检索结果-南通市图书馆

GENUS MINIMIZING IN SYMPLECTIC 4-MANIFOLDS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2000年第1期21卷 115-120页

作者： cho yongSEUNG cho MISUNG Department of Mathematics Ewha Women’s University Seoul Korea

The authors show that a symplectically embedded surface in a symplectic 4-manifold with hi greater than one minimizes genus in its homology class.

关键词： Generalized Thom Conjecture Seiberg-Witten invariant Symplectic 4-manifolds

Damage and penetration behavior of aluminum foam at various impacts

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2014年第9期21卷 3442-3448页

作者： cho Hosun cho Jaeung Division of Mechanical Engineering Graduate School Kongju National University Division of Mechanical and Automotive Engineering Kongju National University

In this work, the damage and penetration behavior of aluminum foam at various types of impact were examined through experiments. The impact energy of a striker was applied on the fixed aluminum foam having a thickness of 25 mm while increasing its impact by 2 J at each strike from 6 J to 16 J. The results show that the impact energies from 6 J to 12 J could not penetrate aluminum foam. However, the aluminum foam applied with the impact energy of 12 J incurred severe damages on its lower part. Finally, the aluminum foam applied with the impact energy of 14 J was penetrated. The striker having the impact energy of 6 J could penetrate aluminum foam around 10 mm. At this moment, aluminum foam could absorb the impact energy of around 9 J. When the impact energy of 14 J was applied on the aluminum foam, the aluminum foam was penetrated and it absorbed the impact energy of around 17.2 J. It is possible to create the safer structure against impact using the results of this work. The simulation results for the verification of the experimental results imply that the results for all the experiments in this work are reliable. It is possible to predict the structural safety of the aluminum foam for an impact if the impact behavior of aluminum foam performed in this work is utilized.

关键词： aluminum foam absorbed energy finite element analysis impact energy impact load

Flexible highly-effective energy harvester via crystallographic and computational control of nanointerfacial morphotropic piezoelectric thin film

在线全文

学校读者我要写书评

暂无评论

Nano Research 2017年第2期10卷 437-455页

作者： Chang Kyu Jeong Sung Beom cho Jae Hyun Han Dae yong Park Suyoung Yang Kwi-II Park Jungho Ryu Hoon Sohn yong-Chae Chung Keon Jae Lee Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea KAISTInstitute for the NanoCentury (KINC) 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea Division of Materials Science and Engineering Hanyang University 222 Wangsimni-ro Seongdong-gu Seou104763 Republic of Korea Department of Civil and Environmental Engineering KAIST 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea Department of Energy Engineering Gyeongnam National University of Science and Technology 33 Dongjin-ro Jinju Gyeongnam 52725 Republic of Korea Functional Ceramic Group Korea Institute of Materials Science (KIMS) 797 Changwon-daero Seongsan-gu Changwon Gyeongnam.51508 Republic of Korea

Controlling the properties of piezoelectric thin films is a key aspect for designing highly efficient flexible electromechanical devices. In this stud）~ the crystallographic phenomena of PbZr1-xTixO3 （PZT） thin films caused by distinguished interfacial effects are deeply investigated by overlooking views, including not only an experimental demonstration but also ab initio modeling. The polymorphic phase balance and crystallinity, as well as the crystal orientation of PZT thin films at the morphotropic phase boundary （MPB）, can be stably modulated using interfacial crystal structures. Here, interactions with MgO stabilize the PZT crystallographic system well and induce the texturing influences, while the PZT film remains quasi-stable on a conventional A1203 wafer. On the basis of this fundamental understanding, a high-output flexible energy harvester is developed using the controlled-PZT system, which shows significantly higher performance than the unmodified PZT generator. The voltage, current, and power densities are improved by 556%, 503%, and 822%, respectively, in comparison with the previous flexional single-crystalline piezoelectric device. Finally, the improved flexible generator is applied to harvest tiny vibrational energy from a real traffic system, and it is used to operate a commercial electronic unit. These results clearly indicate that atomic-scale designs can produce significant impacts on macroscopic applications.

关键词： energy harvesting morphotropic phaseboundary (MPB) piezoelectric first-principles calculation lead zirconium titanate(PZT)

On-screen fingerprint sensor with optically and electrically tailored transparent electrode patterns for use on high-resolution mobile displays

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2020年第1期6卷 243-254页

作者： Hyun-Joon Kim-Lee Seog Woo Hong Dong kyun Kim Jinmyoung Kim Hong Suk Kim Seok-Whan Chung Eun-Hyoung cho Hae-Sung Kim Byung-Kyu Lee Device Research Center Samsung Advanced Institute of Technology130 Samsung-roYeongtong-guSuwon-siGyeonggi-do 443-803Republic of Korea

In this study,a mutual capacitive-type on-screen fingerprint sensor,which can recognize fingerprints on a display screen to provide smartphones with full-screen displays with a minimal bezel area,is ***-screen fingerprint sensors are fabricated using an indium tin oxide transparent conductor with a sheet resistance of~10Ω/*** a transmittance of~94%(~86% with the substrate effect)in the visible wavelength range,and assembled onto a display *** at this high transmittance,the electrodes can degrade the display quality when they are placed on the *** interference between periodic display pixel arrays and sensor patterns can lead to the *** is necessary to find an appropriate sensor pattern that minimizes the Moirepattern,while maintaining the signal *** search for appropriate patterns,a numerical calculation is carried out over wide ranges of pitches and rotation *** range is narrowed for an experimental evaluation,which is used to finally determine the sensor *** the selected sensor pitches are too small to detect capacitance variations,three unit patterns are electrically connected to obtain a unit block generating a larger *** applying the selected sensor pattern and circuit driving by block,fingerprint sensing on a display is demonstrated with a prototype built on a commercial smartphone.

关键词： transparent pattern smart

A time-domain estimation method of rapidly time-varying channels for OFDM-based LTE-R systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Digital Communications and Networks 2019年第2期5卷 94-101页

作者： Jin-Kyu choi Van Due Nguyen Hai Nam Nguyen Van Vinh Duong Tien Hoa Nguyen Hanbyeog cho Hyun-kyun choi Seong-Gyoon Park Smart Mobility Research Department of ETR1 DaejeonSouth Korea School of Electronics and Telecommunicalions HUSTViet Nam Electronics and Telecommunications Research Institute DaejeonSouth Korea School of Information and Communication in KongJu National University South Korea

This paper addresses the performance of fast doubly selective fading channel estimation combined with InterCarrier Interference (ICI) cancellation for Long Term Evolution (LTE) communication platform in the High Speed Railway (HSR) environment. We consider the Channel Impulse Response (CIR) coefficients with a critical Doppler frequency shift and multi-path fading that were taken from the WINNER II channel model and the D2a propagation scenario, where the conditions of HSR are analyzed. As multi-path fading increases and the channel varies in the order of the symbol period, we first propose a novel approach for designing a pilot symbol structure in the time domain. Then, we describe the deployment of the proposed pilot symbol structure to estimate the channel in the time domain. Channel information corresponding to the data positions is obtained by linear interpolation. In each OFDM symbol, the slope and the initial value for establishing an interpolation function are estimated to adapt to the time variation of the channel. An accurate estimate of channel state information is used for the purpose of ICI cancellation. The simulation results show that the channel estimated by our proposed method can follow the real channel well, even in a very high Doppler frequency. The estimation method in terms of Mean Squared Error (MSE) significantly outperforms the state-of-the-art methods. The combination of our channel estimator with several interference cancelers provides a considerably better system performance than that achieved when frequency channel estimation is used.

关键词： ICI cancellation OFDM Channel estimation LTE-R

Predicting tumor response after preoperative chemoradiation using clinical parameters in rectal cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第48期17卷 5310-5316页

作者： Chan Ho Park Hee Cheol Kim yong Beom cho Seong Hyeon Yun Woo yong Lee Young Suk Park Doo Ho choi Ho-kyung Chun Departmentof Surgery Samsung Medical Center Sungkyunkwan Univer-sity School of Medicine Irwon-dong 50 Gangnam-gu Seoul135-710 South Korea Division of Hematology-Oncology Depart-ment of Medicine Samsung Medical Center Sungkyunkwan University School of Medicine Irwon-dong 50 Gangnam-guSeoul 135-710 South Korea Department of Radiation Oncology SamsungMedical Center Sungkyunkwan University School of MedicineIrwon-dong 50 Gangnam-gu Seoul 135-710 South Korea

AIM: To evaluate the clinical parameters and identify a better method of predicting pathological complete response (pCR). METHODS: We enrolled 249 patients from a database of 544 consecutive rectal cancer patients who underwent surgical resection after preoperative chemoradiation therapy (PCRT). A retrospective review of morphological characteristics was then performed to collect data regarding rectal examination findings. A scoring model to predict pCR was then created. To validate the ability of the scoring model to predict complete ***: Seventy patients (12.9%) achieved a pCR. A multivariate analysis found that pre-CRT movability (P = 0.024), post-CRT size (P = 0.018), post-CRT morphology (P = 0.023), and gross change (P = 0.009) were independent predictors of pCR. The accuracy of the scoring model was 76.8% for predicting pCR with the threshold set at 4.5. In the validation set, the accuracy was 86.7%. CONCLUSION: Gross changes and morphological findings are important predictors of pathological response. Accordingly, PCRT response is best predicted by a combination of clinical, laboratory and metabolic information.

关键词： Rectal cancer Preoperative chemoradiotherapy Downstaging Tumor regression Validation

Adult intussusception caused by colonic anisakis: A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2019年第17期7卷 2536-2541页

作者： Youn I choi Dong kyun Park Hyun Yee cho Seung Joon choi Jun-Won Chung kyung Oh Kim Kwang An Kwon Yoon Jae Kim Department of Gastroenterology Gachon UniversityGil Medical CenterIncheon 21565South Korea Department of Pathology Gachon University Gil Medical CenterIncheon 21565South Korea

BACKGROUND Colo-colonic intussusception is an uncommon phenomenon in an *** intussusception accounts for < 5% of total cases,and the colo-colonic type is < 30% of *** surgical management has been the treatment of choi... 详细信息

BACKGROUND Colo-colonic intussusception is an uncommon phenomenon in an *** intussusception accounts for choice for intestinal intussusception in adults,because most frequent causes for adult intussusception are malignant in origin,the importance of the roles of preoperative colonoscopic evaluation has recently been *** SUMMARY We report an extremely rare case of adult colo-colonic intussusception caused by colonic anisakiasis and successfully treated by endoscopic removal of the Anisakis body.A 59-year-old man visited the emergency department due to 1 day of lower abdominal colicky *** computed tomography (APCT) revealed the presence of mid-transverse colon intussusception without definite necrosis,which was possibly related with colorectal *** there was no evidence of necrosis at the intussusception site,a colonoscopy was performed to target the colonic lesion and obtain tissue for a histopathological *** Anisakis body was found when inspecting the suspicious colonic lesion recorded by *** Anisakis body was removed with forceps assisted by *** patient’s symptoms improved dramatically after removing the Anisakis.A reduced colon without any pathological findings was seen on the follow-up *** any further treatment,the patient was discharged 5 d after the *** When colonic intussusception without necrosis occurs in an adult,physician should consider a colonoscopy to exclude causes cured by endoscopy.

关键词： Intussusception Anisakis Colonoscopy Case report

Weekend and nighttime effect on the prognosis of peptic ulcer bleeding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2012年第27期18卷 3578-3584页

作者： Young Hoon Youn yong Jin Park Jae Hak Kim Tae Joo Jeon Jae Hee cho Hyojin Park Department of Internal Medicine Gangnam Severance HospitalYonsei University College of MedicineSeoul 135-720South Korea Department of Internal Medicine Dongguk University Ilsan HospitalDongguk University College of MedicineGyeonggi-do 410-773South Korea Department of Internal Medicine Inje University Sanggye Paik HospitalInje University College of MedicineSeoul 139-707South Korea Department of Internal Medicine Kwandong University Myungji HospitalKwandong University College of MedicineGyeonggi-do 412-270South Korea

AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early ***:Retrospective data collection from four referral centers,all of which had a formal out-of-hours emergency endoscopy service,even at weekends.A total of 388 patients with bleeding peptic ulcers who were admitted via the emergency room between January 2007 and December 2009 were *** parameters included time from patients' arrival until endoscopy,mortality,rebleeding,need for surgery and length of hospital ***:The weekday and weekend admission groups comprised 326 and 62 patients,*** were no significant differences in baseline characteristics between the two groups,except for younger age in the weekend *** patients (97%) had undergone early endoscopy,which resulted in a low mortality rate regardless of point of presentation (1.8% overall vs 1.6% on the weekend).The only outcome that was worse in the weekend group was a higher rate of rebleeding (12% vs 21%,P = 0.030).However,multivariate analysis revealed nighttime admission and a high Rockall score (≥ 6) as significant independent risk factors for rebleeding,rather than weekend ***:Early endoscopy for peptic ulcer bleeding can prevent the weekend effect,and nighttime admission was identified as a novel risk factor for rebleeding,namely the nighttime effect.

关键词： Early endoscopy Nighttime effect Pepticulcer bleeding Rebleeding Weekend effect

Simultaneous determination of fourteen components of Gumiganghwal-tang tablet in human plasma by UPLC-ESI-MS/MS and its application to pharmacokinetic study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2021年第4期11卷 444-457页

作者： Seung-Hyun Jeong Ji-Hun Jang Guk-Yeo Lee Seung-Jung Yang Hea-Young cho yong-Bok Lee College of Pharmacy Chonnam National University77 Yongbong-roBuk-guGwangju61186Republic of Korea National Development Institute of Korean Medicine 288 Udeuraendeu-gilAnyang-myeonJangheung-gunJeollanam-do59338Republic of Korea Department of Oriental Rehabilitation Medicine Dongshin University Gwangju Korean Medicine Hospital141 Wolsan-roNam-guGwangju61619Republic of Korea College of Pharmacy CHA University335 Pangyo-roBundang-guSeongnam-siGyeonggi-do13488Republic of Korea

Gumiganghwal-tang is a traditional herbal medicine widely used for its anti-inflammatory,analgesic,and antipyretic ***,the safety and efficacy of its active ingredients based on an in vivo pharmacokinetic(PK)study have yet been *** have established a sensitive and accurate UPLC-ESI-MS/MS method and conducted a PK study on 14 constituents of Gumiganghwal-tang through human plasma *** conditions were optimized according to the physicochemical properties of the 14 compounds to facilitate efficient separation and eliminate overlap or interference between ***-C18 and Inertsil-C8 columns were used as UPLC stationary phases,and acetonitrile and aqueous formic acid were used as mobile *** the analytes were quantified with a triple quadrupole mass spectrometer using electrospray ionization in multiple reaction monitoring *** chromatograms of 14 bioactive compounds showed excellent elution and sensitivity,and each peak was selectively separated and quantified without interference with each other or *** established analytical method was based on international guidelines and was successfully used to perform PK studies of 14 herbal ingredients in humans after oral administration with Gumiganghwal-tang *** oral absorption of most active components of Gumiganghwal-tang was relatively rapid and remained considerably long in the body to be quantified in plasma up to 48 h after administration.

关键词： Gumiganghwal-tang Fourteen bioactive ingredients Simultaneous analysis UPLC-ESI-MS/MS Pharmacokinetics Clinical study