Uiler-Lagrange 식을 사용한 확장형 완경사방정식 유도

이창훈(Lee Changhoon),김규한(Kim Kyu-Han) 대한토목학회 2009 대한토목학회논문집 B Vol.29 No.5B

본 연구에서 Euler-Lagrange 식을 사용하여 속도포텐셜로 표현되는 확장형 완경사방정식을 유도하였다. 먼저, Euler-Lagrange 식을 사용하여 흐름함수로 표현된 확장형 완경사방정식을 유도한 Kim과 Bai(2004)의 유도과정을 따라가면서 속도표텐셜로 표현된 확장형 완경사방정식과의 관계를 찾았다. 속도포텐셜로 표현된 Euler-Lagrange 식을 찾아낸 다음 고차의 수심변화 항을 유도하였다. 본 연구에서 유도된 확장형 완경사방정식은 기존의 식인 Massel(1993)의 식과 Chamberlain과 Porter(1995)의 식과 정확히 일치하였다. 본 연구의 연구 성과는 확장형 완경사방정식의 유도 방법을 새로 제시하여 해안공학의 영역을 넓히는데 의의가 있다. In this study, we derive the extended mild-slope equation in terms of the velocity potential using the Euler-Lagrange equation. First, we follow Kim and Bai (2004) who derive the complementary mild-slope equation in terms of the stream function using the Euler-Lagrange equation and we compare their equation to the existing extended mild-slope equations of the velocity potential. Second, we derive the extended mild-slope equation in terms of the velocity potential using the Euler-Lagrange equation. In the developed equation, the higher-order bottom variation terms are newly developed and found to be the same as those of Massel (1993) and Chamberlain and Porter (1995). The present study makes wide the area of coastal engineering by developing the extended mild-slope equation with a way which has never been used before.

Chemoradiotherapy versus radiotherapy alone following induction chemotherapy for elderly patients with stage III lung cancer

Kim, Dong-Yun,Song, Changhoon,Kim, Se Hyun,Kim, Yu Jung,Lee, Jong Seok,Kim, Jae-Sung The Korean Society for Radiation Oncology 2019 Radiation Oncology Journal Vol.37 No.3

Purpose: It is unclear whether adding concurrent chemotherapy (CT) to definitive radiotherapy (RT) following induction CT is a tolerable and cost effective treatment for non-small-cell lung cancer (NSCLC) patients aged 70 years or older with comorbidities. This study evaluated the actual clinical outcomes between concurrent chemoradiotherapy (CCRT) and RT alone following induction CT or not in patients (≥70 years) in a single institution's clinical practice. Materials and Methods: A total of 82 patients with unresectable stage III NSCLC between 2004 and 2016 were retrospectively analyzed. Their treatment tolerance and clinical outcomes such as overall survival (OS), locoregional recurrence (LRR), treatment toxicities and distant metastasis (DM) were evaluated. Early mortality rates were also evaluated as 4-month mortality after RT. Results: Fifty-four patients received CCRT and 28 patients received RT alone. Induction CT before RT was performed for 68.5% and 50.0% in CCRT and RT alone groups. Treatment tolerance was significantly worse in CCRT (p = 0.046). The median survival was 21.1 and 18.1 months for CCRT and RT alone, which was not statistically significant. LRR and DM were also not different. Most early deaths after CCRT were attributed to non-cancer-related mortality. Acute esophagitis of grade ≥2 occurred more following CCRT (p = 0.017). In multivariate analysis, a Charlson Comorbidity Index (CCI) of ≥5 and a weight loss of ≥5% after RT were associated with poor OS. The factors adversely affecting 4-month survival were a CCI of ≥5 and CCRT. Conclusion: There were no significant differences in OS, LRR, and DM between CCRT and RT alone treatment in elderly patients. However, there was a poorer tolerance and higher incidence of acute esophagitis in the CCRT group. Specifically, when the patients had a CCI of ≥5, RT alone seems to be reasonable with a low probability of early death.

Graphene Oxide Assisted Synthesis of Self-assembled Zinc Oxide for Lithium-Ion Battery Anode

Kim, Chungho,Kim, Jin Wook,Kim, Hyunhong,Kim, Dong Hyeon,Choi, Changhoon,Jung, Yoon Seok,Park, Jongnam American Chemical Society 2016 Chemistry of materials Vol.28 No.23

<P>A simple method for the synthesis of a hierarchically self-assembled zinc oxide is presented, in which graphene oxide is used to assist in the assembly of the structure and improve the electrical conductivity of the ZnO. The self-assembled ZnO formed on graphene oxide exhibits a high specific capacity, while also demonstrating good rate performance and cycling stability due to the advantages of using both nanoparticles and a secondary structure.</P>

Progressive Dehazing and Depth Estimation from a Single Hazy Image

Jeonghoon Kim,Sungyoon Kim,Changhoon Pyo,Hyeongmyeon Kim,Changhoon Yim 대한전자공학회 2022 IEIE Transactions on Smart Processing & Computing Vol.11 No.5

We propose a progressive dehazing and depth estimation (PDDE) method with optimal estimation of the attenuation coefficient. We investigated the characteristics of dehazing operations related to the depth and attenuation coefficient for PDDE. Entropy was used as a non-reference image quality metric for optimality assessment of dehazed images. The proposed PDDE method provides an optimal dehazed image and depth estimation from a single hazy image. Experimental results show that the proposed method provides clearer and subjectively better results for single image dehazing than previous image dehazing methods. It also results in a significant improvement in the accuracy of depth estimation from a single hazy image compared with previous depth estimation methods.

시멘트 분진 노출 대상자 분류 모형을 활용하여 미세먼지 노출 연관성 해석

김현진(Hyeonjin Kim),김태우(Taewoo Kim),김우진(Woo Jin Kim),이창훈(Changhoon Lee),최지웅(Jiwoong Choi),김경남(Kyoung-Nam Kim),채금주(Kum Ju Chae),진공용(Gong Yong Jin),이창현(Chang Hyun Lee),최상헌(Sanghun Choi) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

블루투스를 이용한 이중인증방식의 전자지불 시스템의 개발

김성일(Sungill Kim),김용민(Yongmin Kim),김현익(Hyunik Kim),정창훈(Changhoon Jung),김응규(Eungkyeu Kim) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.2Ⅰ

최근 전자상거래의 활성화와 더불어 기존의 유선인터넷에서 사용하고 있는 전자지갑 (S/W)등 전자상거래 방식에서 Smart Cαrd 나 이동통신 단말기와 같은 독립적인 유/ 무선 단일을 사용하는 전자지불 시스템에 대한 관심이 고조되고 있다. 본 연구에서는 전자지불 시스템에 Bluetooth를 이용하여 안전한 사용자 인증 및 종단간의 보안을 제공 전자화폐의 발행/지불이 가능한 전자지불 시스템의 모델을 제시하고자 한다. 각 단일의 서브셋(subset)으로 Bluetooth 컨트롤 시스템과 이를 이용하는 전자지불 시스템으로서 전자지갑 및 전자화폐 발행기/자동판매기를 구현하여 각각의 보안 통신과 전자화폐의 발행/지불이 가능함을 나타냈다. 구현 결과물은 실제 전자지불 시스템에 적용이 가능할 것으로 보인다.

Chemoradiotherapy versus radiotherapy alone following induction chemotherapy for elderly patients with stage III lung cancer

Dong-Yun Kim,Changhoon Song,Se Hyun Kim,Yu Jung Kim,Jong Seok Lee,Jae-Sung Kim 대한방사선종양학회 2019 Radiation Oncology Journal Vol.37 No.3

Purpose: It is unclear whether adding concurrent chemotherapy (CT) to definitive radiotherapy (RT) following induction CT is a tolerable and cost effective treatment for non-small-cell lung cancer (NSCLC) patients aged 70 years or older with comorbidities. This study evaluated the actual clinical outcomes between concurrent chemoradiotherapy (CCRT) and RT alone following induction CT or not in patients (≥70 years) in a single institution’s clinical practice. Materials and Methods: A total of 82 patients with unresectable stage III NSCLC between 2004 and 2016 were retrospectively analyzed. Their treatment tolerance and clinical outcomes such as overall survival (OS), locoregional recurrence (LRR), treatment toxicities and distant metastasis (DM) were evaluated. Early mortality rates were also evaluated as 4-month mortality after RT. Results: Fifty-four patients received CCRT and 28 patients received RT alone. Induction CT before RT was performed for 68.5% and 50.0% in CCRT and RT alone groups. Treatment tolerance was significantly worse in CCRT (p = 0.046). The median survival was 21.1 and 18.1 months for CCRT and RT alone, which was not statistically significant. LRR and DM were also not different. Most early deaths after CCRT were attributed to non-cancer-related mortality. Acute esophagitis of grade ≥2 occurred more following CCRT (p= 0.017). In multivariate analysis, a Charlson Comorbidity Index (CCI) of ≥5 and a weight loss of ≥5% after RT were associated with poor OS. The factors adversely affecting 4-month survival were a CCI of ≥5 and CCRT. Conclusion: There were no significant differences in OS, LRR, and DM between CCRT and RT alone treatment in elderly patients. However, there was a poorer tolerance and higher incidence of acute esophagitis in the CCRT group. Specifically, when the patients had a CCI of ≥5, RT alone seems to be reasonable with a low probability of early death.

Recovering Leadership through Preaching - Suggestions for Recovering the Power of Preaching

Changhoon Kim Presbyterian General Assembly Theological Seminary 2016 CHONGSHIN THEOLOGICAL JOURNAL Vol.21 No.-

In this study, I discuss what is required to recover the power of preaching from the perspective of a preacher. I attempt to present my view in two broad categories of the essential requirements and the preparation and the content of sermon. Of course, there are a number of requirements, which could be discussed from various aspects. However, due to the limit of space, I make my points and suggestions only very briefly. In summation, what is required of a preacher to restore the power of preaching is to solely depend on the Lord’s provision and guidance. Also, it is necessary for one to do his best in preparing a sermon that would please God and that is communicated the most effectively. I hope that this paper could offer a new challenge and practical help to the preachers and that the restored pulpit could contribute to transforming the crumbling Korean church to make a leap forward.

Dosimetric and Radiobiological Evaluation of Dose Volume Optimizer (DVO) and Progressive Resolution Optimizer (PRO) Algorithm against Photon Optimizer on IMRT and VMAT Plan for Prostate Cancer

Kim, Yon-Lae,Chung, Jin-Beom,Kang, Seong-Hee,Eom, Keun-Yong,Song, Changhoon,Kim, In-Ah,Kim, Jae-Sung,Lee, Jeong-Woo Korean Society of Medical Physics 2018 의학물리 Vol.29 No.4

This study aimed to compare the performance of previous optimization algorithms against new a photon optimizer (PO) algorithm for intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans for prostate cancer. Eighteen patients with prostate cancer were retrospectively selected and planned to receive 78 Gy in 39 fractions of the planning target volume (PTV). All plans for each patient optimized with the dose volume optimizer (DVO) and progressive resolution optimizer (PRO) algorithms for IMRT and VMAT were compared against plans optimized with the PO within Eclipse version 13.7. No interactive action was performed during optimization. Dosimetric and radiobiological indices for the PTV and organs at risk were analyzed. The monitor units (MU) per plan were recorded. Based on the plan quality for the target coverage, prostate IMRT and VMAT plans using the PO showed an improvement over DVO and PRO. In addition, the PO generally showed improvement in the tumor control probability for the PTV and normal tissue control probability for the rectum. From a technical perspective, the PO generated IMRT treatment plans with fewer MUs than DVO, whereas it produced slightly more MUs in the VMAT plan, compared with PRO. The PO showed over potentiality of DVO and PRO whenever available, although it led to more MUs in VMAT than PRO. Therefore, the PO has become the preferred choice for planning prostate IMRT and VMAT at our institution.

Association Between Expression Level of PD1 by Tumor-Infiltrating CD8⁺ T Cells and Features of Hepatocellular Carcinoma

Kim, Hyung-Don,Song, Gi-Won,Park, Seongyeol,Jung, Min Kyung,Kim, Min Hwan,Kang, Hyo Jeong,Yoo, Changhoon,Yi, Kijong,Kim, Kyung Hwan,Eo, Sukyeong,Moon, Deok-Bog,Hong, Seung-Mo,Ju, Young Seok,Shin, Eui- Elsevier 2018 Gastroenterology Vol.155 No.6

<P><B>Background & Aims</B></P> <P>T-cell exhaustion, or an impaired capacity to secrete cytokines and proliferate with overexpression of immune checkpoint receptors, occurs during chronic viral infections but has also been observed in tumors, including hepatocellular carcinomas (HCCs). We investigated features of exhaustion in CD8<SUP>+</SUP> T cells isolated from HCC specimens.</P> <P><B>Methods</B></P> <P>We obtained HCC specimens, along with adjacent nontumor tissues and blood samples, from 90 patients who underwent surgical resection at Asan Medical Center (Seoul, Korea) from April 2016 through April 2018. Intrahepatic lymphocytes and tumor-infiltrating T cells were analyzed by flow cytometry. Tumor-infiltrating CD8<SUP>+</SUP> T cells were sorted by flow cytometry into populations based on expression level of programmed cell death 1 (PDCD1 or PD1): PD1-high, PD1-intermediate, and PD1-negative. Sorted cells were analyzed by RNA sequencing. Proliferation and production of interferon gamma (IFNG) and tumor necrosis factor (TNF) by CD8<SUP>+</SUP> T cells were measured in response to anti-CD3 and antibodies against immune checkpoint receptors including PD1, hepatitis A virus cellular receptor 2 (HAVCR2 or TIM3), lymphocyte activating 3 (LAG3), or isotype control. Tumor-associated antigen-specific CD8<SUP>+</SUP> T cells were identified using HLA-A*0201 dextramers. PDL1 expression on tumor tissue was assessed by immunohistochemistry.</P> <P><B>Results</B></P> <P>PD1-high, PD1-intermediate, and PD1-negative CD8<SUP>+</SUP> T cells from HCCs had distinct gene expression profiles. PD1-high cells expressed higher levels of genes that regulate T-cell exhaustion than PD1-intermediate cells. PD1-high cells expressed TIM3 and LAG3, and low proportions of TCF1<SUP>+</SUP>, TBET<SUP>high</SUP>/eomesodermin<SUP>low</SUP>, and CD127<SUP>+</SUP>. PD1-high cells produced the lowest amounts of IFNG and TNF upon anti-CD3 stimulation. Differences in the PD1 expression patterns of CD8<SUP>+</SUP> T cells led to the identification of 2 subgroups of HCCs: HCCs with a discrete population of PD1-high cells were more aggressive than HCCs without a discrete population of PD1-high cells. HCCs with a discrete population of PD1-high cells had higher levels of predictive biomarkers of response to anti-PD1 therapy. Incubation of CD8<SUP>+</SUP> T cells from HCCs with a discrete population of PD1-high cells with antibodies against PD1 and TIM3 or LAG3 further restored proliferation and production of IFNG and TNF in response to anti-CD3.</P> <P><B>Conclusions</B></P> <P>We found HCC specimens to contain CD8<SUP>+</SUP> T cells that express different levels of PD1. HCCs with a discrete population of PD1-high CD8<SUP>+</SUP> T cells express TIM3 and/or LAG3 and produce low levels of IFNG and TNF in response to anti-CD3. Incubation of these cells with antibodies against PD1 and TIM3 or LAG3 further restore proliferation and production of cytokines; HCCs with a discrete population of PD1-high CD8<SUP>+</SUP> T cells might be more susceptible to combined immune checkpoint blockade–based therapies.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>