The stone pagoda continued to be damaged by weathering and corrosion over time, and natural disasters such as earthquake are accelerating the destruction of cultural properties. Stone pagoda has discontinuous structure behavior and is very vulnerable to the seismic load acting in lateral direction. It is necessary to analyze various design variables as the contact surface characteristics play an important role in the dynamic behavior of stone pagodas. For this purpose, contact surface characteristics of stone pagoda can be classified according to surface roughness and filler type, and representative model is selected and structural modeling and analysis are performed using the discrete element method. Also, the seismic load according to the repetition period is calculated and the dynamic analysis is performed considering the discontinuous characteristics of the stone pagoda. Finally, the seismic behavior characteristics can be analyzed by the evaluation of stresses, displacements and structural safety.

The ship steering is a very important factor for safe operation. Recently, the ship is controlled in a space other than the wheelhouse through the wired controller. However, there has been a continuing need to improve the inconvenience of wired systems. In this study, a system to control the steering angle and throttle of ship by RF communication method was developed and applied to actual ship. Since the reliability is secured through the safety evaluation, the wireless steering system improves the convenience and economic efficiency of ship steering.

Ameloblastoma is an odontogenic tumor characterized by various sites of metastasis, malignant transformation, and a high recurrence rate over time. Ameloblastic carcinoma(AC) is the term reserved for an ameloblastoma with histologic evidence of malignancy in the primary tumor. AC is classified into two types: most ACs occur de novo, and only few cases of malignant transformation of ameloblastoma become apparent. Here, we report a case of AC, arising from recurrent acanthomatous ameloblastoma on the maxillary sinus, in a 60-year-old male patient. The mass was first diagnosed as acanthomatous ameloblastoma; subsequently, surgical curettage was performed thrice while partial maxillectomy was performed twice. On the fifth recurrence, the tumor was identified as AC.

Pseudosarcomatous fibromatosis (PSF), also known as nodular fasciitis and pseudosarcomatous fasciitis, is a rare, benign proliferation of fibroblasts and myofibroblasts. It is often misdiagnosed as sarcoma because of its characteristic rapid progression, leading to unnecessary and aggressive surgery. Here we report a case of PSF found in the masseter muscle in a 26-year-old female. The mass that could be misdiagnosed because of its rapid growth characteristics was surgically excised by an intraoral approach and diagnosed as PSF by histopathologic examinations.

이 연구에서는 입력변수의 확률분포로부터 비선형 구조응답의 확률분포 추정방법을 제안한다. 응답함수를 확률변수들의 평균점과 응답의 꼬리부분 상위 0.01%값에 기여하는 확률변수조합에서 각각 1차 테일러급수로 근사한다. 두 응답함수에 대해 모멘트법을 적용한 후 이를 가우시안 분포로 추정한다. 추정된 두 분포를 결합하기 위해 연결함수를 도입하고, 분포의 연속조건을 적용하여 연결함수의 미정계수를 결정한다. 제안된 방법을 케이블 교량 예제에 적용하고, 카이제곱 검증을 이용하여 추정된 분포의 적합성을 확인한다. 기존의 모멘트법과 제안된 방법의 결과를 비교, 분석한다.

In this study, we measured the concentration of total volatile organic compounds (TVOCs) in four different seasons from 2016 to 2017 in order to determine seasonal variation of indoor air quality in relation to public transportation modes (subways, trains, and express buses). The measurement was carried out both during rush hour when traffic was congested as well as during non-rush hour when traffic was not congested. Effects by season, degree of congestion, and characteristics of public transportation were analyzed on the basis of 295 items of data during the periods of congestion and 295 items of data during the periods of non-congestion. The average TVOCs concentration in winter was the highest with 226.4 μg/m 3 . The average TVOCs concentration on an express bus was the highest with a seasonal average of 142.3 μg/m 3 . The TVOCs concentration in the period of congested traffic was higher than in the period of non-congested traffic for all public transportation modes. For the average TVOCs concentration by season and transportation, there was no data that exceeded the guidelines regarding maintaining indoor air quality. However, 2.5% of all sample measured data (TVOCs) exceeded the guidelines regarding maintaining indoor air quality. Therefore, the continuous monitoring of public transport vehicles is required.

배경/목적: 한국의 내시경적 역행성 담췌관 조영술(ERCP)의 질을 평가한 전국적인 실태 조사 결과를 표준 질지표와 비교하여 기술하고자 한다. 방법: 건강보험심사평가원의 자료를 분석하였고, 이후에 무기명으로 전국적인 설문 조사를 시행하였다. 결과: ERCP 의사 157명 중에서 129명이 설문에 응답하여 82.2%의 회수율을 보였다. 한국에서 ERCP 시행률은 지속적으로 증가하였다. 약 반수의 의사는 1인당 ERCP 양이 연간 200예 이상으로 시술량이 많은 ERCP 의사에 속하였다. 대부분의 ERCP 의사들은 1단계의 ERCP 시술을 시행하였으나 담췌관 내압 측정, 담관-췌관경 및 췌장 시술은 많은 양의 시술을 하는 병원에서만 시행하였다. 대부분의 ERCP 의사들은 90% 이상의 성공률을 보였으나, 예비 괄약근 절개율이 약 25%로 표준 질지표보다 높았다. 12명의 ERCP 의사들이 최근 1년간 ERCP 후 환자가 사망하는 합병증을 경험하였다. 또한 ERCP 수련과 시술량이 낮거나 중등도인 병원의 방사선 차폐는 표준 질지표에 도달하지 못하였다. 결론: 한국의 ERCP 술기는 표준적인 질지표를 충족하였으나, ERCP 수련과 방사선 차폐 문제는 향후 개선이 필요하다.

In this study, the condition of the hazardous materials in the bus was monitored according to the ventilation mode of the air conditioning system during bus service. The bus was surveyed using the indoor air quality measurement method of public transportation vehicles within one year of delivery. We evaluate the CO2 and PM10, which are the controlled parameters in buses by the Ministry of Environment, and VOCs and HCHO, the non-controlled parameters. The PM10 concentration increased due to outdoor air intake; however the CO2 concentration was found to decrease. In addition, the concentration of VOCs and HCHO was found to decrease due to the forced ventilation system and the outdoor air intake. These results show that the concentration of the other materials except PM10 can be changed due to the outside air concentration and forced ventilation system. Therefore, through indoor air quality characteristics of the bus according to air condition system are intended to be used as the basis of an operation manual.

This study describes the effects of palm oil biodiesel (PD) blended with diesel on the combustion performance, emission characteristics and soot morphology in a 4-cylinder CRDI diesel engine. 5 kinds of fuels are used with blending as diesel/biodiesel volume ratio 0%, 10%, 20%, 30%, 100%. The engine is operated under idle speed, 750rpm and load conditions of the engine are 0 Nm and 40Nm. The Coefficient of Variation(COV) of Indicated Mean Effective Pressure(IMEP) shows that the engine operates very steadily in the idle state. But fuel consumption is increased. And Emission results show that the oxygen in biodiesel has a great influence on the production of exhaust emissions. The nitrogen oxides(NOx) is decreased because of high viscosity and low heating values of biodiesel at low blend ratio. But NOx and Carbon monoxide(CO) are increased above a certain blend ratio. Particulate matter(PM) and Hydrocarbons(HC) is decreased according to increase of blend ratio. The size of soot is decreased and the morphology of soot is developed to cluster with increasing blend ratio.

Nanoparticles of PbTe are prepared via chemical reaction of the equimolar aqueous solutions of Pb(CH3COO)2 and Te at 120°C. The size of the obtained particles is 100 nm after calcination in a hydrogen atmosphere. Dense specimens for the thermoelectric characterization are produced by spark plasma sintering of prepared powders at 400°C to 500°C under 80 MPa for 5 min. The relative densities of the prepared specimens reach approximately 97% and are identified as cubic based on X-ray diffraction analyses. The thermoelectric properties are evaluated between 100°C and 300°C via electrical conductivity, Seebeck coefficient, and thermal conductivity. Compared with PbTe ingot, the reduction of the thermal conductivities by more than 30% is verified via phonon scattering at the grain boundaries, which thus contributes to the increase in the figure of merit.

저자들은 3년 전 폐선암으로 수술과 수술 후 보조항암요법을 시행한 뒤 경과관찰 중인 환자에게 췌장내 단일 고형 종괴가 발생한 것을 확인하고 수술적 치료를 시행하였다. 수술 후 조직검사 결과, 췌장의 단일 고형 종괴는 폐선암의 재발인 것으로 확진되었기에 문헌고찰과 함께 보고하는 바이다.

This study investigates the indoor air quality conditions of the total of 52 buses depend on seasons, time and others. We evaluated the CO₂and PM10, the controlled parameters in express buses by Ministry of Environment and VOCs and HCHO, the non-controlled parameters. The CO₂concentration during peak commute times was 38.5% in summer and 15.4% in autumn, which are higher than the normal. But, PM10 concentration was influenced by the outside air not number of passengers. The concentration of VOCs were not related with other parameters such as number of passengers, seasons, and driving time. And then, the formaldehyde concentration was not related with seasons as it showed little difference between summer and autumn.