슈퍼커패시터를 적용한 에너지 저장시스템 설계에 관한 연구 (The Research On the Energy Storage System Using SuperCapacitor)
-
- 예술인문사회 융합 멀티미디어 논문지
- /
- 제8권11호
- /
- pp.215-222
- /
- 2018
본 논문에서는 슈퍼커패시터를 적용한 에너지 저장장치에 대해서 연구하였다. 납축전지등을 사용하였던 기존방식과는 다르게 슈퍼커패시터를 사용하여 고출력을 달성할 수 있으며, 이러한 특징으로 인하여 연구된 저장장치는 비상전원용 전력을 공급할 수 있을 뿐만 아니라, 전력품질 개선이나 짧은 순간에 큰 출력을 요구하는 고속 기동용 모터등의 전원시스템으로도 사용이 가능한 장점이 있다. 에너지변환 시스템은 양방향 인버터와 컨버터로 구성되어 고속, 고출력의 충전, 방전을 수행할 수 있는 장점도 있다. 양방향 인버터를 이용한 two loop 제어기 설계 방법이 제시되었고, 실험과 제작을 통해 설계 방법의 정합성을 입증하였다. 설계 순서는 먼저 상태공간 평균화 기법과 Decoupling 기법을 이용하여 선형화된 전달함수를 계산하였다. 다음 20% 오버슈트와 안정시간을 만족시키는 전류 제어기 설계를 한 후에 오버슈트 없는 전압과 10배 이상 느린 안정시간을 가지는 전압제어기를 설계한 후 단위계단응답 커브를 통해 원하는 설계특성이 나오는 지를 확인하는 과정으로 이루어진다. 설계된 제어기들은 계통과 단위 역률을 이루며 제어되기 때문에 전력품질 향상을 이룰 수 있으며, 빠른 응답특성과 정상상태 오차를 0으로 만들 수 있는 우수한 제어특성을 가지고 있음을 확인할 수 있었다.
최근 다양한 증례 보고에서 소개되고 있는 jaw motion tracking은 환자의 안궁 이전 및 개별화된 하악 운동 경로를 기록한 후, 이를 computer-aided-design/computer-aided-manufacturing (CAD-CAM) 소프트웨어의 가상공간상에 재현하는 방법이다. 본 증례의 환자는 오랜 기간 구치부의 상실로 인해 교합평면의 붕괴가 관찰되었기에, 수직 교합 고경의 증가를 동반한 완전 구강 회복술을 계획하였다. 우선 jaw motion tracking을 진행하여 새로운 중심위 상에서 환자의 하악 운동을 기록한 후, 이 정보를 환자의 초진 구내 데이터 및 3차원 안면 스캔 데이터와 조합하여 가상 환자를 생성하였다. 가상 환자 상에서 진행한 디지털 왁스업과 임플란트 식립 계획을 바탕으로 임시 보철물을 제작하였다. 새롭게 설정된 수직 교합 고경 상에서 적절한 견치 유도를 보이는 임시 보철물의 검증을 통해, 최종 보철물로 이행하였다. 이처럼 디지털 치의학 기술의 장점을 활용하여 환자는 저작능과 심미성의 개선에 만족하였기에 본 증례를 보고하고자 한다.
Objective: Computed tomography (CT) is an established method for the diagnosis, staging, and treatment of multiple myeloma. Here, we investigated the potential of photon-counting detector computed tomography (PCD-CT) in terms of image quality, diagnostic confidence, and radiation dose compared with energy-integrating detector CT (EID-CT). Materials and Methods: In this prospective study, patients with known multiple myeloma underwent clinically indicated whole-body PCD-CT. The image quality of PCD-CT was assessed qualitatively by three independent radiologists for overall image quality, edge sharpness, image noise, lesion conspicuity, and diagnostic confidence using a 5-point Likert scale (5 = excellent), and quantitatively for signal homogeneity using the coefficient of variation (CV) of Hounsfield Units (HU) values and modulation transfer function (MTF) via the full width at half maximum (FWHM) in the frequency space. The results were compared with those of the current clinical standard EID-CT protocols as controls. Additionally, the radiation dose (CTDIvol) was determined. Results: We enrolled 35 patients with multiple myeloma (mean age 69.8 ± 9.1 years; 18 [51%] males). Qualitative image analysis revealed superior scores (median [interquartile range]) for PCD-CT regarding overall image quality (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), edge sharpness (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), image noise (4.0 [4.0-4.0] vs. 3.0 [3.0-4.0]), lesion conspicuity (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), and diagnostic confidence (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]) compared with EID-CT (P ≤ 0.004). In quantitative image analyses, PCD-CT compared with EID-CT revealed a substantially lower FWHM (2.89 vs. 25.68 cy/pixel) and a significantly more homogeneous signal (mean CV ± standard deviation [SD], 0.99 ± 0.65 vs. 1.66 ± 0.5; P < 0.001) at a significantly lower radiation dose (mean CTDIvol ± SD, 3.33 ± 0.82 vs. 7.19 ± 3.57 mGy; P < 0.001). Conclusion: Whole-body PCD-CT provides significantly higher subjective and objective image quality at significantly reduced radiation doses than the current clinical standard EID-CT protocols, along with readily available multi-spectral data, facilitating the potential for further advanced post-processing.
졸-겔(sol-gel) 방법을 이용하여 스피넬(spinel) 구조를 가지는
This dissertation is presented in two major parts. The first part presented in Chapter 3 attempts to verify the major hypothesis of the present study that the research and development laboratories(hereafter referred to R&D laboratories), establishd withine industrial firms to develop new technologies needed for their own industrial activities, may have another but very important functions to bring information on the externally generated technologies to attention of their respective management decision makers, eventually resulting in the transfer of technology; and such information functions of the R&D laboratories may be better performed by well-organised laboratories than by poorly-organised ones. The second part presented in Chapters 4, 5, 6 and 7 discusses, after the preceding hypotheses has been verified, some desirable situations of the R&D laboratories in facilitating the flow of information on new technologies developed in the world into their industrial firms, centering on the organisational positions and the major fields of interest of the person in charge of the R&D centers, services of the library and technological information office supporting the R&D laboratories, and frequencies of direct contacts of research and development workers with experts in the world and of participation in various conferences, seminars, workshops, exhibitions, etc. Now that there is no recognised instrument and method available for direct measurement of volume of technological information transfered into a particular industrial firm, the number of technologies introduced into a given firm is employed in the present study as an analogous parametre indicating volume of technological information transfered into the firm during a particular period of time. A logical attempt to justify the use of the indirect paramentre is made in Chapter two. vidences needed to verify the hypotheses of the present study are collected through the various publications of the Korea Industrial Research Institutes and other agencies and institutions related to industrial research activities, and through responses to the questionnaire posted to a sample of the 66 R&D laboratories on 6 May 1987 and returned by 30 August of the same year. Some findings and conclusions made in the study are summarised as follows: (1) More information on externally developed technologies flows into the industrial firm with a R&D laboratory of its own than into the industrial firm without one, and naturally, more chances of transfer of technologies are given to the former than to the latter (see 3. 2) (2) After establishing an R&D laboratory, more technological information flows into the industrial firm than before establishing one (see 3. 3) (3) More technological information flows into the industrial firm with a well-organised R&D laboraory than into the firm with a poorly-organised one (see 3. 4) (4) More technological information flows into the ndustrial firm where the director of its R&D laboratory has status qualified to participate in the highest managerial decision making processes of the firm than into the industrial firm where the director does not have such status (see 4. 2) (5) More technological information flows into the industrial firm where the director of R&D laboratory does not hold other positions within the firm than into the industrial firm where the director holds other positions (see 4.3) (6) There is evidence showing that quantities of technological information transfered into industriali firms vary with the case that the major background of the director of the R&D laboratory is the same as the main field of R&D activities of his or her laboratery, the case that the director's background is partly related to the field of R&D activities of the laboratory, and the case that the director's major background is different from the field of R&D activities of the laboratory (see 4.4) (7) More technological information flows into the industrial firm with the director of its R&D laboratory appointed from among professional research and development workers than into the industrial firm with the director of its R&D laboratory appointed from among general managers (see 4.5) (8) More technological information flows into the industrial firm with its R&D laboratory which has established a library service unit within its own jurisdiction than into the industrial firm with its R&D laboratory which has established a library service unit within its own jurisdiction than into the industrial firm with its R&D laboratory which uses a library within the firm but outside the laboratory (see 5. 1) (9) More echnological information flows into the industrial firm with a technological information office of its own than into the industrial firm without such an office (see 5. 2) (10) More technological information flows into the industrial firm with a large research and development staff in its R&D laboratory than into the industrial firm with a small staff in its R&D laboratory (see 5. 2) (11) More technological information flows into the industrial firm with its R&D laboratory whose staff members more frequently contact experts in the conferences, seminars, symposiums, and workshops held in foreign countries and novelties in the world's major exhibitions than into the industrial firm with its R&D laboratory whose staff members less frequently contact such experts and novelties (see 6. 2 ; 6. 3)
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
체외수정 시술을 위해 중앙대학교부속병원 산부인과학 교실 불임크리닉을 방문한 환자중 1993년 3월부터 1994년 8월까지 난관폐쇄로 인하여 불임이 된 환자 113명(119주기)을 대상으로 GnRH-a 병합요법 중 Short protocol 방법으로 과배란시 임신된 45명(47주기)과 임신이 되지 않은 68명(72주기)에서 hCG 투여 당일 혈청내 E2 및 P4 수치를 측정하여 임신의 결과를 비교하였다. 1. 환자의 평균 연령 및 불임기간은 임신군에서
배경:종양억제 유전자인 p53은 폐암을 비롯하여 인체에 발생될 수 있는 다양한 종양들에 있어서 가장 빈번히 변이를 일으키는 유전자로 알려져 왔으며, 정상적인 p53은 세포분화 과정 중 G1 arrest 또는 세포자멸을 통하여 세포 성장을 억제한다는 증거들이 발견되고있다. 더불어 유전자 치료에 p53을 사용할 수 있는지에 대해서도 많은 연구가 진행 중이다 대상 및 방법: 이런 p53 단백질의 기능을 이해하기 위한 한 가지 방법으로 정상세포나 종양세포 안에 과량의 p53을 발현시킬 수 있는 p53 표현 중개물(expression vectors)을 이용할 수 있다. 우리는 각기 다른 p53 성질을 지니고 있는 네가지 비소세포폐암 세포를 대상으로 정상적인 p53을 지닌 adenovirus를 이용하여 비소세포폐암에 Adenovirus-p53을 이입시킬 경우 p53 단백질이 증가하는지의 여부와 Adenovirus-p53이 종양세포의 성장에 미치는 영향을 관찰하였으며, p53에 의한 세포 독성에 있어서 세포자멸과의 관련성 여부 및 실험관 안에서 Adenovirus-p53이 비소세포폐암의 종양형성 능력에 미치는 영향을 관찰하였다. 결과: 이번 실험 결과는 다음과 같이 요약될 수 있다. 변이성 p53을 갖고 있거나 p53 유전자가 없는 비소세포폐암 세포는 정상적인 p53을 가지고 있는 종양세포에 비하여 Adenovirus-p53에 의한 세포성장 억제정도가 높았으며, p53을 과발현시킬 경우 세포자멸을 관찰할 수 있었다. 그리고 Adenovirus-p53은 비소세포폐암의 집락 형성 능력을 억제할 수 있고, 또 이미 형성된 집락도 그 성장을 억제할 수 있다는 사실도 확인하였다. 결과: 이번 실험의 결과로 adenovirus는 비소세포폐암 세포에 종양억제유전자를 이입시키는데 매우 효과적인 매개물이며, 특히 p53이 소실되거나, 변이를 일으킨 종양세포들은 Adenovirus-p53에 의하여 쉽게 세포자멸이 유발된다는 사실을 알게 되었다.
본 논문에서는 반복적 구성 기법과 관전류 노출자동조절 기법이 영상의 화질과 방사선량에 미치는 영향을 관상동맥 전산화단층촬영 혈관조영 영상(coronary computed tomography angiography, CCTA)을 대상으로 팬텀 실험에 기반하여 평가하고자 한다. 이를 위하여 미국 의학물리학회(American Association of Physics in Medicine) 표준의 성능 평가 팬텀을 320 다중검출열 CT로써 촬영하였다. 80 kVp, 100 kVp, 120 kVp의 관전압에 있어서, 관전류 노출자동조절 기법은 저선량 목표 표준편차(SD=44)와 고선량(목표 표준편차=33)의 두 가지 설정으로써 촬영하였다. 재구성 변수로서는 필터보정 역투영(FBP)와 반복적 재구성 방법을 설정하여, 전부 12개의 재구성 영상을 획득하였다(12=3 (80, 100, 120 kVp)