• 한국도로학회논문집
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• 제19권6호
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• pp.13-21
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• 2017

PURPOSES : In this research, an SB3-level roadside barrier for a highway transition zone that meets the newly established guide Installation and Management Guide for Roadside Safety Appurtenance is developed. Its performance is evaluated by a numerical simulation and real-scale vehicle impact test. METHODS : The commercial explicit dynamic software LS-DYNA is utilized for impact simulation. An FE model of a passenger vehicle developed and released by the National Crash Analysis Center (NCAC) at George Washington University and a heavy goods vehicle (HGV) model developed by the TC226/CM-E Work Group are utilized for impact simulation. The original vehicle models were modified to reflect the conditions of test vehicles. The impact positions of the passenger vehicle and truck to the transition guardrail were set as 1/2 and 3/4 of the transition region, respectively, according to the guide. RESULTS : Based on the numerical simulation results of the existing transition barrier, a new structural system with improved performance was suggested. According to the result of a numerical simulation of the suggested structural system, two sets of transition barriers were manufactured and installed for real-scale vehicle impact tests. The tests were performed at a test field for roadside safety hardware of the Korea Highway Corporation Research Institute. CONCLUSIONS : The results of both the real-vehicle impact tests and numerical simulations of the developed transition barrier satisfied the performance criteria, and the results of numerical simulation showed good correlation with the test results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.309-313
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• 2006

Many researchers have studied on the lightness of automobile. These researches are such as a body shell, sub frame, fuel tank, engine etc. The transmission Part is a magnitude one in the aspect of weight. A drive shaft (propeller shaft) transmits the engine power to rear differential gear assembly. It is used in the compact car that is a single drive shaft. But in the case of long body cars such as SUV (Sports Utility Vehicle), truck and large vehicle, two or three divided drive shaft are used to prevent the vibration damage from a drive shaft that has been taken high torsion and rotation. This multi-divided drive shaft structure is so heavy because it is assembled by yoke, center bearing and solid spline axis. When the rear axle move up and down, the spline shaft adjust the variation of a length between the transmission and rear axle gearbox. In this paper, it is studied in the experimental method that is a bending vibration characteristic of slip in tube shaped propeller shaft. This type propeller shaft is developed to combine the spline axis with drive shaft and can be light in weight of transmission part.

• 한국건축시공학회지
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• 제16권4호
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• pp.381-388
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• 2016

제설전진기지는 제설작업을 신속하게 수행하기 위한 물리적인 제반요건으로서, 제설대상 도로구간에 필요한 제설차량 및 장비를 보관한 차고와 제설제를 비축한 창고, 관리시설 등을 구비한 시설물로 정의할 수 있다. 본 연구는 제설전진기지의 시설기준을 마련하기 위한 기조적 연구로서 해외의 기준을 고찰하고 고속국도 및 일반국도, 지방도를 대상으로 국내 제설전진기지의 실태를 조사하였다. 사례조사결과 창고형태의 전진기지가 없고 야외에 제설제를 보관하고 있는 경우도 많은 것으로 나타났다. 실태조사를 바탕으로 배치, 규모, 평면, 구조체로 나누어 문제점을 분석하고 제설전진기지의 설계시 고려사항을 제시하였다.

• 한국BIM학회 논문집
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• 제12권4호
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• pp.61-69
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• 2022

Earthmoving operations account for approximately 25% of construction cost, generally executed prior to the construction of buildings and structures with heavy equipment. For the successful completion of earthwork projects, it is crucial to constantly monitor earthwork equipment (e.g., trucks), estimate productivity, and optimize the construction process and equipment on a construction site. Traditional methods however require time-consuming and painstaking tasks for the manual observations of the ongoing field operations. This study proposed the use of a GPS sensor embedded in a smartphone for the tracking and visualization of equipment locations, which are in turn used for the estimation and simulation of cycle times and production rates of ongoing earthwork. This approach is implemented into a digital platform enabling real-time data collection and simulation, particularly in a 2D (e.g., maps) or 3D (e.g., point clouds) virtual environment where the spatial and temporal flows of trucks are visualized. In the case study, the digital platform is applied for an earthmoving operation at the site development work of commercial factories. The results demonstrate that the production rates of various equipment usage scenarios (e.g., the different numbers of trucks) can be estimated through simulation, and then, the optimal number of tucks for the equipment fleet can be determined, thus supporting the practical potential of real-time sensing and simulation for onsite equipment management.

• Journal of Chest Surgery
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• 제13권3호
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• pp.212-218
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• 1980

A severe crushing injury of the chest produce a very striking syndrome referred to as traumatic asphyxia. This syndrome is characterized by bluish-red discoloration of the skin which is limited to the distribution of the valveless veins of the head and neck. And also if it is characterized by bilateral subconjunctival hemorrhages and neurological manifestations. But these clinical entities faded away progressively in a few weeks. Apporximately 90% of the patients who live for more than a few hours will recover from traumatic asphyxia when it occurs as a single entity. And so, death results from either severe associated injuries of from subsequent infection, rather than from pulmonary or cardiac insufficiency in traumatic asphyxia. We have experienced 4 cases of traumatic asphyxia with severe crushing thoracic injuries at department of the chest surgery, Captial Armed forces General Hospital during about 3 years from April 1977 to Aug. 1980. The 1st 22 year-old male was struct 2$\frac{1}{2}$ ton truck on the road and was transferred to this hospital immediately. He had taken tracheostomy due to severe dyspnea with contusion pneumonia and for removal of a large amount of bronchial secretion. The 2nd case was 23 year-old male who was got buried in a chasm. In this case, the heavy metal post tumbled over him back while at work. The 3rd case was 39 year-old male who leapt out of a window in 5th story while fire broke out in living room by oil stove heating. He had multiple rib fracture with right hemothor x and right colle's fracture and pelvic bone fracture. The last 22 year-old male was run over by a gun carriage. The wheel of this gun carriage passed over his thorax and right chin. He was brought to this hospital by helicopter. when he was first examined at emergency room, he was in semicomatose state and has pneurmomediastinum with multiple rib fracture and severe subcutaneous emphysema. As soon as he arrived, bilateral closed thoracostomy was performed and cardiopulmonary resuscitation was done. In hospital 8th weeks, chest series showed fibrothorax in right side even if chest wall stabilized. All 4 cases had multiple petechiae over their facees and chest and bilateral subconjunctival hemorrhages referred to as traumatic asphyxia. 3 cases except one case who received splenectomy, had been suffered from contusion pneumonia and had been treated with respiratory care. In these 3 cases, they had warning of impending injury before accident, and took a deep breath hold it and braces himself. And also, even if he had not impending fear in remaining one case, he had taken a deep breath and had got valsalva maneuver for pulling off the heavy metal post. Intrathoracic pressure rose suddenly and resulted to traumatic asphyxia in this situation. All these cases were recovered completely without sequelae except one fibrothorax, right.

• 한국산림과학회지
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• 제107권2호
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• pp.166-173
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• 2018

본 연구는 목재운송 효율을 도모하기 위하여 목재운송차량이 대형화 되어감에 따라 대형 목재운송차량의 원활한 임도 통행을 위한 노면지지력 확보할 수 있는 노반 시설기준을 마련하고자 실시하였다. 산림기술경영연구소 관내 연약지반 임도 노면에 대하여 토목섬유를 활용하여 적정 골재배합비로 조성한 노반의 두께별 노면지지력 강화효과를 분석한 결과는 다음과 같다. 토목섬유를 활용하여 상굴식으로 노반을 0.2 m 이상 포설한 시험구간은 노면지지력이 CBR 15% 이상으로 양호한 것으로 나타났다. 그러나 토목섬유 종류별 노면지지력 보강효과는 큰 차이가 없었고, 상치식으로 조성한 구간의 경우 노면지지력이 미흡한 것으로 나타났다. 따라서 연약지반 구간에서는 상굴식으로 터파기 한 후 토목섬유를 부설하고, 노반층 두께를 0.2 m 이상 조성한 후 표층을 포설하여야 대형 목재운송차량의 원활한 통행에 필요한 노면지지력 확보가 가능할 것으로 판단된다.

• 한국화재소방학회논문지
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• 제33권3호
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• pp.138-142
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• 2019

골든타임의 확보 방안으로 충북 청주시에서 시행하는 긴급차 우선신호체계 운영 결과를 분석하였다. 화재현장에 도착하기까지 도로상의 극심한 교통정체, 긴급차 앞으로 끼어드는 차량, 긴급차 길터주기에 비협조적인 차량 등 출동 중에 나타나는 장애요인들은 심각한 상태이다. 이와 같은 도로상의 장애문제를 해결하기 위하여 긴급차 우선신호체계를 도입하는 것은 반드시 필요하다. 2017년 4월부터 2018년 6월까지(1년 2개월, 426일) 출동시간과 날짜, 긴급차의 이동거리와 시간, 교통신호 통제구간과 통과시간, 단축시간 등을 측정하였다. 293개의 출동회수 중 교통이 혼잡하고 출동이 잦은 5개의 구간에서 140개의 선택하였다. 교통신호시스템을 통제한 결과는 놀라웠다. 총괄적으로 신호를 통제하지 않을 때에는 1 km를 주행하는데 3 min 3 s가 결렸지만 신호를 통제하여 긴급차를 우선통행하도록 하는 경우에는 1 km를 1 min 23 s에 주행하여 처음의 45.4% 밖에 걸리지 않았다. 즉 15 min 걸리던 주행시간을 6 min 49 s로 줄인 것이다. 이러한 결과를 볼 때 긴급차 우선신호시스템은 가능한 한 빨리 전국적으로 실시하여야 할 것이다.

• Korean Chemical Engineering Research
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• 제56권4호
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• pp.479-495
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• 2018

본 연구에서는 자동차배출화학물질 중 발암성 및 돌연변이 유발 물질인 PAHs (Polycyclic Aromatic Hydrocarbons)의 다매체 간 거동 모델링, 농도 분포, 그리고 영향평가를 수행하였다. S시의 차량 통계와 PAHs의 배출계수를 이용하여 PAHs의 배출량을 산정하였고, 도시의 불투수면적에서 대기-토양의 물질이동 제한조건을 바탕으로 다매체 퓨가시티 모델링을 수행하였다. 다매체 퓨가시티 모델을 이용하여 정상상태에서 환경 매체내 PAHs의 농도 분포를 예측하고(Level III), 각 모델 변수에 대하여 몬테카를로 민감도 분석을 바탕으로 비정상상태에서 환경 매체내 PAHs 잔류량 및 매체 간 물질 이동으로 인한 매체별 농도분포와 위해성 평가를 수행하였다(Level IV). S시의 경우 배출된 PAHs중 Fluoranthene이 네 가지 환경 매체(대기, 수계, 토양, 침전물)에서 모두 가장 높은 잔류농도(60.0%, 53.5%, 32.0%, 33.6%)를 보였으며 침전물에서 가장 높은 농도(80%이상)로 잔류하였다. 34년 동안 S시 환경 매체 중의 PAHs 농도 변화 분석 결과, 모든 환경 매체에서 PAHs 잔류량은 1983년부터 2005년까지 증가하였고, 이후 2016년까지 감소한 것을 확인하였으며, 각각 환경매체에서 트럭을 포함한 중량차량(Heavy Duty Vehicles, HDVs) 배출가스의 PAHs 농도 기여도가 큰 것으로 나타났다. 매체 별 PAHs 농도는 토양과 수계에서 34년간 기준치보다 작은 값을 보였으나, 대기중 PAHs농도는 권고치를 초과하는 농도값을 보였다. 본 연구 결과를 통해 지난 30여년 동안 대도시 자동차 배출 화학물질인 PAHs의 환경 중 거동 및 위해성을 평가를 통하여 PAH물질 관리 및 규제의 필요성을 제시하고, 다양한 환경 매체 내 독성화학물질 관리 및 모니터링에 기여할 수 있을 것으로 기대된다.