Research

Publications

Referred Journal Publication

2024 Heuisoo Kim, Seongye Kang, Insik Han, Youngjin Eun, Junyoung Nam, Dongchoul Kim, "Predection of micro wear depth between engineering polymers", Journal of Manufacturing Processes , Volume 124 :  1124-1134
2024 Ju A. La, Hyunjoo Lee, Donchoul Kim, Hyungduk Ko, and Taewook Kang. "Enhanced Molecular Interaction of 3D Plasmonic Nanoporous Gold Alloys by Electronic Modulation for Sensitive Molecular Detection", Nano Letters (IF : 10.8, Ranking : 11.79%).
2024 Sunghoon Choi, Jongwon Shin, Joung Sik Suh, Dongchoul Kim.  "Modeling asymmetric fracture mechanics of Mg alloy wire in drawing process", Journal of Magnesium and Alloys (IF :  17.6, Ranking : 0.6%).
2024 Hyunjoo Lee, Dongchoul Kim. "Recent Computational Approaches for Accelerating Dendrite Growth Prediction: A Short Review", Multiscale Science and Engineering  : 1-7.
2024 Seungyeon Han, Hyun Ji An, Taejin Kwak, Miseol Kim, Dongchoul Kim, Luke P Lee, Inhee Choi. "Plasmonic Optical Wells-Based Enhanced Rate PCR.", Nano Letters (IF :  10.8, Ranking :  11.79%), 24.5: 1738-1745.
2023 Shin, Y., Kwak, T., Whang, K., Jo, Y., Hwang, J. H., Hwang, I.,An, H, J., Lim, Y., Choi, I., Kim, D., Lee, L, P., & Kang, T. "Bubble-free diatoms polymerase chain reaction.", Biosensors and Bioelectronics (IF : 12.6, Ranking : 2.33%), 237, 115489.
2022 Lee, H., Kwak, T., Lee, W., Song, J., & Kim, D. "Effect of surface topography on dendritic growth in lithium metal batteries.", Journal of Power Sources (IF :  9.797, Ranking: 11.2%), 552, 232264.

2022 Lee, W., Lee, H. C., Kwak, T., Kim, H. J., Kim, S. R., & Kim, D. "Lee, W., Lee, H. C., Kwak, T., Kim, H. J., Kim, S. R., & Kim, D." International journal of crashworthiness, 27(6), 1883-1890.
2022 Park, J., Lee, S., Lee, H., Han, S., Kang, T. H., Kim, D., Kang, T. & Choi, I. "Colloidal Multiscale Assembly via Photothermally Driven Convective Flow for Sensitive In‐Solution Plasmonic Detections." Small (IF : 13.281, Ranking : 7.34%) , 2201075. 
2022 Whang, K., Shin, Y., Baek, W., Jo, Y., Hwang, J. H., Min, J., Kim, D. & Kang, T. "Direct and precise determination of volumetric mass transfer coefficient of carbon monoxide for miniaturized gas-liquid reactors via sensitive probing of raman transitions." Chemical Engineering Journal (IF : 13.273, Ranking : 2.45%), 429, 132260.
2021 Kim, Y., Lim, Y., Cha, D. E., Kim, D. "Simulation of Reversible Plasticity Shape Memory Polymer with Designed Strain Rate Dependent Failure Model." Multiscale Science and Engineering 3.1: 88-94.
2021 Kwak, T., & Kim, D. "Controlling Equilibrium Morphologies of Bimetallic Nanostructures Using Thermal Dewetting via Phase-Field Modeling." Materials 14.21: 6697.
2021 Whang, K., Jo, Y., Lee, H., Kim, D., Kang, T. "Water-Wettable Open Plasmonic Nanocavities for Ultrasensitive Molecular Detections in Multiple Phases." Nano Letters (IF : 11.189, Ranking : 9.43%) 21.14: 6194-6201.
2021 Song, J., Kim, D., Lee, L. P. "Mechanobiological Stimulations of Algal Cells for Energy Harvesting." Advanced Theory and Simulations, 4.6: 2000281.
2021 Shin, Y., Lim, Y., Kwak, T., Hwang, J. H., Georgescu, A., Huh, D., Kim, D. & Kang, T. Microfluidic Multi‐Scale Homogeneous Mixing with Uniform Residence Time Distribution for Rapid Production of Various Metal Core–Shell Nanoparticles. Advanced Functional Materials (IF : 18.808, Ranking : 4.34%), 31(5), 2007856.
2020 W. Lee, H. Lee, J. Bae, D. Kim. "Optimization of Manufacturing Process for Exterior Quality of Commercial Vehicle by Multi-physics Simulations." Multiscale Science and Engineering: 1-13.
2020 W. Lee, J. Lee, W. Kyoung, H. Lee, H. Lee, D. Kim. "Effect of inhomogeneous composition on the thermal conductivity of an Al alloy during the precipitation-hardening process." Journal of Materials Research and Technology 9.5 : 10139-10147.
2020 J. Kim, H. Lee, H. Choi, B. Lee, D. Kim. "Prediction of load-displacement curves of flow drill screw and RIVTAC joints between dissimilar materials using artificial neural networks." Journal of Manufacturing Processes 57: 400-408.
2019 H. Lee, W. Lee,J. Moon and D. Kim. "Geometric Effect of Grating-Patterned Electrode for High Conversion Efficiency of Dye-Sensitized Solar Cells." Multiscale Science and Engineering 1.2: 161-166.
2019 Y. Kim, K. Jung, J. Chang, T. Kwak, Y. Lim, S. Kim, J. Na, J. Lee, I. Choi, L. P. Lee, D. Kim and T. Kang. "Active Surface Hydrophobicity Switching and Dynamic Interfacial Trapping of Microbial Cells by Metal Nanoparticles for Preconcentration and In-Plane Optical Detection." Nano letters (IF : 11.189, Ranking : 9.43%) 19.10 : 7449-7456.
2019 J. Song, D. Kim. "Tunable Quasi-Plasticity of Microscale Shape Memory Alloys.", Advanced Theory and Simulations 2.2: 1800147
2019 Lee, Sang Hun, Jihwan Song, Byungrae Cho, SoonGweon Hong, Ori Hoxha, Taewook Kang, Dongchoul Kim, and Luke P. Lee. "Bubble-free rapid microfluidic PCR.", Biosensors and Bioelectronics (IF : 10.618, Ranking : 4.09%) 126: 725-733.
2018 C. Jin, W. Lee, D. Kim, T. Kang, and I. Choi. "Light-Induced Colloidal Assembly: Photothermal Convection Lithography for Rapid and Direct Assembly of Colloidal Plasmonic Nanoparticles on Generic Substrates (Small 45/2018)", Small (IF : 13.281, Ranking : 7.34%) 14.45: 1870209.
2018 Jihwan Song, Junhyung Kim, Dongchoul Kim. "Design of a Porous Cathode Structure of High Performance Li-ion Battery", Material Science and Engineering 383.1: 012008.
2018 Devon Jensen, Jihwan Song, Dongchoul Kim, Jungchul Lee, Geofferey D. Bothun, Arijit Bose, Keunhan Park. "Design Analysis of Hybrid Silicon-on-nothing Photonic Crystal?nanoantenna Structures for Engineering of Midinfrared Radiative Properties.", Journal of Nanophotonics 12.6: 026005.
2018 L. Zhang, C. Cheng, J. Song, L. Wu and D. Kim "Temperature Induces Self-assembly of Silicon Nano/Micro-structure based on Multi-physics Approach", J. Wuhan Univ. Technol.-Mat.Sci.Edit. 33, 823-827
2018 Changmin Jin, Wooju Lee, Dongchoul Kim, Taewook Kang, and Inhee Choi. "Photothermal Convection Lithography for Rapid and Direct Assembly of Colloidal Plasmonic Nanoparticles on Generic Substrates.", Small (IF : 13.281, Ranking : 7.34%) 14, no. 45: 1803055
2018 S. Lee, S. Hong, J. Song, B. Cho, E. Han, S. Kondapavulur, D. Kim and L. Lee "Microphysiological Analysis Platform of Pancreatic Islet β-Cell Spheroids", Advanced healthcare materials (IF : 9.933, Ranking : 8.54%) 7, no. 2 : 1701111
2018 Whang, Keumrai, Jong-Hwan Lee, Yonghee Shin, Wooju Lee, Young Wan Kim, Dongchoul Kim, Luke P. Lee, and Taewook Kang "Plasmonic bacteria on a nanoporous mirror via hydrodynamic trapping for rapid identification of waterborne pathogens.", Light: Science & Applications 7, no. 1: 68
2017 L. Zhang, W.Zheng, J. Lee, L. Wu and D. Kim "A study of morphological evolution of silicon microstructure based on phase field model", Ferroelectrics, 520, 154-158.
2017 J. Chang, S. Yoo, W. Lee, D. Kim and T. Kang "Spontaneous Phase Transfer-Mediated Selective Removal of Heavy Metal Ions Using Biocompatible Oleic Acid", Scientific Reports (IF : 4.380, Ranking : 22.92%), 7, 16727.
2017 S. Baek, S. Ha, H. Lee, K. Kim, D. Kim and J. Moon "Monolithic Two-Dimensional Photonic Crystal Reflectors for the Fabrication of Highly Efficient and Highly Transparent Dye-Sensitized Solar Cells", ACS applied materials & interfaces (IF : 9.229, Ranking : 13.02%), 9, 37006-37012.
2017 J Song, J Kim, T Kang, D Kim. "Design of a Porous Cathode for Ultrahigh Performance of a Li-ion Battery: An Overlooked Pore Distribution.", Scientific Reports (IF : 4.380, Ranking : 22.92%), 7, 42521.
2016 J. Lee, Y. Shin, W. Lee, K. Whang, D. Kim, L. Lee, J. Choi, and T. Kang . "General and Programmable Synthesis of Hybrid Liposome/metal Nanoparticles.", Science Advances (IF : 14.143, Ranking : 6.25%), 2, 12.
2016 W. Lee, J. Song, J. Son, M. Gutierrez, T. Kang, D. Kim, and L. Lee, “Solar Optics-based Active Panel for Solar Energy Storage and Disinfection of Greywater”, Biomicrofluidics, 10, 054120.
2016 J. Song, L. Zhang, and D. Kim, "Design of silicon-on-nothing structure based on multi-physics analysis", Multiscale and Multiphysics Mechanics, 1, 225-231.
2016 I. Choi, Y. Shin, J. Song (Co-First Author), S. Hong, Y. Park, D. Kim (Co-Corresponding Author), T. Kang, L. Lee, "Spontaneous Self-Formation of 3D Plasmonic Optical Structures", ACS Nano (IF : 15.881, Ranking : 6.14%), 10, 7639.
2016 D. Y. Kang, W. Lee (Co-First Author), D. Kim (Co-Corresponding Author), J. H. Moon, "Three-dimensional Polymeric Mechanical Metamaterials Fabricated by Multi-beam Interference Lithography with the Assistance of Plasma Etching", Langmuir, 32, 8436.
2016 J. Lee, J. Song, S. Kim, W. Lee, J. Jackman, D. Kim, N. Cho, and J. Lee, “Multifunctional hydrogel nano-probes for atomic force microscopy”, Nature Communications (IF : 14.919, Ranking : 4.86%), 7, 11566.
2016 W. Lee, D. Kang, J. Song, J. Moon, and D. Kim, “Controlled unusual stiffness of mechanical metamaterials”, Scientific Reports (IF : 4.380, Ranking : 22.92%), 6, 20312.
2016 J. Kim, J. Song, K, Kim, S. Kim, J. Song, N. Kim, M. Khan, L. Zhang, J. Sader, K. Park, D. Kim, Th. Thundat, and J. Lee, “Hollow microtube resonators via silicon self-assembly toward subattogram mass sensing applications”, Nano Letters (IF : 11.189, Ranking : 9.43%), 16, 1537.
2015 M. Yang, W. Lee, H, Shin, and D. Kim, “Computational analysis for morphological evolution in pyrolysis for micro/nanofabrication”, Journal of Nanomaterials, 2015, 931429.
2015 Y. Shin, J. Song, D. Kim, and T. Kang, "Facile Preparation of Ultrasmall Void Metallic Nanogap from Self-Assembled Gold-Silica Core-Shell Nanoparticles Monolayer via Kinetic Control", Advanced Materials (IF : 30.849, Ranking : 2.54%), 27, 4344. (Selected as Journal Cover)
2015 S. Kim, W. Lee, and D. Kim, “One-step distortion simulation of pulsed laser welding with multi-physics information”, International Journal of Simulation Modelling, 14, 85.
2015 S. Kim, W. Lee, Q. Han, and D. Kim, “Pulsed laser induced mechanical behavior of Zircaloy-4”, Journal of Materials Research, 30, 556.
2015 L. Zhang, S. Kim, and D. Kim, “Multiphysics and Multiscale Analysis for Chemotherapeutic Drug”, BioMed Research International, 2015, 493985.
2015 M. Yang, S. Jung, T. Kang, and D. Kim, “Equilibrium morphology of plasmonic Au/polystyrene dimeric nanoparticle”, The Journal of Physical Chemistry C, 119, 6148.
2014 J. Song, M. Song, T. Kang, D. Kim, L. Lee, “Label-free density difference amplification-based cell sorting”, Biomicrofluidics, 8, 1.
2014 Y. Shin, Ch. Lee, M. Yang, S. Jung, D. Kim, T. Kang, “Two-dimensional hyper-branched gold nanoparticles synthesized on a two-dimensional oil&water interface”, Scientific Reports (IF : 4.380, Ranking : 22.92%), 4, 1.
2014 M. Kim, S. Bang, H. Lee, N. Kim, D. Kim, “Enhancement of dimple formability in sheet metals by 2-step forming”, Materials & Design (IF : 7.991, Ranking : 17.22%), 54, 121.
2014 M. Yang, J. Choi, J. Lee, N. Hur, D. Kim, “Wet blasting as a deburring process for aluminum”, Journal of Materials Processing Technology, 214, 624.
2014 H. Han, J. Song, J. Hong, D. Kim, T. Kang, "Immiscible oil-water interface: dual function of electrokinetic concentration of charged molecules and optical detection with interfacially trapped gold nanorods", Analytical Chemistry (IF : 6.986, Ranking : 8.62%)86, 12, (6160)
2013 J. Song, D. Kim, "Computational kinetic study of chemotactic cell migration", Journal of Applied Physics 114, (154701-1)
2013 L. Zhang, S. Kang, D. Kim, "Molecular Dynamics Simulation of the Interface Energy of Cell Membrane", Journal of Computational and Theoretical Nanoscience 10, (1859)
2013 J. Bae, H. Chung, D. Kim, "Modeling and Simulation Study Based on Corpuscular Particle Method for Side Airbag Design", Journal of Computational and Theoretical Nanoscience 10, (1836)
2013 W. Lee, D. Kim, "Meshless method for the posturing technique of a human body model", Journal of Computational and Theoretical Nanoscience 10, (1819)
2013 M. Yang, J. Choi, J. Lee, N. Hur, D. Kim, "Wet blasting as a deburring process for aluminum", Journal of Material Processing Technology 3, (524)
2012 L. Zhang, S. Kang, D. Kim, "Computational analysis of the effects of matrix-degrading enzymes on cancer-cell invasion", Journal of Applied Physics 112, (124704-1)
2012 H. Chung, S. Kong, and D. Kim, "Study on the Compressive Modulus of Nylon-11/Silica Nanocomposites", Journal of Nanomatrials 2012 (7)
2012 Q. Han, D. Kim, D. Kim, H. Lee and N. Kim, "Laser pulsed welding in thin sheets of Zircaloy-4", Journal of Material Processing Technology 212, 5, (1116)
2011 L. Zhang, J. Song and D. Kim, "A study on the interfacial effect on the cancer-cell invasion", Journal of Applied Physics 109, 074702 (Selected by Virtual Journal in Science & Technology Vol. 21. Apr. 2011)
2011 J. Song and D. Kim, "Development of a three-dimensional dynamic model for chemotaxis", Interaction and Multiscale Mechanics 4, 1.
2011 L. Zhang and D. Kim, "Computational analysis of matrix-degrading enzymes in cancer-cell invasion", BioChip Journal 5, 14.
2010 J. Song and D. Kim, "Three dimensional chemotaxis model for a crawling neutrophil", Physical Review E (IF : 2.529, Ranking : 13.63%), 82, 051902 (Selected by Virtual Journal in Science & Technology Vol. 20. Nov. 2010)
2010 L. Zhang, J. Song and D. Kim, "A study on cancer-cell invasion based on multi-physics analysis technology", BioChip Journal, 4, 161.
2010 J. Song and D. Kim, "Development of three-dimensional haptotaxis model for single crawling cell", BioChip Journal, 4, 184.
2009 D. Kim, "Computational analysis of the interfacial effect on electromigration in flip chip solder joints", Microelectronics Engineering, 86, 2132.
2009 J. H. Song and D. Kim, "Three-dimensional chemotaxis model for a single bacterium", Journal of Computational Theoretical Nanoscience, 6,7.(1687)
2009 D. Kim, “Evolution of micro solder joints under electromigration and elastic field”, Journal of Mechanical Science and Technology, 23, 489.
2008 D. Kim, “Three-dimensional model for electromigration induced evolution of flip chip solder joints”, Journal of Mechanical Science and Technology, 23, 504.
2006 D. Kim and W. Lu, "Creep flow, diffusion, and electromigration in small scale interconnects", Journal of the Mechanics and Physics of Solids (IF : 5.471, Ranking : 7.04%), 54, 2554.
2006 D. Kim and W. Lu, "Interface instability and nanostructure patterning," Computational Materials Science, 38, 418.
2006 W. Lu and D. Kim, "Thin-film structures induced by electrostatic field and substrate kinetic constraint," Applied Physics Letters, 88, 153116.
2006 D. Kim and W. Lu, "Three-dimensional model of electrostatically induced pattern formation in thin polymer films," Physical Review B, 73, 035206.
2005 W. Lu and D. Kim, "Engineering nanophase self-assembly with elastic field," Acta Materialia, 53, 3689.
2005 W. Lu and D. Kim, "Simulation on nanoscale self-assembly of ternary-epilayers," Computational Materials Science (IF : 8.203, Ranking : 15.72%), 32, 20.
2004 D. Kim and W. Lu, "Self-organized nanostructures in multi-phase epilayers," Nanotechnology, 15, 667.
2004 W. Lu and D. Kim, "Patterning nanoscale structures by surface chemistry," Nano Letters (IF : 11.189, Ranking : 9.43%), 4, 313.
2004 W. Lu and D. Kim, "Dynamics of nanoscale self-assembly of ternary epilayers," Microelectronic Engineering, 75, 78.
2004 D. Kim and W. Lu, "Stability of multi-component epilayers and nanopattern formation," Journal of Nanoparticle Research, 6, 495.

Scopus & Domestic

2014 J. Park, S. Kim, and D. Kim, “Design LixV2O5 cathode structure for effective Li-ion intercalation”, Transaction of the Korean Society of Mechanical Engineers, 38, 589.
2013 노상은, 김동철, 손기헌, “분무 증발을 이용한 칩 냉각 향상에 대한 수치적 연구”, 한국전산유체공학회지, 18, 9.
2013 김인숙, 김동철, “종합설계 교과목의 교수-학습 결과 분석”, 공학교육연구, 16, 31.
2013 김하성, 김민수, 이형일, 김낙수, 김동철, “2중 성형에 의한 금속판재 딤플의 성형성 향상”, 대한기계학회논문집 A권, 37, 841.
2013 S. Kim, and D. Kim, “Li-ion diffusion and phase transition in various cathodes of Li-ion battery”, Transaction of the Korean Society of Mechanical Engineers, 37, 665.
2012 최종락, 허남건, 김동철, 김희수, “자동차 도장 건조 공정의건조 성능 향상을 위한 수치해석 연구”, 설비공학 논문집, 24, 867.
2011 J. Song, and D. Kim, “Development of three-dimensional chemotaxis model for a single crawling cell considering the interaction between the cell and substrate”, Transaction of the Korean Society of Mechanical Engineers, 35, 1355.

Conference

2012 송지환, 김동철, "Phase field monel 기반 온도 변화에 따른 형상기억합금의 상변화 연구, 2012 춘계기계학회
2012 L.Zhang, D. Kim, "Molecular dynamics simulation of the diffusion coefficient of chemotherapeutic drug, 2012 춘계기계학회
2012 양명석, 김동철, "열분해 과정을 통한 고분자 화합물의 탄화과정 모사", 2012 춘계기계학회
2012 배지예, 김동철, "측면 에어백 유동 효과를 고려한 corpuscular particle method 기반의 충돌 해석", 2012 한국 자동차 안전학회 춘계학술대회
2011 김수일, 배지예, 이우주, 김동철 "자동화된 해석기법 적용을 통한 차량 에어백 설계 시스템 개발", 2011 한국 자동차공학회 추계학술대회
2011 L. Zhang and D. Kim, "The effect of matrix-degrading enzymes on cancer cell invasion", 2011 춘계기계학회
2011 L. Zhang and D. Kim, "The influence of matrix-degrading enzymes and chemotherapeutic drug on cancer cell invasion and treatment", 2011 추계기계학회
2011 한규헌, 김동철, "변형률 측정 기법을 통한 점용접부의 피로수명 예측", 2011 추계기계학회 (우수논문선정)
2011 송지환, 김동철, "전자기장을 이용한 고분자 박막의 자기조립현상 전산모사 연구", 2011 한국 생산 제조 시스템 학회
2011 김동철, 송지환, "흡착면 패턴에 따른 흡착형 세포의 주화성 연구", 2011 춘계기계학회
2011 송지환, 김동철, "Phase field crystal 모델을 이용한 마이크로구조물의 멀티스케일 모델링", 2011 추계기계학회
2011 L. Zhang, D. Kim "A Computational Study of Chmotherapeutic Drug in Cancer Cell Invasion", The 2011 world congress on Advances in Structure Engineering and Mechanics (ASEM' 11)
2011 D. Kim, Q. Han, S. Gong, H. Kang, C. Shin and T. Lee, "Fatigue Life Prediction of Spot Welds with Direct Strain Measurement" SAE2011 World Congress & Exhibition
2010 J. Song and D. Kim, "Study for the Interfacial Effect between a Crawling Cell and a Substrate on Chemotaxis", 2010 MRS Fall Meeting
2010 J. Song and D. Kim, "Development of three-dimensional chemotaxis model for single crawling cell, considering the interaction between the cell and substrate", 2010 추계기계학회 (우수논문선정)
2010 L. Zhang, J. Song and D. Kim, "A new study primary on the invasive process of cancer cell based on Multi-physics analysis technology", 2010 추계기계학회
2010 L. Zhang, J. Song and D. Kim, "A study on cancer cell invasion with a three-dimensional dynamic multi-physics model", 한국전산유체공학회
2010 L. Zhang, J. Song and D. Kim, "A study on cancer cell invasion based on the diffuse interface model", APME
2010 D. Kim and J. Song, "The phase field model for nano/microstructure evolution", International Conference on Advances in Interaction and Multiscale Mechanics
2009 송지환, 김동철, "계면확산모델을 이용한 백혈구의 주성 연구", 대한기계학회 2009년도 바이오공학부문 춘계학술대회
2009 송지환, 김동철, "3차원 주화성 모델 개발을 통한 흡착형 세포의 동적특성 연구", 2008추계기계학회
2008 D. Kim, R. Mondeza, P. Voorhees, K. Thornton, “Flow in mushy zone using 3D measurement of microstructure,” TMS.
2006 D. Kim and W. Lu, "Simulation of nanostructure formation in thin polymer films," Materials Research Society Symposium Proceedings, 890, 107.
2006 D. Kim and W. Lu, "Evolving thin polymer film driven by electrostatic field," Materials Research Society Symposium Proceedings, 889, 97.
2004 D. Kim and W. Lu, "Engineering monolayers with strain field," American Society of Mechanical Engineers, Materials Division (Publication) MD, 99, 101.
2003 W. Lu and D. Kim, "Guided formation of nanostructures in thin films," Materials Research Society Symposium ? Proceedings, 795, 281.
2003 W. Lu and D. Kim, "Forces that drive self-assembly of ternary epilayer on a solid surface," American Society of Mechanical Engineers, EEP, 3, 803.

Patent

2011 J. Song, L. Zhang and D. Kim "암세포 거동 모델링 방법 및 장치"
2011 J. Song and D. Kim "유영세포의 거동 모델링 방법 및 장치"
2011 J. Song and D. Kim "흡착세포의 거동 모델링 방법 및 장치"
2011 J. Bae, S. Cha, H. Cho, S. Hong and D. Kim "공압 실린더를 이용한 버튼식 자동 상하운동 지하철 열차 선반"
2011 D. Kim "솔더 조인트의 접촉면적의 패턴 형성을 통한 내구성 향상 기술"
2010 Q. Han, D. Kim and T. Lee "스트레인 게이지의 부착 구조물"