Numerical Method for Achieving Smoothness of Fracture Plane and Minimizing Overbreak in Tunnel-Blasting

Daisuke FUKUDA,Katsuhiko KANEKO,Koji ISHIYAMA,Masashi NAITOH,Sang Ho CHO 한국암반공학회 2009 한국암반공학회 학술대회 및 세미나 자료집 Vol.2009 No.10

Efficacy and Safety of Trastuzumab Deruxtecan and Nivolumab as Third- or Later-Line Treatment for HER2-Positive Advanced Gastric Cancer: A Single-Institution Retrospective Study

Daisuke Takahari,Keitaro Shimozaki,Izuma Nakayama,Kengo Nagashima,Koichiro Yoshino,Koshiro Fukuda,Shota Fukuoka,Hiroki Osumi,Mariko Ogura,Takeru Wakatsuki,Akira Ooki,Eiji Shinozaki,Keisho Chin,Kensei 대한위암학회 2023 Journal of gastric cancer Vol.23 No.4

Purpose: Determination of optimal treatment strategies for HER2-positive advanced gastric cancer (AGC) in randomized trials is necessary despite difficulties in direct comparison between trastuzumab deruxtecan (T-DXd) and nivolumab as third or later-line treatments. Materials and Methods: This single-institution, retrospective study aimed to describe the real-world efficacy and safety of T-DXd and nivolumab as ≥ third line treatments for HER2-positive AGC between March 2016 and May 2022. Overall, 58 patients (median age, 64 years; 69% male) were eligible for the study (T-DXd group, n=20; nivolumab group, n=38). Results: Most patients exhibited a HER2 3+ status (72%) and presented metastatic disease at diagnosis (66%). The response rates of 41 patients with measurable lesions in the T-DXd and nivolumab groups were 50% and 15%, respectively. The T-DXd and nivolumab groups had a median progression-free survival of 4.8 months (95% confidence interval [CI], 3.3, 7.0) and 2.3 months (95% CI, 1.5, 3.5), median overall survival (OS) of 10.8 months (95% CI, 6.9, 23.8) and 11.7 months (95% CI, 7.6, 17.1), and grade 3 or greater adverse event rates of 50% and 2%, respectively. Overall, 64% patients received subsequent treatment. Among 23 patients who received both regimens, the T-DXd–nivolumab and nivolumab–T-DXd groups had a median OS of 14.0 months (95% CI, 5.0, not reached) and 19.3 months (95% CI, 9.5, 25.1), respectively. Conclusions: T-DXd and nivolumab showed distinct efficacy and toxicity profiles as ≥ third line treatments for HER2-positive AGC. Considering the distinct features of each regimen, they may help clinicians personalize optimal treatment approaches for these patients.

발파 암반-콘크리트 경계면에서의 전단거동특성에 대한 수치해석적 연구

민경조,고영훈,Daisuke fukuda,오세욱,김정규,정문경,조상호 대한화약발파공학회 2019 화약발파 Vol.37 No.4

In designing a gravity-type anchorage of earth-anchored suspension bridge, the contact friction between a blasted rock mass and the concrete anchorage plays a key role in the stability of the entire anchorage. Therefore, it is vital to understand the shear behavior of the interface between the blasted rock mass and concrete. In this study, a portable 3D LiDAR scanner was utilized to scan the blasted bottom surfaces, and rock surface roughness was quantitatively analyzed from the scanned profiles to apply to 3D FEM modelling. In addition, based on the 3D FEM model, a three-dimensional dynamic fracture process analysis (DFPA-3D) technique was applied to study on the shear behavior of the interface between blasted rock and concrete through direct shear tests, which was analyzed under constant normal load (CNL). The effects of normal stress and the joint roughness on shear failure behavior are also analyzed. 타정식 현수교의 중력식 앵커리지를 설계하는 데 있어, 지반과 콘크리트 앵커블록 사이에 작용하는 접촉마찰력은 교량의 주케이블의 장력을 지지하는데 많은 기여를 하고 있기 때문에 콘크리트와 암반 사이 접촉면의마찰 및 전단 저항 특성을 이해하는 것이 중요하다. 이를 위해, 본 연구에서는 휴대용 레이저 스캐너를 활용하여발파 바닥면을 스캐닝하였으며, 이를 바탕으로 3차원 모델링 및 거칠기를 정량적으로 분석하였다. 또한 발파 바닥암반 단면 데이터를 활용하여, 발파 바닥암반-콘크리트 경계면을 갖는 모델을 생성하였다. 동적파괴과정해석기법(DFPA-3D)를 활용하여, 해당 모델에 대한 직접 전단시험 모사를 수행하였으며, 이를 바탕으로 발파 바닥암반- 콘크리트 접촉면에 대한 전단파괴 거동을 확인 및 분석하였다.

Numerical Study of Fracture Process on Full-Scale Concrete Foundations by Means of Controlled Blast Method Utilizing Galvanized Steel Charge Holders

Kim, Hakman,Fukuda, Daisuke,Kaneko, Katsuhiko,Lee, Juhyung,Cho, Sang-ho Trans Tech Publications 2017 Key Engineering Materials Vol.744 No.-

<P> Mechanical breakage systems are generally employed to demolish a portion of a concrete building, however it is time consuming and costly. And the mechanical demolition work involves various risks such as those associated with occupational safety and presents a noise hazard to the general public living in the vicinity. Therefore, alternative methods for such work have been sought. For this purpose, a dynamic breakage system utilizing diamond-shaped charge holders was proposed to rapidly remove the desired portion of the concrete foundation. The charge holders which initiate crack growth were placed inside a concrete mass along the desired fracture plane. In this study, full-scale blast experiments utilizing the charge holders were introduced and the roughness of fracture planes was observed using a 3-dimensional photography system. In order to verify the effect of the charge holders on fracture controlling in full-scale blast experiments, the fracture processes of the concrete blocks were analyzed using the dynamic fracture process analysis (DFPA) code. The mechanism required to achieve controlled breakage was discussed after taking into account the influence of various loading conditions and crack tip velocity. It was found that the DFPA tool is a useful instrument in the analysis of full scale blast experiments. </P>

산업용 연돌 발파해체에서 붕괴거동에 관한 수치해석적 연구

전푸른,민경조,Daisuke Fukuda,박 훈,석철기,송태협,장경필,조상호 대한화약발파공학회 2023 화약발파 Vol.41 No.3

1970년대 산업화에 따른 플랜트 구조물이 노후화됨에 따라 구조적 기능을 상실해 발파 해체 공법을 활용한 해체 철거 수요가 증가하고 있다. 발파 해체공법은 기계식 해체공법에 비해 해체 공기가 짧아 환경공해 발생 노출 시간을 최소화할 수 있지만 잘못된 발파 설계 및 시공 계획에 따른 붕괴거동의 실패는 안전성에 매우 큰 위험을 유발한다. 따라서 붕괴거동 모사를 통해 최적의 발파 해체 조건과 이에 따른 영향을 고려하는 것이 중요하다. 본 연구에서는 Finite element method (FEM)와 Discrete element method (DEM)의 장점을 활용해 구축된 3-D Combined finite discrete element method (FDEM) 코드 기반 3-D DFPA 를 적용해 (구)서천화력발전소의 연돌 구조 물에 대한 해체 모사를 수행하였으며 실제 구조물의 연돌 구조물 발파해체의 붕괴거동과 비교 분석하였다. 수치 모사 결과, 실제 구조물과 붕괴 거동 및 붕괴 완료 시간이 동일하게 나타났다. 또한, 발파구간 개구부 상부에 위 치한 후드부의 크기가 연돌의 붕괴거동에 미치는 영향을 분석하기 위해 후드부의 면적을 조정하여 해체 모사를 수행하고 균열 발생 양상 및 z-방향 변위 곡선을 통해 비교 분석하였다. 분석 결과, 후드부의 면적이 증가함에 따라 하중을 지지하는 면적이 줄어들고 그에 따른 균열 발생 증가 및 전도 시간 감소를 확인하였다.

Elasto-plastic analysis of rock slope with geological discontinuity

Atsushi Sainoki,Daisuke Fukuda,Katsuhiko Kaneko,Junichi Kodama 한국암반공학회 2009 한국암반공학회 학술대회 및 세미나 자료집 Vol.2009 No.10

Malnutrition and inflammation status in nonobese patients with inflammatory bowel disease are associated with nonalcoholic fatty liver disease: a retrospective study

Takahiro Nagata,Sadahiro Funakoshi,Daisuke Morihara,Satoshi Shakado,Keiji Yokoyama,Kazuhide Takata,Takashi Tanaka,Atsushi Fukunaga,Ryo Yamauchi,Hiromi Fukuda,Hiroki Matsuoka,So Imakiire,Hideto Sakisak 대한장연구학회 2023 Intestinal Research Vol.21 No.4

Background/Aims: The frequency and details of nonalcoholic fatty liver disease (NAFLD) complications in patients with inflammatory bowel disease (IBD) remain unclear. This study aimed to clarify characteristics of NAFLD in patients with IBD.Methods: We retrospectively identified and enrolled patients with IBD diagnosed with or without NAFLD by undergoing abdominal computed tomography (CT) at our institution between 2005 and 2020. The primary endpoint was the complication rate of NAFLD in patients with IBD. Secondary endpoints were the clinical characteristics of nonobese patients with IBD and comorbid NAFLD and their association with nutritional and inflammatory parameters.Results: Twenty-one (21.9%) of 96 eligible patients with IBD also had NAFLD. In nonobese patients (defined as patients with a body mass index <25 kg/m²), C-reactive protein (CRP; <i>P</i><0.001) and alanine aminotransferase (<i>P</i>=0.018) levels were higher and the albumin level (<i>P</i>=0.005) and prognostic nutritional index (PNI; <i>P</i>=0.002) values were lower in patients with NAFLD than in those without NAFLD. The PNI value was positively correlated (<i>P</i><0.001) and the CRP level was negatively correlated (<i>P</i>=0.001) with the hepatosplenic ratio. However, in the NAFLD combined group, PNI (<i>P</i><0.05) and CRP values (<i>P</i><0.001) were improved over time after CT imaging by continuing IBD treatment.Conclusions: Worsening nutritional and inflammatory status in IBD patients is associated with complications of NAFLD. Diagnosis of NAFLD in IBD patients using CT imaging might be useful not only for early detection of NAFLD but also in assessing the need for therapeutic intervention for IBD.

파라핀 지관 구조체를 활용한 Air-Deck 발파공법의 파쇄입도 및 지반 진동 저감 분포 특성에 관한 수치해석적 연구

신찬휘,김영근,민경조,Daisuke Fukuda,조상호 대한화약발파공학회 2023 화약발파 Vol.41 No.2

The growing need for urban underground excavation has led to an increased focus on efficient and economical blasting methods. In this regard, the recently proposed Air-Deck blasting method, which utilizes a pariffin-waxed paper tube, has been proven to improve the granularity of fractures compared to the conventional blasting method through previous studies. However, the understanding of the fracture process and mechanism of the method is still insufficient. Therefore, in this study, a Hybrid FDEM-based three dimensional dynamic fracture process analysis (3D-DFPA) technique was used to numerically simulate the results of previously studied field experiments, and the process of rock fracture by blasting load was compared and analyzed. As a result, it was found that the fragment distribution generated by blasting was reduced by up to 22.8% and the fragment uniformity was improved by 12.1% when the PA-Deck blasting method was used. 도심 지역의 지하 굴착 작업이 증가함에 따라, 효율적이고 경제적인 발파공법에 대한 연구가 활발히 진행 되고 있다. 이와 관련하여 최근 제안된 파라핀 지관을 활용한 Air-Deck 발파공법은 선행 연구를 통하여 기존 발 파공법에 비해 파쇄입도 향상 효과가 있음을 입증하였으나, 공법의 파괴 과정과 메커니즘에 대한 이해는 아직 미 흡한 실정이다. 따라서, 본 연구에서는 Hybrid FDEM 기반 3차원 동적 파괴과정 해석 기법을 활용하여 선행 연구 된 현장 실험 결과를 수치해석적으로 모사했으며, 발파 하중에 의한 암반 파괴 과정을 비교 분석하였다. 그 결과, PA-Deck 발파공법을 사용하였을 때 발파에 의해 발생하는 파쇄입도는 최대 22.8% 감소하였으며, 입도 균일성은 12.1% 향상되는 것을 확인하였다.

Numerical Study on the Reduction of Blast-induced Damage Zone around Contour Holes

박세웅,오세욱,민경조,Daisuke fukuda,조상호 대한화약발파공학회 2019 화약발파 Vol.37 No.3

Controlling the blast-induced damage zone(BDZ) in mining excavation is a significant issue for the safety of employees and the maintenance of facilities. Numerous studies have been conducted to accurately predict the BDZ in underground mining. This study employed the dynamic fracture process analysis (DFPA) to estimate the BDZ from a single hole blasting. The estimated BDZ were compared with the results obtained by Swedish empirical equation. The DFPA was also used to investigate the control mechanism of BDZ and fracture plane formation around perimeter holes for underground mining blasting.

충격 하중 시 암석의 파괴거동해석을 위한 GPGPU 기반 3차원 동적해석기법의 개발과 검증 연구

민경조 ( Gyeong-jo Min ),( Daisuke Fukuda ),오세욱 ( Se-wook Oh ),조상호 ( Sang-Ho Cho ) 대한화약발파공학회 2021 화약발파 Vol.39 No.2

최근에는 GPGPU(General-Purpose computing on Graphics Processing Units)와 같은 고성능 연산장치의 보급과 함께 국방, 우주항공분야에서 암질재료에 대한 충격실험을 대신할 수 있는 3차원 동적해석기법의 개발이 활발하게 진행되고 있다. 그러나 높은 충격하중을 수반하는 암 발파 또는 소형미사일 등의 지중 관통과 같은 과정을 실험적으로 관찰하거나 계측하는 것은 암질재료의 비 균질성 및 불투명성 때문에 어려움이 있었다. 본 연구에서는 고속충돌에 의한 암석의 파괴 거동을 모사하기 위하여 3차원 동적 파괴 과정 해석 기법 (3D-DFPA)를 개발하였으며, 연산속도를 향상시키기 위하여 순차해석(explicity analysis) 및 접촉요소검색(Searching algolitm of contact elements)에 GPGPU연산이 가능한 알고리듬을 적용하였다. 제안된 동적파괴과정해석 기법에 대한 검증을 위해 Straight Notched Disk Bending (SNDB) 석회암시료에 대한 동적파괴인성시험을 모사하였고, 충격응력파의 전파과정, 암석-충격봉 경계면에서 반사 및 전달과정, 암석 시료의 파괴과정을 비교분석하여, 개발된 해석기법에 대한 검증을 수행하였다. Recently, with the development of high-performance processing devices such as GPGPU, a three-dimensional dynamic analysis technique that can replace expensive rock material impact tests has been actively developed in the defense and aerospace fields. Experimentally observing or measuring fracture processes occurring in rocks subjected to high impact loads, such as blasting and earth penetration of small-diameter missiles, are difficult due to the inhomogeneity and opacity of rock materials. In this study, a three-dimensional dynamic fracture process analysis technique (3D-DFPA) was developed to simulate the fracture behavior of rocks due to impact. In order to improve the operation speed, an algorithm capable of GPGPU operation was developed for explicit analysis and contact element search. To verify the proposed dynamic fracture process analysis technique, the dynamic fracture toughness tests of the Straight Notched Disk Bending (SNDB) limestone samples were simulated and the propagation of the reflection and transmission of the stress waves at the rock-impact bar interfaces and the fracture process of the rock samples were compared. The dynamic load tests for the SNDB sample applied a Pulse Shape controlled Split Hopkinson presure bar (PS-SHPB) that can control the waveform of the incident stress wave, the stress state, and the fracture process of the rock models were analyzed with experimental results.