; 95% CI, 1.639-2.437). The odds of a severe injury using a grinder were lower for head injuries (OR, 0.481; 95% CI, 0.297-0.781). Conclusions: Injuries from grinders were more likely to affect the head and neck than nongrinder injuries, despite the lower severity. The current lack of regulations on grinders in occupational safety and health standards warrants relevant legislation and the development of applicable safety equipment.

• 한국운동역학회지
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• 제19권2호
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• pp.369-377
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• 2009

The purpose of this study was to determine the relationship between different soccer cleat designs and knee joint moments. Twelve physically active males (mean(SD): age: 26.4(6.2)yrs; height: 176.4(4.1)cm; mass: 74.0 (7.4)kg) were recruited Kinematic and force plate data were collected for all subjects during normal running and a $45^{\circ}$ cutting maneuver, called a v-cut. Both motions were performed at $4.0{\pm}0.2\;m/s$ on infilled artificial turf with three pairs of soccer cleats of different sole plate designs, and one pair of neutral running shoes. Inverse dynamics were used to calculate three dimensional knee joint moments, with repeated measures ANOVA and post hoc paired Student's t-test used to determine significance between shoe conditions. Significant differences were found in the extension moments of the knee for running trials, and for external rotation and adduction moments in the v-cutting trials. Knee moments were greater in v-cut than running, and the traditional soccer cleats (Copa Mondial and World Cup) tended to result in greater knee moments than the Nova runner or TRX soccer cleat. Cleat design was found to influence 3-dimensional knee moments in a v-cut maneuver. In the translational traction test, there were significant differences between all conditions. In the rotational traction test, friction with soccer shoes were greater than friction with running shoes. However, no differences were found between soccer shoes. Higher moments may lead to increased loads and stresses on knee joint structures, and thus, greater injury rates.

• 한국산림과학회지
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• 제98권3호
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• pp.225-230
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• 2009

본 연구에서는 Operations research 기법 중의 하나인 동적계획법을 이용하여 잣나무 임분의 총 수확량을 최대로 하기 위한 간벌 pathway를 검토해 보았다. 강원도 춘천시 강촌 모델림의 잣나무 임분 III영급을 대상으로 간벌 강도를 무간벌, 30% 및 50%의 간벌 수준을 적용하였으며, 임령 35년과 55년에서 총 2회의 간벌을 가정 하였고 벌기령을 70년으로 하였다. 임분 재적은 산림조사 자료의 분석을 통해 추정된 생장방정식을 이용하여 계산하였다. 동적계획법을 적용한 결과 총 9개의 pathway중 1차 간벌은 30%수준 그리고 2차 간벌은 50% 수준에서 시행하는 pathway가 총 수확량을 최대로 하는 것으로 나타났다.

• 한국산림과학회지
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• 제111권4호
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• pp.613-621
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• 2022

본 연구는 5차, 6차, 7차 국가산림조사 자료 중 아까시나무가 우점종인 표본점을 수집하여, 산림조사 차수별, 기후대별(온대 북부, 온대중부, 온대남부, 난대지역), 해발고별(100 m 단위) 흉고직경, 입목본수, ha당 재적 및 지위지수의 변화를 구명하고자 하였다. 또한 용재로서 사용을 위한 기준인 벌기령을 산정하였다. 그리고 변화 구명은 통계처리 기법 중 분산분석과 Duncan 검정으로서 이행하였다. 흉고직경의 변화를 보면, 당연히 산림조사 차수에 따라 증가하였고, 기후대별로는 온대남부 지역에서 가장 생장이 좋지 않았으며, 해발고별로는 301-400 m 지점에서 가장 생장이 떨어지는 것으로 나타났다. ha당 입목밀도는 산림조사 차수별, 해발고에 따라서 서로 간 차이를 보이지 않았으며, 온대중부 지역에서 밀도가 가장 높고, 온대남부 지역이 가장 낮은 밀도를 보였다. ha당 임분재적은 산림조사 차수에 따라 증가하였고, 온대북부·온대중부 지역과 온대남부·난대 지역으로 크게 두 그룹으로 구분되며, 해발고 201-300 m에서 재적생장량이 가장 높았다. 지위지수는 ha당 임분재적 변화와 유사한 결과를 보여 주었다. 그리고 아까시나무의 ha당 재적변화를 알 수 있는 생장량 곡선은 Weibull 함수식으로 추정하였으며, 임분재적은 임령 50-60년에 이를 때 약 200 m³에 달할 것으로 예측되었다. 아까시나무를 밀원 자원이 아닌 용재로 이용하기 위한 기준인 재적수확최대벌기령을 계산한 결과 34년으로 나타났다.