http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이음5G 4.7 GHz 대역에서 건물간 전달손실 측정 및 분석
장원,김동우,조병록,오순수 한국전자파학회 2023 한국전자파학회논문지 Vol.34 No.7
A demand-based deployment strategy has been recently proposed for e-Um5G in the industrial market. This study measured the transmission loss between buildings at a frequency of 4.7 GHz to initiate small cell deployment in certain areas. A local average apparatus was utilized to remove fading effects, and data were acquired at discrete points one or two meters apart. The transmission losses for buildings 39 m and 95 m from the transmitter were 56.6 dB and 69.1 dB, respectively, excluding free-space loss. The transmission loss was found to be sensitive to building structure and transmitter location, as the loss for a building 39 m away decreased to 49.5 dB when the transmitter was moved closer to the building entrance. The measured results were analyzed in terms of the ITU-R SG3 (International Telecommunication Union-Radiocommunication Sector, Study Group 3) definition of building entry loss and can be used for frequency sharing and building-level small cell deployment in the e-Um5G frequency band.
장원기,조중구 대한흉부심장혈관외과학회 1999 Journal of Chest Surgery (J Chest Surg) Vol.32 No.11
The pulmonary sarcomatoid carcinoma is a rare malignant tumor, which is composed of an admixture of carcinomatous and sarcomatous components, and accounts for 0.3% of all pulmonary neoplasms. Clinicopathological features are often related to anatomical location: central endobronchial type and peripheral parenchymal type. Noninvasive diagnostic test had a low yield in detection sarcomatoid carcinoma. Metastasis to the regional lymph nodes and to distant organ is common. The prognosis is poor and the median survival is about 15 months. We report two cases of pulmonary sarcomatoid carcinoma with review of literatures.
서로 다른 산을 조절인자로 활용하여 제조한 지르코늄 기반 금속유기골격체의 Diisopropyl Methylphosphonate 흡착 특성
장원형 ( Wonhyeong Jang ),김홍현 ( Honghyun Kim ),정상조 ( Sangjo Jeong ) 한국공업화학회 2021 공업화학 Vol.32 No.5
UiO-66은 높은 흡착능력과 구조적 및 열적 안정성 등으로 여러 현장에 적용 가능한 금속유기골격체(MOF)이다. UiO-66은 제조과정에서 조절인자로 사용되는 산의 종류와 양에 따라 구조적 특성이 변형되고, 화학작용제 흡착 능력을 높일 수 있다고 알려져 있다. 이에 본 연구에서는 다양한 산을 조절인자로 첨가하여 UiO-66을 합성하고, 그 특성을 FT-IR, XRD, 적정장치, 그리고 유사화학작용제 diisopropyl methylphosphonate (DIMP)를 활용한 흡착실험을 통해 분석하였다. 연구 결과 UiO-66의 제조과정에서 염산을 첨가할 시 UiO-66의 Zr-OH 결합과 UiO-66의 유기연결체인 테레프탈산 구조에 일부 손상이 있었다. 특히 이러한 구조 손상은 염산의 농도가 일정 수준 이상으로 높을 때, 그리고 합성시간이 일정 시간 이상으로 길어질 때 발생하였다. 하지만 아세트산과 포름산을 조절인자로 활용하여 제조한 UiO-66은 구조적 손상이 발견되지 않았으며, 염산을 활용하여 제조한 UiO-66에 비하여 결정도, 비표면적, 공극의 부피, 그리고 DIMP 흡착 능력이 모두 높게 나타나 향후 화학작용제 흡착제로서 활용 가능성이 높을 것으로 판단되었다. Depending on the type and amount of acid used as a modulator in the manufacturing process, the structural properties of UiO-66 can be modified and the adsorbability of chemical warfare agents can be enhanced. In this study, several acids as a modulator were used to synthesize UiO-66. Their properties were analyzed with FT-IR, XRD, titrator, and adsorption isotherms using chemical warfare agent simulant, DIMP. The UiO-66, structurally damaged by hydrochloric acid as a modulator, showed lower crystallinity and DIMP adsorption capacity and also smaller specific surface area and volume of voids compared to those of UiO-66, which was manufactured using acetic acid, and formic acid as a modulator. Additionally, UiO-66 which was synthesized by adding formic acid and hydrochloric acid as a modulator, showed the highest DIMP adsorption capacity and is likely to be used as an adsorbent for chemical warfare agent in the future.
CarboMEdics 기계판막을 이용한 심장판막 치환술의 임상 연구
장원기,구자홍,조중구,김공수 대한흉부심장혈관외과학회 2000 Journal of Chest Surgery (J Chest Surg) Vol.33 No.1
Background: The CarboMedics prosthetic heart valve was produced in an attempt to improve the existing valve designs and was especially concerned with easily the implantation and further reduction of turbulence. Precise positioning of the valve in situ was achieved by the abilityof the valve to rotate relative to the sewing ring. Improved monitoring is possible due to increased radiopacity and the dacron sewing ring is coated with carbon to reduce pannus overgrowth. The leaflets have an opening angle of 78 degrees that apparently allows a rapid synchronous closure The aim of this study was to analyze the clinical performance of the CarboMedics valve prostheses(45 mitral 13 aortic and 7 double aortic-mitral valve replacement) were implanted in 65 patients(mean age 48.75$\pm$9.74 years) Result: The operative mortality was 3.1%(2/65) causes of death were low cardiac output syndrome. Total follow up was 1831 patient-months and mean follow up was 29.06$\pm$10.97 months/patient. No structural failure hemorrhage valve thrombosis and late death have been observed. Embolism occurred at a rate of 0.65%/Patient-year. Actuarial survival and thrombo-mbolism free rate at 36 months were 96.9% and 98.4% respectively. Consclusions: The CarboMedics valve stands for low valve related complicatons.