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Energy & Environmental Materials 2024年第2期7卷 83-92页

作者： Hak Hyeon Lee Dong Su Kim Swagotom Sarker Ji hoon choi Ho Seong Lee Hyung Koun Cho Department of Advanced Materials Science&Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-doSeoul 16419Korea Department of Advanced Materials Science&Engineering Kyungpook National University80Daehak-roBuk-guDaegu 41566Korea

Rh has been widely studied as a catalyst for the promising hydrazine oxidation reaction that can replace oxygen evolution reactions for boosting hydrogen production from hydrazine-containing *** Rh being expensive,only a few studies have examined its electrocatalytic mass ***,surface-limited cation exchange and electrochemical activation processes are designed to remarkably enhance the mass activity of *** atoms were readily replaced at the Ni sites on the surface of NiOOH electrodes by cation exchange,and the resulting RhOOH compounds were activated by the electrochemical reduction *** cation exchange-derived Rh catalysts exhibited particle sizes not exceeding 2 nm without agglomeration,indicating a decrease in the number of inactive inner Rh ***,an improved mass activity of 30 A mg_(Rh)^(-1)was achieved at 0.4 V versus reversible hydrogen ***,the two-electrode system employing the same CE-derived Rh electrodes achieved overall hydrazine splitting over 36 h at a stable low *** proposed surface-limited CE process is an effective method for reducing inactive atoms of expensive noble metal catalysts.

关键词： cation exchange synthesis electrochemical metallization hydrazine oxidation reaction mass activity rhodium catalyst

Effects of smoking on cerebral and ventricular volumes in healthy males

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Neural Regeneration Research 2011年第1期6卷 72-75页

作者： Hyun-Jun Kim Mi-Hyun choi Beob-Yi Lee Su-Jeong Lee Jae-Woong Yang Ji-Hye Kim Jin-seung choi Dong-Won Kang Jang-Yeon Park Jae-hoon Jun Gye-Rae Tack Soon-Cheol Chung Department of Obstetrics & Gynecology Konkuk University Department of Biomedical Engineering Research Institute of Biomedical EngineeringCollege of Biomedical & Health ScienceKonkuk University Department of Anatomy School of MedicineKonkuk University

Previous studies have reported decreased cerebral volume as a result of smoking. However, little is known about accompanying changes in ventricular volume for healthy subjects who smoke, although ventricular volume is increased in patients with multiple sclerosis who smoke. The present study analyzed whether cerebral volume decreased with smoking through the use of magnetic resonance imaging. In addition, accompanying changes in ventricular volume that resulted from decreased cerebral volume and smoking were analyzed in healthy subjects. When multivariate analysis of covariance was performed by integrating the 2 age groups, aged 20-28 years and 40-49 years, with statistical significance, results showed that cerebral volume of smokers was smaller and ventricular volume was greater compared with the non-smokers. These findings suggest that ventricular volume changes could be utilized to characterize the effects of smoking.

关键词： smoking cerebral and ventricular volumes magnetic resonance imaging

Gene-diet interactions in gastric cancer risk: A systematic review

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World Journal of Gastroenterology 2014年第28期20卷 9600-9610页

作者： Jeongseon Kim Young Ae Cho Wook Jin choi seung Hwa Jeong Molecular Epidemiology Branch Division of Cancer Epidemiology and PreventionResearch InstituteNational Cancer Center

AIM:To conduct a systematic review of the published epidemiological studies investigating the association of the interactions between gene variants and dietary intake with gastric cancer ***:A literature search was conducted in PubMed,EMBASE,and MEDLINE for articles published between January 2000 and July 2013,and 38 studies were *** studies included various dietary factors(e.g.,fruits and vegetables,soybean products,salt,meat,and alcohol)and genetic variants that are involved in various metabolic ***:Studies suggest that individuals who carry high-risk genetic variants and demonstrate particular dietary habits may have an increased risk of gastric cancer compared with those who do not carry high-risk genetic *** dietary patterns and variations in the frequency of genetic variants may explain the higher incidence of gastric cancer in a particular ***,most previous studies have limitations,such as a small sample size and a retrospective casecontrol *** addition,past studies have been unable to elucidate the specific mechanism in gene-diet interaction associated with gastric ***:Additional large prospective epidemiological and experimental studies are required to identify the gene-diet metabolic pathways related to gastric cancer susceptibility.

关键词： Gastric cancer Gene Diet Interaction

Thermal performance analysis of borehole size effect on geothermal heat exchanger

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Journal of Central South University 2012年第12期19卷 3524-3529页

作者： choi hoon-ki YOO Geun-jong LIM Kyung-bin LEE Sang-hoon LEE Chang-hee Department of Mechanical Design and Manufacturing Engineering Changwon National UniversityChangwon 641-773Korea Department of Mechanical Design Engineering Hanbat National UniversityDaejon 305-719Korea Department of Energy Engineering Jeonju UniversityJeonju 560-759Korea STX Institute of Technology Changwon 642-845Korea

Thermal performance was the most important factor in the development of borehole heat exchanger utilizing geothermal energy. The thermal performance was affected by many different design parameters, such as configuration type and borehole size of geothermal heat exchanger. These eventually determined the operation and cost efficiency of the geothermal heat exchanger system. The main purpose of this work was to assess the thermal performance of geother^nal heat exchanger with variation of borehole sizes and numbers of U-tubes inside a borehole. For this, a thermal response test rig was established with line-source theory. The thermal response test was performed with in-line variable input heat source. Effective thermal conductivity and thermal resistance were obtained from the measured data. From the measurement, the effective thermal conductivity is found to have similar values for two- pair type （4 U-tubes） and three-pair type （6 U-tubes） borehole heat exchanger systems indicating similar heat transfer ability. Meanwhile, the thermal resistance shows lower value for the three-pair type compared to the two-pair type. Measured data based resistance have lower value compared to computed result from design programs. Overall comparison finds better thermal performance for the three-pair type, however, fluctuating temperature variation indicates complex flow behavior inside the borehole and requires further study on flow characteristics.

关键词： large size borehole heat exchanger thermal response test effective thermal conductivity thermal resistance borehole

Characteristic analysis of bleeding effect on standing column well (SCW) type geothermal heat exchanger

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Journal of Central South University 2012年第11期19卷 3202-3207页

作者： choi hoon-ki YOO Geun-jong LIM Kyung-bin LEE Sang-hoon LEE Chang-hee Department of Mechanical Design/Manufacturing Engineering Changwon National UniversityChangwon 641-773Korea Department of Mechanical Design Engineering Hanbat National UniversityDaejon 305-719Korea Department of Energy Engineering Jeonju UniversityJeonju 560-759Korea STX Institute of Technology Gyeongnam 642-845Korea

Thermal performance is the most important factor in the development of a borehole heat exchanger utilizing geothermal *** thermal performance is affected by many different design parameters and different operating conditions such as *** eventually determines the operation and cost efficiency of the borehole heat exchanger *** thermal performance of an open standing column well (SCW) type geothermal heat exchanger was assessed under the influence of *** this,a thermal response test rig was established with line-source *** test rig also had a bleeding function by releasing fluid while taking additional underground water through the heat *** thermal response test was performed with an additional constant input heat *** thermal conductivity and thermal resistance were obtained from the measured *** the measurement,the effective thermal conductivity is found to have 1.47 times higher value when bleeding is *** thermal resistance also increases by 1.58 times compared to a non-bleeding *** trend indicates enhanced heat transfer in the SCW type heat exchanger with a bleeding ***,therefore,could be an effective method of achieving a high heat transfer rate in the SCW type heat exchanger with sufficient underground water supply.

关键词： standing column well type thermal response test effective thermal conductivity thermal resistance bleeding effect

Importance of Adaptive Photometric Augmentation for Different Convolutional Neural Network

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Computers, Materials & Continua 2022年第9期72卷 4433-4452页

作者： Saraswathi Sivamani Sun Il Chon Do Yeon choi Dong hoon Lee Ji Hwan Park AI Reliability Lab ThinkforBL Consultancy ServicesGangnamSeoulKorea Department of Biosystems Engineering Chungbuk National UniversityCheongju-siChungcheongbuk-do28644Korea

Existing segmentation and augmentation techniques on convolutional neural network(CNN)has produced remarkable progress in object ***,the nominal accuracy and performance might be downturned with the photometric variation of images that are directly ignored in the training process,along with the context of the individual CNN *** this paper,we investigate the effect of a photometric variation like brightness and sharpness on different *** observe that random augmentation of images weakens the performance unless the augmentation combines the weak limits of photometric *** approach has been justified by the experimental result obtained from the PASCAL VOC 2007 dataset,with object detection CNN algorithms such as YOLOv3(You Only Look Once),Faster R-CNN(Region-based CNN),and SSD(Single Shot Multibox Detector).Each CNN model shows performance loss for varying sharpness and brightness,ranging between−80%to 80%.It was further shown that compared to random augmentation,the augmented dataset with weak photometric changes delivered high performance,but the photometric augmentation range differs for each ***,we discuss some research questions that benefit the direction of the *** results prove the importance of adaptive augmentation for individual CNN model,subjecting towards the robustness of object detection.

关键词： Object detection photometric variation adaptive augmentation convolutional neural network

Clinical characteristics of asymptomatic Terson syndrome in the patients with aneurysmal subarachnoid hemorrhage

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International Journal of Ophthalmology(English edition) 2020年第2期13卷 292-300页

作者： Hae Min Kang Jin Mo Cho So Yeon Kim Jeong hoon choi Department of Ophthalmology Catholic Kwandong UniversityInternational St.Mary’s HospitalIncheon 22711Republic of Korea Department of Neurosurgery Catholic Kwandong UniversityInternational St.Mary’s HospitalIncheon 22711Republic of Korea Department of Ophthalmology Choikang Eye ClinicSeoul 01110Republic of Korea

●AIM:To investigate clinical characteristics of asymptomatic Terson syndrome and its clinical impact in patients with aneurysmal subarachnoid hemorrhage(SAH).●METHODS:This retrospective,interventional study included 31 patients with aneurysmal SAH,and the medical records were *** addition to baseline characteristics of the study population such as age,sex,and underlying medical history,multi-modal imaging analysis,including fluorescein angiography(FA),spectral domain optical coherence tomography(SD-OCT),were also *** Coma Scale(GCS),Hunt-Hess(HH)grade,and Fisher scale at the time of admission,and functional outcome by using modified Rankin Scale(mRS)at 6 mo were compared.●RESULTS:Of the 31 patients,10 patients(32.3%)were diagnosed with Terson *** the patients with Terson syndrome did not report visual symptoms at the time of ophthalmologic *** showed microvascular changes of retinal capillaries and varying degrees of disc ***-OCT allowed intuitive anatomical localization of multi-layered retinal hemorrhages and assessment of ellipsoid zone *** patients with Terson syndrome showed significantly worse GCS(P=0.047)and HH grade(P=0.025)than those without,except Ficher scale(P=0.385).There was no significant difference in the mRS(P=0.250)at 6 *** baseline factors,the HH grade was the only significant factor associated with Terson syndrome(B=1.079,P=0.016).●CONCLUSION:In our study,32.3%of the patients have Terson syndrome without visual *** baseline HH grade is significantly correlated with Terson syndrome,and there is no significant difference in the functional outcome between the patients with and without Terson *** syndrome may develop without any visual symptoms as shown in our study,and ophthalmologic screening may be recommended to prevent further visual deterioration especially in the patients with poor HH grade at the time of aneurysmal SAH.

关键词： cerebral aneurysm subarachnoid hemorrhage Terson syndrome

Spatial and spectral measurement of laser-driven protons through radioactivation

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Nuclear Science and Techniques 2023年第12期34卷 30-39页

作者： Yin‑Ren Shou Xue‑Zhi Wu Gwang‑Eun Ahn seung Yeon Kim Seong hoon Kim Hwang Woon Lee Jin Woo Yoon Jae Hee Sung Seong Ku Lee Xue‑Qing Yan Il Woo choi Chang Hee Nam Center for Relativistic Laser Science Institute for Basic ScienceGwangju 61005Republic of Korea School of Physics Peking UniversityBeijing 100871China Advanced Photonics Research Institute Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Physics and Photon Science Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea

The simultaneous measurement of the spatial profile and spectrum of laser-accelerated protons is important for further optimization of the beam qualities and *** report a detailed study regarding the underlying physics and regular procedure of such a measurement through the radioactivation of a stack composed of aluminum,copper,and CR-39 plates as well as radiochromic films(RCFs).After being radioactivated,the copper plates are placed on imaging plates(IPs)to detect the positrons emitted by the reaction products through contact *** spectrum and energy-dependent spatial profile of the protons are then obtained from the IPs and confirmed by the measured ones from the RCFs and CR-39 *** also discuss the detection range,influence of electrons,radiation safety,and spatial resolution of this ***,insights regarding the extension of the current method to online measurements and dynamic proton imaging are also provided.

关键词： Laser-driven proton acceleration Proton-induced nuclear reaction Radioactivation measurement Contact imaging

Predictors of the patency of self-expandable metallic stents in malignant gastroduodenal obstruction

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World Journal of Gastroenterology 2015年第30期21卷 9134-9141页

作者： seung Han Kim hoon Jai Chun In Kyung Yoo Jae Min Lee seung Joo Nam Hyuk Soon choi Eun Sun Kim Bora Keum Yeon Seok Seo Yoon Tae Jeen Hong Sik Lee Soon Ho Um Chang Duck Kim Division of Gastroenterology and Hepatology Department of Internal MedicineKorea University College of Medicine

AIM:To investigate the predictive factors of selfexpandable metallic stent patency after stent placement in patients with inoperable malignant gastroduodenal obstruction. METHODS:A total of 116 patients underwent stent placements for inoperable malignant gastroduodenal obstruction at a tertiary academic center. Clinical success was defined as acceptable decompression of the obstructive lesion within the malignant gastroduodenal neoplasm. We evaluated patient comorbidities and clinical statuses using the World Health Organization's scoring system and categorized patient responses to chemotherapy using the Response Evaluation Criteria in Solid Tumors criteria. We analyzed the relationships between possible predictive factors and stent patency. RESULTS:Self-expandable metallic stent placement was technically successful in all patients(100%),and the clinical success rate was 84.2%. In a multivariate Cox proportional hazards model,carcinoembryonic antigen(CEA) levels were correlated with a reduction in stent patency [P = 0.006; adjusted hazard ratio(a HR)= 2.92,95%CI:1.36-6.25]. Palliative chemotherapy was statistically associated with an increase in stent patency(P = 0.009; a HR = 0.27,95%CI:0.10-0.72).CONCLUSION:CEA levels can easily be measured at the time of stent placement and may help clinicians to predict stent patency and determine the appropriate stent procedure.

关键词： Malignant gastroduodenal obstruction Stent Patency Predictive factor Carcinoembryonicantigen

Diagnostic value of maximal-outer-diameter and maximal-mural-thickness in use of ultrasound for acute appendicitis in children

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World Journal of Gastroenterology 2009年第23期15卷 2900-2903页

作者： Bo-Kyung Je Sung-Bum Kim seung Hwa Lee Ki Yeol Lee Sang hoon Cha Department of Radiology College of Medicine Korea University #516 Gojan1-Dong Danwon-Gu Ansan-City Gyeonggi-Do 425-707 South Korea Department of Internal Medicine Dongshin Hospital #430 Hongeundong Seodaemungu Seoul 120-100 South Korea

MM： To evaluate the maximal-outer-diameter （MOD） and the maximal-mural-thickness （MMT） of the appendix in children with acute appendicitis and to determine their optimal cut-off values to diagnose acute appendicitis.METHODS： In total, 164 appendixes from 160 children between 1 and 17 years old （84 males, 76 females; mean age, 7.38 years） were examined by high-resolution abdominal ultrasound for acute abdominal pain and the suspicion of acute appendicitis. We measured the MOD and the MMT at the thickest point of the appendix. Patients were categorized into two groups according to their medical records： patients who had surgery （surgical appendix group） and patients who did not have surgery （non-surgical appendix group）. Data were analyzed by MedCalc v.9.3. The rank sum test （Mann-Whitney test） was used to evaluate the difference in the MOD and the MMT between the two groups. ROC curve analysis was used to determine the optimal cut-off value of the MOD and the MMT on diagnosis of acute appendicitis.RESULTS： There were 121 appendixes （73.8%） in the non-surgical appendix group and 43 appendixes （26.2%） in the surgical appendix group. The median MOD differed significantly between the two groups （0.37 cm vs 0.76 cm, P〈 0.0001）, and the median MMT also differed （0.15 cm vs 0.33 cm, P 〈 0.0001）. The optimal cut-off value of the MOD and the MMT for diagnosis of acute appendicitis in children was 〉 0.57 cm （sensitivity 95.4%, specificity 93.4%） and 〉 0.22 cm （sensitivity 90.7%, specificity 79.3%）, respectively.CONCLUSION： The MOD and the MMT are reliable criteria to diagnose acute appendicitis in children. An MOD 〉 0.57 cm and an MMT 〉 0.22 cm are the optimal criteria.

关键词： Appendicitis Ultrasonography Pediatrics Diagnosis ROC curve