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Accurate Approximation of the Earth Mover's Distance in Linear Time

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Journal of Computer Science & Technology 2014年第1期29卷 142-154页

作者： Min-Hee Jang Sang-wook kim Christos Faloutsos Sunju Park Computer Science Department Carnegie Mellon University ACM IEEE Department of Electronics and Computer Engineering Hanyang University School of Business Yonsei University

Color descriptors are one of the important features used in content-based in, age retrieval. The dominant color descriptor （DCD） represents a few perceptually dominant colors in an image through color quantization. For image retrieval based on DCD, the earth mover＇s distance （EMD） and the optimal color composition distance were proposed to measure the dissimilarity between two images. Although providing good retrieval results, both methods are too time-consuming to be used in a large image database. To solve the problem, we propose a new distance function that calculates an approximate earth mover＇s distance in linear time. To calculate the dissimilarity in linear time, the proposed approach employs the space-filling curve for multidimensional color space. To improve the accuracy, the proposed approach uses multiple curves and adjusts the color positions. As a result, our approach achieves order-of-magnitude time improvement but incurs small errors. We have performed extensive experiments to show the effectiveness and efficiency of the proposed approach. The results reveal that our approach achieves almost the same results with the EMD in linear time.

关键词： earth mover's distance approximation content-based image retrieval

Effect of soil pH on the sorption capacity of soil organic matter for polycyclic aromatic hydrocarbons in unsaturated soils

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Pedosphere 2023年第2期33卷 365-371页

作者： Pil-Gon kim Abhrajyoti TARAFDAR Jung-hwan KWON Division of Environmental Science and Ecological Engineering Korea University145 Anam-roSeongbuk-guSeoul 02841(Korea)

Sorption by soil organic matter(SOM)is considered the most important process affecting the bioavailability of hydrophobic organic chemicals(HOCs)in *** sorption capacity of SOM for HOCs is affected by many environmental *** this study,we investigated the effects of soil pH and water saturation level on HOC sorption capacity of SOM using batch sorption *** of soil organic carbon-water partition coefficient(K_(OC))of six selected polycyclic aromatic hydrocarbons(PAHs)were measured in an artificial soil under various soil pH and water saturation *** sampling was used to measure K_(OC)with polydimethylsiloxane as the sampling *** of soil pH,K_(OC)increased with increasing soil water saturation level for lower-molecular-weight *** contrast,K_(OC)decreased with increasing soil water saturation level for higher-molecular-weight *** some fluctuations,K_(OC)tended to decrease with increasing soil pH at all water saturation *** indicates that earlier studies on the effects of soil pH on K_(OC)under saturated conditions could be extended to unsaturated *** K_(OC)tendencies were reproduced in three different natural soils,suggesting that the effects of soil water saturation level and pH might be generalized,at least for *** PAH sorption capacity of SOM was found to be resilient under dynamic soil pH conditions,which can be used to adjust the effects of soil pH.

关键词： contaminated soil hydrophobic organic chemical partition coefficient passive sampling pollutant soil water saturation level

Electrochemical Performance and ex situ Analysis of ZnMn2O4 Nanowires as Anode Materials for Lithium Rechargeable Batteries

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Nano Research 2011年第5期4卷 505-510页

作者： Sung-wook kim Hyun-wook Lee Pandurangan Muralidharan Dong-Hwa Seo Won-Sub Yoon Do Kyung kim Kisuk Kang Research Institute of Advanced Materials Seoul National University 599 Kwanak-ro Kwanak-gu Seoul 151-742 Republic of Korea Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology 335 Gwahangno Yuseong-gu Daejeon 305-701 Republic of Korea Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology 335 Gwahangno Yuseong-gu Daejeon 305-701 Republic of Korea Department of Materials Science and Engineering Seoul National University 599 Kwanak-ro Kwanak-gu Seoul 151-742 Republic of Korea

One-dimensional ZnMn2O4 nanowires have been prepared and investigated as anode materials in Li rechargeable batteries. The highly crystalline ZnMn2O4 nanowires about 15 nm in width and 500 nm in length showed a high specific capacity of about 650 mAh.g-1 at a current rate of 100 mA.g-1 after 40 cycles. They also exhibited high power capability at elevated current rates, i.e., 450 and 350 mAh.g 1 at current rates of 500 and 1000 mA.g 1, respectively. Formation of Mn3O4 and ZnO phases was identified by ex situ X-ray diffraction （XRD） and transmission electron microscopy （TEM） studies after the initial discharge-charge cycle, which indicates that the ZnMn2O4 phase was converted to a nanocomposite of Mn3O4 and ZnO phases immediately after the electrochemical conversion reaction.

关键词： Energy storage lithium rechargeable battery anode ZnMn204 nanowire

URANS simulations for a free-running container ship:Part 2. Added power

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Journal of Hydrodynamics 2021年第3期33卷 448-467页

作者： Dong-hwan kim Yugo Sanada Hamid Sadat-Hosseini Frederick Stern IIHR-Hydroscience and Engineering The University of IowaIowa CityUSA Costal Development and Ocean Energy Research Center Korea Institute of Ocean Science and TechnologyBusanKorea Mechanical Engineering University of North TexasDentonUSA

Part 2 reports the validation,local force and local flow study results for the free-running added power simulations whose conditions are the same as the self-propulsion test except for the increased propeller rotational speed and the presence of *** targeting the same mean Froude number in the wave condition,the propeller requires the increased propeller rotational speed for the operation at the low advance ratio due to the added *** test is performed at five different wavelengths in head waves and four different headings in the oblique *** the validation study,the time series of the validation variables is decomposed with discrete Fourier transform to extract the harmonic *** variables are global parameters,including motions,propeller thrust,and torque coefficients,added power variables,and self-propulsion factors which show reasonable agreement against the experiment results and produces a similar error from the self-propulsion *** local force study shows that the added resistance mostly appears at the bow due to the bow plunging during the short head wave and resonance *** contributions of the gravitational force and the buoyant force are found to increase as the stern motion exceeds the bow motion during the long head wave *** oscillation of the propeller performances shows correlation with the first harmonic amplitude of the propeller ***,pitch,and roll decay tests are performed prior to the main test to assess the natural frequencies of the *** as Part 1,a discretized propeller is used.

关键词： Added power unsteady Reynolds-averaged Navier-Stokes(URANS) KRISO Container Ship(KCS) CFDShip-IOWA

Recurrent atypical leiomyoma in bladder trigone,confused with uterine fibroids:A case report

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World Journal of Clinical Cases 2022年第29期10卷 10728-10734页

作者： Jeonghwa Song Heekyoung Song Yong-wook kim Department of Obstetrics and Gynecology College of MedicineThe Catholic University of KoreaIncheon St.Mary’s HospitalIncheon 21431South Korea

BACKGROUND Tumors originating from the posterior bladder wall can be challenging to diagnose because they may mimic a mass from the uterine *** leiomyoma of the bladder trigone is extremely rare,with few reported cases,and requires caution during surgery to avoid damage to the adjacent *** surgery and confirmational pathology are essential to assess whether the tumor is malignant and relieve clinical ***,we describe a case of recurrent leiomyoma with focal atypia in the bladder *** SUMMARY A 29-year-old woman with a uterine fibroid incidentally found at a regular checkup was referred to our *** on magnetic resonance imaging,either urinary bladder leiomyoma or protrusion of pedunculated uterine cervical fibroid into the bladder was *** leiomyoma in the trigone of the bladder was completely excised by laparotomy,and the patient was discharged without ***-up outpatient ultrasonography identified tumor recurrence after four *** focal atypia was identified previously,laparotomy was performed to confirm the pathology.A round solid mass was resected from the posterior bladder wall without injuring either ureteric *** tumor was pathologically diagnosed as a leiomyoma without ***-year follow-up ultrasonography has revealed no *** Atypical leiomyoma in bladder trigone is rare and could be easily mistaken for fibroid in the uterine *** confirm histopathology,surgical excision is mandatory and regular follow-up is necessary to detect recurrence.

关键词： Case report Cervix uteri Leiomyoma Recurrence Trigone Urinary bladder

Essentials of thoracic outlet syndrome:A narrative review

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World Journal of Clinical Cases 2021年第21期9卷 5804-5811页

作者： Min Cheol Chang Du hwan kim Department of Rehabilitation Medicine College of MedicineYeungnam UniversityDaegu 42415South Korea Department of Physical Medicine and Rehabilitation College of MedicineChung-Ang UniversitySeoul 06973South Korea

Thoracic outlet syndrome(TOS)is a group of diverse disorders involving compression of the nerves and/or blood vessels in the thoracic outlet *** results in pain,numbness,paresthesia,and motor weakness in the affected upper *** reviewed the pathophysiology,clinical evaluation,differential diagnoses,and treatment of *** is usually classified into three types,neurogenic,venous,and arterial,according to the primarily affected *** true neurogenic and disputed TOS are considered neurogenic *** identifying the causative lesions is complex,detailed history taking and thorough clinical investigation are *** and imaging studies are helpful for excluding other possible disorders and confirming the diagnosis of true neurogenic *** existence of a disputed TOS remains *** physicians tend to be skeptical about the existence of disputed TOS,but thoracic surgeons argue that disputed TOS is *** who encounter patients with TOS need to understand its key features to avoid misdiagnosis and provide appropriate treatment.

关键词： Brachial plexus Diagnosis Review Thoracic outlet syndrome Treatment Neuromuscular lesions

Unknown Attack Detection:Combining Relabeling and Hybrid Intrusion Detection

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Computers, Materials & Continua 2021年第9期68卷 3289-3303页

作者： Gun-Yoon Shin Dong-wook kim Sang-Soo kim Myung-Mook Han Department of Computer Engineering Gachon UniversitySungnam-si13120Korea Agency for Defense Development Songpa Seoul05661Korea Department of Software Gachon UniversitySungnam-si13120Korea

Detection of unknown attacks like a zero-day attack is a research field that has long been ***,advances in Machine Learning(ML)and Artificial Intelligence(AI)have led to the emergence of many kinds of attack-generation tools developed using these technologies to evade detection *** detection and misuse detection are the most commonly used techniques for detecting intrusion by unknown *** anomaly detection is adequate for detecting unknown attacks,its disadvantage is the possibility of high false *** detection has low false alarms;its limitation is that it can detect only known *** overcome such limitations,many researchers have proposed a hybrid intrusion detection that integrates these two detection *** method can overcome the limitations of conventional methods and works better in detecting unknown ***,this method does not accurately classify attacks like similar to normal or known ***,we proposed a hybrid intrusion detection to detect unknown attacks similar to normal and known *** anomaly detection,the model was designed to perform normal detection using Fuzzy c-means(FCM)and identify attacks hidden in normal predicted data using *** misuse detection,the model was designed to detect previously known attacks using Classification and Regression Trees(CART)and apply Isolation Forest(iForest)to classify unknown attacks hidden in known *** an experiment result,the application of relabeling improved attack detection accuracy in anomaly detection by approximately 11%and enhanced the performance of unknown attack detection in misuse detection by approximately 10%.

关键词： Unknown attack hybrid intrusion detection fuzzy c-means relabeling CART iForest

Analysis of Feature Importance and Interpretation for Malware Classification

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Computers, Materials & Continua 2020年第12期65卷 1891-1904页

作者： Dong-wook kim Gun-Yoon Shin Myung-Mook Han Department of Computer Engineering Gachon UniversitySungnam-si13120Korea Department of Software Gachon UniversitySungnam-si13120Korea

This study was conducted to enable prompt classification of malware,which was becoming increasingly *** do this,we analyzed the important features of malware and the relative importance of selected features according to a learning model to assess how those important features were ***,the analysis features were extracted using Cuckoo Sandbox,an open-source malware analysis tool,then the features were divided into five categories using the extracted *** 804 extracted features were reduced by 70%after selecting only the most suitable ones for malware classification using a learning model-based feature selection method called the recursive feature ***,these important features were *** level of contribution from each one was assessed by the Random Forest classifier *** results showed that System call features were mostly *** the end,it was possible to accurately identify the malware type using only 36 to 76 features for each of the four types of malware with the most analysis samples *** were the Trojan,Adware,Downloader,and Backdoor malware.

关键词： Recursive feature elimination model interpretability feature importance malware classification

Passivation engineering via silica‐encapsulated quantum dots for highly sensitive photodetection

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Carbon Energy 2023年第9期5卷 49-62页

作者： Ji Yun Chun Byung Gi kim Jin Young kim Woongsik Jang Dong hwan Wang School of Integrative Engineering Chung‐Ang UniversitySeoulRepublic of Korea

Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical *** nanoscale perovskite materials such as quantum dots(QDs)show novel behavior,they have intrinsic stability *** this study,an effectively silane barrier-capped quantum dot(QD@APDEMS)is thinly applied onto a bulk perovskite photosensitive layer for use in ***@APDEMS is synthesized with a silane ligand with hydrophobic CH_(3)-terminal groups,resulting in excellent dispersibility and durability to enable effective *** introduction of the QD@APDEMS layer results in the formation of a lowdefect perovskite film with enlarged *** is attributed to the grain boundary interconnection effect via interaction between the functional groups of QD@APDEMS and uncoordinated Pb^(2+)in grain *** passivating the grain boundaries,where various trap sites are distributed,hole chargecarrier injection and shunt leakage can be ***,from the energy point of view,the deep highest occupied molecular orbital(HOMO)level of QD@APDEMS can work as a hole charge injection *** charge dynamics(generation,transfer,and recombination properties)and reduced trap density of QD@APDEMS are *** this perovskite film is used in a photodetector,the device performance(especially the detectivity)stands out among existing perovskites evaluated for energy sensing device applications.

关键词： grain boundary passivation perovskite quantum dots photodetectors photosensitive layers trap