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Optimal three-dimensional impact time guidance with seeker’s field-of-view constraint

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Chinese Journal of Aeronautics 2021年第2期34卷 240-251页

作者： Shaoming HE chang-hun lee Hyo-Sang SHIN Antonios TSOURDOS School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Department of Aerospace Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea School of Aerospace Transport and ManufacturingCranfield UniversityCranfiehMK43 OALUnited Kingdom

This paper proposes a new three-dimensional optimal guidance law for impact time control with seeker’s Field-of-View(FOV) constraint to intercept a stationary target. The proposed guidance law is devised in conjunction with the concept of biased Proportional Navigation Guidance(PNG). The guidance law developed leverages a nonlinear function to ensure the boundedness of velocity lead angle to cater to the seeker’s FOV limit. It is proven that the impact time error is nullified in a finite-time under the proposed method. Additionally, the optimality of the biased command is theoretically analyzed. Numerical simulations confirm the superiority of the proposed method and validate the analytic findings.

关键词： Applied optimal control Field-of-view constraint Impact time control Missile guidance Optimal error dynamics

Classification of hepatobiliary scintigraphy patterns in segmented gallbladder according to anatomical discordance

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World Journal of Clinical Cases 2023年第11期11卷 2423-2434页

作者： Yun-Chae lee Won-Sik Jung chang-hun lee Seong-hun Kim Seung-Ok lee Division of Gastroenterology Department of Internal MedicineJeonbuk National University Medical SchoolJeonju 54907JeonbukSouth Korea Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital Jeonju 54907JeonbukSouth Korea

BACKGROUND Hepatobiliary scintigraphy(HBS)is a useful diagnostic imaging technique that uses radiotracers to evaluate the function of the gallbladder(GB)and biliary *** segmented GB,some HBS images reveal a discordant GB boundary as compared to anatomical *** To evaluate the characteristics of HBS in segmented GB and determine the clinical relevance according to HBS *** A total of 268 patients with chronic cholecystitis,gallstones,or biliary colic symptoms who underwent HBS between 2011 and 2020 were *** GB was defined as segmental luminal narrowing of the GB body on computed tomography(CT)or magnetic resonance(MR)images,and HBS was examined 1 mo before or after CT or *** GB was classified into 3 types based on the filling and emptying patterns of the proximal and distal segments according to the characteristics of HBS images,and GB ejection fraction(GBEF)was identified:Type 1 was defined as a normal filling and emptying pattern;Type 2 was defined as an emptying defect on the distal segment;and Type 3 was defined as a filling defect in the distal *** Segmented GB accounted for 63 cases(23.5%),including 36 patients(57.1%)with Type 1,18 patients(28.6%)with Type 2,and 9 patients(14.3%)with Type 3 emptying ***,approximately 43%of HBS images showed a discordant pattern as compared to anatomical imaging of segmented *** there were no significant differences in clinical symptoms,rate of cholecystectomy,or pathological findings based on the type,most gallstones occurred in the distal *** GBEF was 62.50%±24.79%for Type 1,75.89%±17.21%for Type 2,and 88.56%±7.20%for Type *** 1 showed no difference in reported GBEF compared to the non-segmented GB group(62.50%±24.79%vs 67.40%±21.78%).In contrast,the reported GBEF was higher in Types 2 and 3 with defective emptying and filling when compared to Type 1(80.11%±15.70%vs 62.57%±24.79%;P=0.001).CONCLUSION In segmented GB,discordance i

关键词： Gallbladder Segmented Gallbladder emptying Radionuclide imaging Misdiagnosis Cholecystitis

3-Dimensional liver volume assessment in patients with hepatitis B virus-related liver cirrhosis during long-term oral nucleos(t)ide analogues therapy

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World Journal of Gastroenterology 2017年第2期23卷 297-305页

作者： chang hun lee In Hee Kim Jin chang Moon Seung Young Seo Seong hun Kim Sang Wook Kim Seung Ok lee Soo Teik lee Dae Ghon Kim Jae Do Yang Hee Chul Yu Division of Gastroenterology Department of Internal MedicineChonbuk National University Medical School and Hospital Department of Surgery Chonbuk National University Medical School and Hospital

AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver *** reviewed the data of naïve patients with HBV-related liver cirrhosis, who had taken oral NUCs therapy, between 2003 and 2007 at Chonbuk University Hospital. We analyzed two consecutive sets of abdominal computerized tomography scans-one at the time of treatment initiation and another at the second-year follow-up. Liver volume was calculated by 3-dimensional liver extraction volumetry *** total of 55 patients (34 males) were included. There was 114.3 mL ± 167.8 mL (12.9% ± 17.9%) of increase in liver volume during the two years of NUCs therapy (993.8 mL ± 242.8 mL at baseline vs 1108.1 mL ± 263.3 mL at two-year follow-up, P < 0.001). The ratio of the measured baseline liver volume to the estimated standard liver volume was improved from 70.8% to 78.0%. An increase in liver volume was shown not only in patients with compensated cirrhosis (P = 0.046) but also in those with decompensated cirrhosis (P < 0.001). Significant factors for volume increases were Child-Turcotte-Pugh grade and model for end-stage liver disease score improvement without virological breakthrough. In multiple linear regression analysis, delta albumin and delta alanine aminotransferase levels showed a significant association with the increase in liver volume (P = 0.002 and 0.005, respectively).CONCLUSIONLong-term oral NUCs therapy in patients with HBV-related liver cirrhosis lead to significant increase in liver volume assessed with 3-dimensional liver extraction volumetry program.

关键词： Antiviral agents Liver cirrhosis Liver regeneration Image processing Computer-assisted

How Geography and International Relations Shaped Economic Development in Korea

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How Geography and International Relations Shaped Economic De...

How Geography and International Relations Shaped Economic Development in the Republic of Korea

北京论坛（2005）文明的和谐与共同繁荣——全球化视野中亚洲的机遇与发展

作者： hun-chang lee Department of Economics Korea University Sungbuk-Ku Anam-Dong 1SeoulKorea

Ⅰ.Introduction This paper argues that international relations have been the most important factor in determining Korea’s economic development,they have been fundamentally affected by geography,and geopolitics has be...

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How Geography and International Relations Shaped Economic De...

Ipsilateral retroperitoneal papillary renal cell carcinoma 27 years after simple nephrectomy for a renal abscess:A case report

文明的和谐与共同繁荣：全球化视野中亚洲的机遇与发展——北京论坛（2005）

作者： hun-chang lee Korea University

ⅠIntroduction This paper argues that international relations have been the most important factor in determining Republic of Korea’s economic development, they have been fundamentally affected by geography,and geopol...

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World Journal of Clinical Cases 2024年第20期12卷 4412-4418页

作者： Tae Nam Kim Ahrong Kim Kyung Bin Kim chang hun lee Department of Urology Pusan National UniversitySchool of MedicineBiomedical Research Institute and Pusan National University HospitalBusan 43241South Korea Department of Pathology Pusan National UniversitySchool of MedicineBusan 49241South Korea

BACKGROUND Cases of severe inflammatory renal disease and renal cell carcinoma(RCC)that occur simultaneously in the same kidney have been occasionally ***,extrarenal RCC that does not originate from the native kidney has rarely been *** our knowledge,this is the first reported case of RCC developing in the ipsilateral retroperitoneal space after a simple nephrectomy(SN)for inflammatory renal *** SUMMARY A 63-year-old woman was referred to our hospital following the incidental discovery of a left retroperitoneal mass without specific *** medical history revealed a left SN 27 years ago due to a renal *** resonance imaging of the abdomen revealed three oval masses in the left *** masses were successfully excised,and subsequent pathology confirmed papillary *** surgery,the patient remained disease-free for 11 years without adjuvant *** Clinicians should be vigilant of RCC in patients with retroperitoneal masses,especially after SN for inflammatory renal disease.

关键词： Abscess Papillary renal cell carcinoma Nephrectomy Adhesiveness Case report

Aligned Ion Conduction Pathway of Polyrotaxane‑Based Electrolyte with Dispersed Hydrophobic Chains for Solid‑State Lithium–Oxygen Batteries

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Nano-Micro Letters 2025年第2期17卷 169-186页

作者： Bitgaram Kim Myeong‑chang Sung Gwang‑Hee lee Byoungjoon Hwang Sojung Seo Ji‑hun Seo Dong‑Wan Kim Department of Materials Science and Engineering Korea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea School of Civil Environmental and Architectural EngineeringKorea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea Materials Science and Chemical Engineering Center Institute for Advanced Engineering(IAE)Yongin 17180Republic of Korea

A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety *** study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves ***-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain *** this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 *** situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen *** situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability *** present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.

关键词： Solid polymer electrolyte Lithium-oxygen batteries Polyrotaxane ion conductivity Hydrophobic chain

Tooth regeneration: a revolution in stomatology and evolution in regenerative medicine

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International Journal of Oral Science 2011年第3期3卷 107-116页

作者： Sibel Yildirim Susan Y. Fu Keith Kim Hong Zhou chang hun lee Ang Li Sahng Gyoon Kim Shuang Wang Jeremy J. Mao Tissue Engineering and Regenerative Medicine Laboratory （TERML） Center for Craniofacial Regeneration Columbia University Medical Center New York NY 10032 USA Department of Basic Science Xi＇an Jiaotong University School of Stomatology Xi＇ an 710049 China

A tooth is a complex biological organ and consists of multiple tissues including the enamel, dentin, cementum and pulp. Tooth loss is the most common organ failure. Can a tooth be regenerated？ Can adult stem cells be orchestrated to regenerate tooth structures such as the enamel, dentin, cementum and dental pulp, or even an entire tooth？ If not, what are the therapeutically viable sources of stem cells for tooth regeneration？ Do stem cells necessarily need to be taken out of the body, and manipulated ex vivo before they are transplanted for tooth regeneration？ How can regenerated teeth be economically competitive with dental implants？ Would it be possible to make regenerated teeth affordable by a large segment of the population worldwide？ This review article explores existing and visionary approaches that address some of the above-mentioned questions. Tooth regeneration represents a revolution in stomatology as a shift in the paradigm from repair to regeneration： repair is by metal or artificial materials whereas regeneration is by biological restoration. Tooth regeneration is an extension of the concepts in the broad field of regenerative medicine to restore a tissue defect to its original form and function by biological substitutes.

关键词： stem cells bioactive cues biomaterials cell homing dental pulp tooth regeneration growth factors scaffold dental implants pulp regeneration

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： Md Ahasan Habib Shusen Lin Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar Jae-hun Jeong Jihoon lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Advanced electrocatalyst High current Corrosion resistance Industrial requirement