전기 및 수소자동차 주차장의 화재위험성 완화에 관한 연구

임옥근 한국화재소방학회 2024 한국화재소방학회논문지 Vol.38 No.2

전기자동차나 수소자동차와 같은 환경친화적 자동차의 사용이 증가하면서 관련 기반시설도 빠르게 확충되고 있으며 주변의 주차장에서도 흔하게 볼 수 있게 되었다. 주차장의 화재안전설계는 기존에 확보한 내연기관자동차의실화재실험 자료를 바탕으로 이루어지고 있어 환경친화적 자동차의 특성을 반영할 필요가 있다. 본 연구에서는 내연기관자동차, 전기 및 수소자동차의 실화재실험 자료를 분석하여 공차중량과 배터리용량에 따른 열방출률을 분석했다. 전기와 수소자동차의 에너지원인 배터리나 수소가스를 제외할 경우 화재성장속도나 최대열방출률은 내연기관자동차와 유사한 형태를 보였다. 전기자동차의 배터리에서 점화할 경우 빠른 화재성장속도를 보였으며, 수소자동차의저장용기에서 온도감응형 압력배출장치가 작동하는 경우에는 순간적으로 10 MW 이상으로 열방출률이 상승했다. 주차장의 화재안전성 향상을 위해서는 차량에 사용되는 플라스틱 내장재나 배터리 용량의 증가를 반영하여 공차중량이나 내화구조를 설계해야 하며, 화재가혹도가 큰 차량을 기준으로 소방시설을 설치할 필요가 있다. As the use of eco-friendly vehicles, such as electric and hydrogen vehicles, is rapidly increasing, the related infrastructureis also expanding, and they have become common in parking areas. The fire safety design of a car park is based on theexisting data of internal combustion engine vehicles; therefore, the characteristics of eco-friendly vehicles must be reflected. This study investigated the heat release rate of internal combustion engine vehicles, electric vehicles, and hydrogen vehiclesusing real-scale fire test data and analyzed the effects of curb weight and battery capacity. The fire growth rate andmaximum heat release rate of electric and hydrogen vehicles were similar to those of internal combustion engine vehicles,except for the batteries and hydrogen gas, which are the energy sources of electric and hydrogen vehicles, respectively. When ignited from the battery of an electric vehicle, the fire grew rapidly. When the thermally activated pressure reliefdevice was activated in the storage vessel of a hydrogen vehicle, the heat release rate instantaneously increased to 14.5 MW. To improve fire safety in car parks, the curb weight and fire resistance structure must be designed to reflect the increasein plastic interior materials and battery capacity of vehicles, and firefighting facilities must be installed based on vehicleswith greater fire severity.

계량정보학적 분석을 통한 소방안전분야 연구동향

임옥근 한국화재소방학회 2023 한국화재소방학회논문지 Vol.37 No.1

Various studies have been conducted to minimize property damage and casualties caused by fire accidents, which occurover 40,000 times annually on average. The research papers published in the Fire Science and Engineering journal indexedin the Korea Citation Index and the Fire Technology journal indexed in the Science Citation Index Expanded databases overthe last 10 years were analyzed utilizing text-mining techniques. Similar research papers published these two journals wereexplored and significant differences in perceptions were identified. Recently, the proportion of studies on “Wild-Urban-Interface (WUI) fire” and “Battery fire” published in the Fire Technology journal has increased; however, “Firefighterorganization” related research papers are being actively published in the Fire Science and Engineering journal. Aquantitative analysis of the studies on fire incidents can provide significant information on developing new policies essentialto reducing fire damage. 연평균 4만건 이상 발생하고 있는 화재사고로 인한 인명 및 재산의 피해를 최소화하기 위해 다양한 연구들이 수행되고 있으나 화재로 인한 사상자수는 증가하는 추세를 보이고 있다. 본 논문에서는 한국학술진행재단등재지인 한국화재소방학회논문지와 science citation index expanded (SCIE) 논문지인 Fire Technology에서 최근 10년간 게재된 논문들을 텍스트마이닝기법을 활용하여 연구주제들을 분석했다. 유사한 연구주제 뿐만 아니라 국내 혹은 국외에서만연구되는 주제들을 확인할 수 있었으며, 유사한 주제라도 연구방향이나 연구자의 관점에 차이가 있었다. 국외에서는산불이나 배터리화재에 대한 연구가 최근에 급격히 증가하는 추세를 보이나 국내에서는 소방공무원의 직업적 특성에 관한 연구가 증가하는 추세를 보였다. 이런 분석결과는 화재로 인한 피해를 저감하기 위한 소방분야 연구 및 정책방향 수립에 활용될 수 있을 것이다.

전단연결재의 내화성능에 대한 유한요소해석

임옥근,최승관 조선대학교 공학기술연구원 2018 공학기술논문지 Vol.11 No.4

A shear connection between the steel beam and concrete slab determines the stability of composite beams. An extensive numerical study to evaluate the resistance of the shear connection in a solid slab at high temperature was conducted. Three-dimensional thermo-mechanical finite element models were developed using a dynamic explicit method and concrete damaged plasticity model. Temperature-dependent plasticity parameters of the concrete model were proposed, and the accuracy of the developed model was obtained against experimental data. This investigation has revealed that a stud shearing failure occurs regardless of temperatures, and its shearing location changes in accordance with a rise in temperature. A new strength reduction formula has been presented to estimate the resistance of the shear connection at high temperatures.

룸코너 시험을 이용한 배관용 보온재의 난연성능 분석

임옥근,남동군,장효연 한국화재소방학회 2019 한국화재소방학회논문지 Vol.33 No.4

Reaction-to-fire performance of pipe insulation materials should be approved in accordance with KS standards prior toinstalling water-based suppression systems because several fire accidents are initiated from insulation materials aroundceilings or concealed space. A small room test to evaluate the reaction-to-fire performance of the polyethylene foam andelastomeric pipe insulation materials was conducted according to ISO 20632. Different fire growth rate and heat release rateare observed depending on the materials and construction methods. In order to improve a fire safety, the reaction-to-fireperformance of pipe insulation material needs to be subdivided with regard to the heat release rate and smoke generation. Furthermore, the characteristics of the applying space are also required to be considered. Subsidiary materials for installationprocess such as tape and adhesive are found to provide an adverse effect to maintain a fire safety. 천장이나 배관에 설치된 보온재의 연소로 인해 화재가 확산되는 사례가 발생함에 따라 수계소화설비의 배관보온재는 난연재료 성능 이상의 것을 사용하고 있다. 배관보온재의 일부분을 시편으로 가공하여 난연성능을 평가하고있지만 설치환경을 고려한 실규모시험을 통한 평가는 이루어지지 않고 있다. 본 연구에서는 국내에서 널리 사용되고있는 발포폴리에틸렌폼 및 고무발포보온재를 실규모 시험기준인 ISO 20632에 따라 시험하고 유럽의 난연성능 분류기준과 비교하였다. 배관보온재 재료별로 상이한 난연성능을 보였으며, 특히 발포폴리에틸렌폼보온재의 경우 시공방법에 따라 화재성장율 및 열방출율이 달라졌다. 화재발생 시 배관보온재로 인한 연소확산을 지연시키기 위해서는설치하는 대상공간의 특성을 고려한 난연성능 적용이 필요하며, 시공 시 사용하는 접착제와 테이프 등 부자재의 난연성 또한 고려해야 함을 확인할 수 있었다.

LTCC 기술을 이용한 집적형 컴라인 대역 통과 여파기

임옥근,김용준 한국마이크로전자및패키징학회 2004 마이크로전자 및 패키징학회지 Vol.11 No.1

무선 이동 통신에 응용할 수 있는 소형의 집적된 형태의 여파기를 LTCC기술과 인터디지털 커패시터 (Interdigital capacitor)를 가진 컴라인 타입(Combline type)의 구조를 이용해 구현했다. 또한 T 패턴을 가지는 마이크로스트립(Microstrip)타입의 공진기를 이용해 LTCC 기판의 전기적 성능을 측정했다. 구현된 여파기는 인터디지털과 컴라인 구조를 이용해 2.7mm${\times}$2.03mm의 비교적 소형으로 구현할 수 있었고 5.09 GHz의 중심주파수에서 1.8 dB의 삽입손실, 37.6 dB의 반사손실, 그리고 280 MHz의 대역폭을 가졌다. 제안된 여파기는 작은 크기와 간단한 구조로 인해 여러 가지 LTCC기판의 집적형 여파기로 응용될 수 있을 것이다. A compact embedded tapped-line combline filter with interdigital capacitors using low temperature co-fired ceramic (LTCC) technology for wireless application is proposed. Also, in-situ measurement using T-pattern microstrip resonator was performed to acquire exact knowledge of electrical properties of the LTCC substrate. The proposed filter makes it possible to realize a relatively small size, 2.7mm${\times}$2.03mm. by employing interdigital and combline structure. It shows 1.8 ㏈ insertion loss, 37.6㏈ return loss, and 280 MHz bandwidth at the center frequency of 5.09 GHz. Its small size and simple structure make it a good candidate as an integrated filter for various LTCC substrates.

Experimental studies on the behaviour of headed shear studs for composite beams in fire

임옥근,최승관,강성욱,권민재,최정윤 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.6

Steel and concrete composite structures are commonly applied in multi-story buildings as they maximise the material strength through composite action. Despite the popularity of employing a trapezoidal deck slab, limited experimental data are available under elevated temperatures. The behaviour of the headed shear stud embedded in a transverse trapezoidal deck and solid slab was investigated at both ambient and fire conditions. Twelve push-out tests were conducted according to the ISO 834 standard fire utilising a customised electric furnace. A stud shearing failure was observed in the solid slab specimen, whereas the failure mode was changed from a concrete-dominated failure to the stud shearing in the transverse deck specimen with an increase in temperature. Comparisons between the experimental observations and design requirements are presented. The Eurocode design guidance on the transverse deck slab gives a highly conservative estimate for shear resistance. A new design formula was proposed to determine the capacity of the shear connection regardless of the slab type when the stud shearing occurs at high temperatures.

배관보온재 난연성능 기준 분석

임옥근,남동군,정재한 한국화재소방학회 2019 한국화재소방학회 학술대회 논문집 Vol.2019 No.춘계

Zonisamide의 항경련 효과에 관한 임상적 연구

장환일,이해선,전성일,이경규,정미라,윤도준,송지영,오동재,임옥근 大韓神經精神醫學會 1992 신경정신의학 Vol.31 No.4

Zonisamide, new antiepileptic drug, was administered to 47 epileptic patients to evaluate the efficacy and side effects. The mean duration of administration was 155.04 ±43.98 days. The mean number of combined antiepileptic drugs was 1.23±1.03. The efficacy of zonisamide was rated excellent in 46.8% of all cases, good in 36.2%, fair in 8.5%, and no change in 8.5%. In the 35 case of epiletifom pattern, seizure frequency was improved in 91.4%. The mean value of plasma concentrations was 21.60 ±12.69㎍/ml and showed positive correlation with the dosage. Side effects, such as anorexia, headache, dizziness, weight loss and hypersomnia, occured in 46.9% of the patients. In most side effects they occured in the initial phase of treatment, were reversible, and when the treatment was combined with other antiepileptic drugs. Zonisamide was discontinued in 34.7% ; 14.3% were due to poor compliance of the patients, 12.2% due to above mentioned side effects, 4.1% due to uncontrolled seizure, 4.1%, due to other medical illness.

혈액투석환자와 신장이식수술 환자에서 불안, 우울, 생활만족도에 대한 비교 연구

김명재,장환일,임옥근 大韓神經精神醫學會 1993 신경정신의학 Vol.32 No.5

It has been known that patients on hemodialysis have many psychological problems ; such as anxiety, depression, or life dissatisfaction. We compared the levels of anxiety, depression, and life satisfaction between the patients on hemodialysis and the patients with kidney transplantation. The authors surveyed 44 patients under hemodialysis treatment and 74 patients with kidney transplants at Kyung Hee Medical Center from September 1992 to January 1993. Anxiety, depression, and life satisfaction were evaluated with The State-Trait Anxiety Inventory, Beck Depression Inventory, and Life Satisfaction Scales. And the following results were obtained : 1) There was no significant difference in anxiety between two groups. 2) The hemodialysis group was significantly more depressed than the kidney tranplantation group. 3) The kidney transplantation group reported significantly higher levels of satisfaction, especially with health and sexual life, than the hemodialysis group. From these results, authors suggest that kidney transplantation may improve overall life satisfaction, especially with health and sex, and may alleviate depression in the patients on hemodialysis. Further study will be necessary to understand the direct psychological effects of kidney transplantation on the patients who are on hemodialysis.

국내 연구논문의 키워드 네트워크 분석을 통한 수소충전소 연구개발 동향

임옥근(Ohk Kun Lim) 한국화재소방학회 2021 한국화재소방학회논문지 Vol.35 No.4

전세계적인 기후변화는 기존에는 겪어보지 못했던 자연재난과 같이 예상치 못한 심각한 피해를 발생시키고 있으며, 이로 인해 친환경에너지인 수소 사용에 대한 관심이 증가하고 있다. 국내에서는 수소자동차 보급과 함께 수소충전소와 같은 인프라 구축이 최근 활발하게 이루어지고 있으나 텍스트 마이닝을 활용한 관련 연구동향에 대한 체계적인 분석은 이루어지지 않았다. 본 논문에서는 최근 10년간 한국학술진흥재단 등재지에 게재된 수소충전소 관련논문들에서 텍스트 마이닝기법을 사용하여 기간별 주요 키워드와 연구주제들을 분석했다. 2017년 이후로 수소충전소, 연료전지, 전기충전소 등이 핵심키워드로 등장했으며 수소저장, 수소자동차, 수소충전소 안전관련 주제들의 연구비중이 증가하고 있음을 확인할 수 있었다. 이런 정량적인 분석결과는 국내 수소인프라의 효율적인 구축을 위한 연구와 정책방향 수립에 활용될 수 있을 것이다. Global climate change has caused various natural disasters, which has resulted in serious damage to the society. Therefore,there has been a growing interest in utilizing eco-friendly energy sources such as hydrogen fuel. Hydrogen vehicles andinfrastructures have been studied extensively. However, the research trends of hydrogen refueling stations have not beensystematically analyzed using text mining with domestic research articles. The keyword network and research topics wereanalyzed based on the Korea Citation Index (KCI) data of the past 10 years. The analysis revealed that “hydrogen refuelingstation,” “fuel cell,” and “charging station” are new research keywords. Furthermore, topics such as “hydrogen storage,”“hydrogen and electric vehicle,” and “safety in hydrogen refueling station” are becoming increasingly popular. Thesequantitative analysis results provide an insight on the development of hydrogen infrastructure and research policy.