• 정보보호학회논문지
• /
• 제33권6호
• /
• pp.1099-1110
• /
• 2023

자율주행 및 robot navigation의 인식 시스템은 성능 향상을 위해 다중 센서를 융합(Multi-Sensor Fusion)을 한 후, 객체 인식 및 추적, 차선 감지 등의 비전 작업을 한다. 현재 카메라와 라이다 센서의 융합을 기반으로 한 딥러닝 모델에 대한 연구가 활발히 이루어지고 있다. 그러나 딥러닝 모델은 입력 데이터의 변조를 통한 적대적 공격에 취약하다. 기존의 다중 센서 기반 자율주행 인식 시스템에 대한 공격은 객체 인식 모델의 신뢰 점수를 낮춰 장애물 오검출을 유도하는 데에 초점이 맞춰져 있다. 그러나 타겟 모델에만 공격이 가능하다는 한계가 있다. 센서 융합단계에 대한 공격의 경우 융합 이후의 비전 작업에 대한 오류를 연쇄적으로 유발할 수 있으며, 이러한 위험성에 대한 고려가 필요하다. 또한 시각적으로 판단하기 어려운 라이다의 포인트 클라우드 데이터에 대한 공격을 진행하여 공격 여부를 판단하기 어렵도록 한다. 본 연구에서는 이미지 스케일링 기반 카메라-라이다 융합 모델(camera-LiDAR calibration model)인 LCCNet 의 정확도를 저하시키는 공격 방법을 제안한다. 제안 방법은 입력 라이다의 포인트에 스케일링 공격을 하고자 한다. 스케일링 알고리즘과 크기별 공격 성능 실험을 진행한 결과 평균 77% 이상의 융합 오류를 유발하였다.

• Korean Journal of Radiology
• /
• 제24권5호
• /
• pp.384-394
• /
• 2023

Objective: Mammographic density is an independent risk factor for breast cancer that can change after neoadjuvant chemotherapy (NCT). This study aimed to evaluate percent changes in volumetric breast density (ΔVbd%) before and after NCT measured automatically and determine its value as a predictive marker of pathological response to NCT. Materials and Methods: A total of 357 patients with breast cancer treated between January 2014 and December 2016 were included. An automated volumetric breast density (Vbd) measurement method was used to calculate Vbd on mammography before and after NCT. Patients were divided into three groups according to ΔVbd%, calculated as follows: Vbd (post-NCT - pre-NCT)/pre-NCT Vbd × 100 (%). The stable, decreased, and increased groups were defined as -20% ≤ ΔVbd% ≤ 20%, ΔVbd% < -20%, and ΔVbd% > 20%, respectively. Pathological complete response (pCR) was considered to be achieved after NCT if there was no evidence of invasive carcinoma in the breast or metastatic tumors in the axillary and regional lymph nodes on surgical pathology. The association between ΔVbd% grouping and pCR was analyzed using univariable and multivariable logistic regression analyses. Results: The interval between the pre-NCT and post-NCT mammograms ranged from 79 to 250 days (median, 170 days). In the multivariable analysis, ΔVbd% grouping (odds ratio for pCR of 0.420 [95% confidence interval, 0.195-0.905; P = 0.027] for the decreased group compared with the stable group), N stage at diagnosis, histologic grade, and breast cancer subtype were significantly associated with pCR. This tendency was more evident in the luminal B-like and triple-negative subtypes. Conclusion: ΔVbd% was associated with pCR in breast cancer after NCT, with the decreased group showing a lower rate of pCR than the stable group. Automated measurement of ΔVbd% may help predict the NCT response and prognosis in breast cancer.

• Korean Journal of Radiology
• /
• 제23권5호
• /
• pp.539-547
• /
• 2022

Objective: To investigate the association between functional tumor burden of peritoneal carcinomatosis (PC) derived from diffusion-weighted imaging (DWI) and overall survival in patients with advanced ovarian carcinoma (OC). Materials and Methods: This prospective study was approved by the local research ethics committee, and informed consent was obtained. Fifty patients (mean age ± standard deviation, 57 ± 12 years) with stage III-IV OC scheduled for primary or interval debulking surgery (IDS) were recruited between June 2016 and December 2021. DWI (b values: 0, 400, and 800 s/mm²) was acquired with a 16-channel phased-array torso coil. The functional PC burden on DWI was derived based on K-means clustering to discard fat, air, and normal tissue. A score similar to the surgical peritoneal cancer index was assigned to each abdominopelvic region, with additional scores assigned to the involvement of critical sites, denoted as the functional peritoneal cancer index (fPCI). The apparent diffusion coefficient (ADC) of the largest lesion was calculated. Patients were dichotomized by immediate surgical outcome into high- and low-risk groups (with and without residual disease, respectively) with subsequent survival analysis using the Kaplan-Meier curve and log-rank test. Multivariable Cox proportional hazards regression was used to evaluate the association between DWI-derived results and overall survival. Results: Fifteen (30.0%) patients underwent primary debulking surgery, and 35 (70.0%) patients received neoadjuvant chemotherapy followed by IDS. Complete tumor debulking was achieved in 32 patients. Patients with residual disease after debulking surgery had reduced overall survival (p = 0.043). The fPCI/ADC was negatively associated with overall survival when accounted for clinicopathological information with a hazard ratio of 1.254 for high fPCI/ADC (95% confidence interval, 1.007-1.560; p = 0.043). Conclusion: A high DWI-derived functional tumor burden was associated with decreased overall survival in patients with advanced OC.

• Korean Journal of Radiology
• /
• 제23권2호
• /
• pp.159-171
• /
• 2022

Objective: This study aimed to investigate the impact of baseline values and temporal changes in body composition parameters, including skeletal muscle index (SMI) and visceral adipose tissue area (VAT), measured using serial computed tomography (CT) imaging on the prognosis of operable breast cancers in Asian patients. Materials and Methods: This study retrospectively included 627 Asian female (mean age ± standard deviation [SD], 53.6 ± 8.3 years) who underwent surgery for stage I-III breast cancer between January 2011 and September 2012. Body composition parameters, including SMI and VAT, were semi-automatically calculated on baseline abdominal CT at the time of diagnosis and follow-up CT for post-treatment surveillance. Serial changes in SMI and VAT were calculated as the delta values. Multivariable Cox regression analysis was used to evaluate the association of baseline and delta SMI and VAT values with disease-free survival. Results: Among 627 patients, 56 patients (9.2%) had breast cancer recurrence after a median of 40.5 months. The mean value ± SD of the baseline SMI and baseline VAT were 43.7 ± 5.8 cm²/m² and 72.0 ± 46.0 cm², respectively. The mean value of the delta SMI was -0.9 cm²/m² and the delta VAT was 0.5 cm². The baseline SMI and VAT were not significantly associated with disease-free survival (adjusted hazard ratio [HR], 0.983; 95% confidence interval [CI], 0.937-1.031; p = 0.475 and adjusted HR, 1.001; 95% CI, 0.995-1.006; p = 0.751, respectively). The delta SMI and VAT were also not significantly associated with disease-free survival (adjusted HR, 0.894; 95% CI, 0.766-1.043; p = 0.155 and adjusted HR, 1.001; 95% CI, 0.989-1.014; p = 0.848, respectively). Conclusion: Our study revealed that baseline and early temporal changes in SMI and VAT were not independent prognostic factors regarding disease-free survival in Asian patients undergoing surgery for breast cancer.

• Korean Journal of Radiology
• /
• 제23권11호
• /
• pp.1078-1088
• /
• 2022

Objective: To develop and validate a model using radiomics features from apparent diffusion coefficient (ADC) map to diagnose local tumor recurrence in head and neck squamous cell carcinoma (HNSCC). Materials and Methods: This retrospective study included 285 patients (mean age ± standard deviation, 62 ± 12 years; 220 male, 77.2%), including 215 for training (n = 161) and internal validation (n = 54) and 70 others for external validation, with newly developed contrast-enhancing lesions at the primary cancer site on the surveillance MRI following definitive treatment of HNSCC between January 2014 and October 2019. Of the 215 and 70 patients, 127 and 34, respectively, had local tumor recurrence. Radiomics models using radiomics scores were created separately for T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and ADC maps using non-zero coefficients from the least absolute shrinkage and selection operator in the training set. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of each radiomics score and known clinical parameter (age, sex, and clinical stage) in the internal and external validation sets. Results: Five radiomics features from T2WI, six from CE-T1WI, and nine from ADC maps were selected and used to develop the respective radiomics models. The area under ROC curve (AUROC) of ADC radiomics score was 0.76 (95% confidence interval [CI], 0.62-0.89) and 0.77 (95% CI, 0.65-0.88) in the internal and external validation sets, respectively. These were significantly higher than the AUROC values of T2WI (0.53 [95% CI, 0.40-0.67], p = 0.006), CE-T1WI (0.53 [95% CI, 0.40-0.67], p = 0.012), and clinical parameters (0.53 [95% CI, 0.39-0.67], p = 0.021) in the external validation set. Conclusion: The radiomics model using ADC maps exhibited higher diagnostic performance than those of the radiomics models using T2WI or CE-T1WI and clinical parameters in the diagnosis of local tumor recurrence in HNSCC following definitive treatment.

• Korean Journal of Radiology
• /
• 제22권3호
• /
• pp.425-434
• /
• 2021

Objective: To investigate the potential value of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT in predicting the survival of patients with primary tracheal malignant tumors. Materials and Methods: An analysis of FDG PET/CT findings in 37 primary tracheal malignant tumor patients with a median follow-up period of 43.2 months (range, 10.8-143.2 months) was performed. Cox proportional hazards regression analyses were used to assess the associations between quantitative ¹⁸F-FDG PET/CT parameters, other clinic-pathological factors, and overall survival (OS). A risk prognosis model was established according to the independent prognostic factors identified on multivariate analysis. A survival curve determined by the Kaplan-Meier method was used to assess whether the prognosis prediction model could effectively stratify patients with different risks factors. Results: The median survival time of the 37 patients with tracheal tumors was 38.0 months, with a 95% confidence interval of 10.8 to 65.2 months. The 3-year, 5-year and 10-year survival rate were 54.1%, 43.2%, and 16.2%, respectively. The metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value, age, pathological type, extension categories, and lymph node stage were included in multivariate analyses. Multivariate analysis showed MTV (p = 0.011), TLG (p = 0.020), pathological type (p = 0.037), and extension categories (p = 0.038) were independent prognostic factors for OS. Additionally, assessment of the survival curve using the Kaplan-Meier method showed that our prognosis prediction model can effectively stratify patients with different risks factors (p < 0.001). Conclusion: This study shows that ¹⁸F-FDG PET/CT can predict the survival of patients with primary tracheal malignant tumors. Patients with an MTV > 5.19, a TLG > 16.94 on PET/CT scans, squamous cell carcinoma, and non-E1 were more likely to have a reduced OS.

• Korean Journal of Radiology
• /
• 제22권2호
• /
• pp.159-167
• /
• 2021

Objective: The aim of this study was to compare the survival rates of Korean females aged 40 to 49 years with breast cancer detected by supplemental screening ultrasound (US) or screening mammography alone. Materials and Methods: This single-institution retrospective study included 240 patients with breast cancer (mean age, 45.1 ± 2.8 years) detected by US or mammography who had undergone breast surgery between 2003 and 2008. Medical records were reviewed for clinicopathologic characteristics and detection methods. Disease-free survival (DFS) and overall survival (OS) were compared between patients with breast cancer in the US and mammography groups using the log-rank test. Multivariable cox regression analysis was used to identify independent variables associated with DFS and OS. Results: Among the 240 cases of breast cancer, 43 were detected by supplemental screening US and 197 by screening mammography (mean follow-up: 7.4 years, 93.3% with dense breasts). There were 19 recurrences and 16 deaths, all occurring in the mammography group. While the US group did not differ from the mammography group in tumor stage, the patients in this group were more likely to undergo breast-conserving surgery and radiation therapy than the mammography group. The US group also showed better DFS (p = 0.016); however, OS did not differ between the two groups (p = 0.058). In the multivariable analysis, the US group showed a lower risk of recurrence (hazard ratio, 0.097; 95% confidence interval, 0.001-0.705) compared to the mammography group. Conclusion: Our study found that Korean females aged 40-49 years with US-detected breast cancer showed better DFS than those with mammography-detected breast cancer. However, there were no statistically significant differences in OS.

• 한국중재학회지:중재연구
• /
• 제15권2호
• /
• pp.3-35
• /
• 2005

The meaning of Online ADR lies in the prompt and economical resolution of disputes by applying the information/communication element (Internet) to existing ADR. However, if the promptness and economical efficiency are overemphasized, the fairness and appropriateness of dispute resolution may be compromised and consequently Online ADR will be belittled and criticized as second-class trials. In addition, as communication is mostly made using texts in Online ADR it is difficult to investigate cases and to create atmosphere and induce dynamic feelings, which are possible in the process of dispute resolution through face-to-face contact. Despite such difficulties, Online ADR is expanding its area not only in online but also in offline due to its advantages such as promptness, low expenses and improved resolution methods, and is expected to develop rapidly as the electronic government decided to adopt it in the future. Accordingly, the following points must be focused on for the continuous First, in the legal and institutional aspects for the development of Online ADR, it is necessary to establish a framework law on ADR. A framework law on ADR comprehending existing mediation and arbitration should be established and it must include contents of Online ADR, which utilizes electronic communication means. However, it is too early to establish a separate law for Online ADR because Online ADR must develop based on the theoretical system of ADR. Second, although Online ADR is expanding rapidly, it may take time to be settled as a tool of dispute resolution. As discussed earlier, additionally, if the amount of money in dispute is large or the dispute is complicated, Online ADR may have a negative effect on the resolution of the dispute. Thus, it is necessary to apply Online ADR to trifle cases or domestic cases in the early stage, accumulating experiences and correcting errors. Moreover, in order to settle numerous disputes effectively, Online ADR cases should be analyzed systematically and cases should be classified by type so that similar disputes may be settled automatically. What is more, these requirements should reflected in developing Online ADR system. Third, the application of Online ADR is being expanded to consumer disputes, domain name disputes, commercial disputes, legal disputes, etc., millions of cases are settled through Online ADR, and 115 Online ADR sites are in operation throughout the world. Thus Online ADR requires not temporary but continuous attention, and mediators and arbitrators participating in Online ADR should be more intensively educated on negotiation and information technologies. In particular, government-led research projects should be promoted to establish Online ADR model and these projects should be supported by comprehensive researches on mediation, arbitration and Online ADR. Fourth, what is most important in the continuous development and expansion of Online ADR is to secure confidence in Online ADR and advertise Online ADR to users. For this, incentives and rewards should be given to specialists such as lawyers when they participate in Online ADR as mediators and arbitrators in order to improve their expertise. What is more, from the early stage, the government and public institutions should have initiative in promoting Online ADR so that parties involved in disputes recognize the substantial contribution of Online ADR to dispute resolution. Lastly, dispute resolution through Online ADR is performed by organizations such as Korea Institute for Electronic Commerce and Korea Consumer Protection Board and partially by Korean Commercial Arbitration Board. Online ADR is expected to expand its area to commercial disputes in offline in the future. In response to this, Korean Commercial Arbitration Board, which is an organization for commercial dispute resolution, needs to be restructured.

• 인간행동과 음악연구
• /
• 제4권2호
• /
• pp.1-17
• /
• 2007

청소년기는 성장과 발달의 과도기적 단계로 모든 영역에서의 발달과 새로운 역할 수행, 학업수준의 향상으로 인한 부담감 등 커다란 변화를 겪게 된다. 이 시기의 청소년은 발달 과제를 해내지 못하거나 변화로 인한 좌절이나 갈등을 반복하는 경우 스트레스와 우울 같은 심리적 어려움을 토로하게 되고, 성숙한 대처를 못하거나 극복하지 못하는 경우 우울이나 불안 같은 정신장애를 얻기도 한다. 오늘날 현대 사회의 청소년을 위한 실질적인 정신건강이나 정신장애에 대한 대응과 예방은 미비하며, 이에 청소년을 위한 상담이나 심리치료 프로그램의 개발이 절실히 요구되고 있다. 그러므로 본 연구에서는 우울 성향을 가진 여중생에게 블루스 음악형식을 활용한 자기효능감 증진 연주활동을 시행하여 참여자들의 우울과 자기효능감에 대해 미치는 영향과 대상자들이 연주를 통해 어떠한 경험을 했는지에 대해 살펴보고자 하였다. 연구 참여자는 서울시 소재 D중학교 1학년에 재학 중인 여자 중학생 3명으로 연구자가 70여명의 학생들에게 아동우울척도(CDI)와 자기효능감척도 검사를 실시하여 선별한 여학생들이다. 실시된 10회기의 연주활동은 3단계로 나누어지는데, 1단계에서는 자기소개와 라포형성, 블루스 음악소개와 블루스 음악형식 연주를 통한 활동에 대한 흥미 유발을 목표로 진행하였다. 2단계에서는 블루스 음악에서 자주 볼 수 있는 특징적인 부분인 부점, 셋잇단음표, 엇박자를 활용한 블루스 음악형식을 연주해 익히고, 5회기 동안 각 회기에서 수행하는 음악과제의 난이도를 달리하여 음악연주과제(즉흥연주 포함)를 수행하도록 하였다. 3단계에서는 전 단계에서 배워 연주했던 곡들을 정리하고 각 대상자들이 곡을 선택하거나 새로운 곡을 창작하여 연습한 뒤 음악연주 발표시간을 가짐으로써 완수경험의 극대화로 음악연주에 대한 경험을 확장하는 시간으로 활용하고자 하였다. 연구결과는 첫째, 연주활동에 참여한 참가자들의 우울 점수는 유의미한 차이를 보이진 않았으나 우울과 자기효능감이 부적상관관계가 있음을 볼 수 있었다. 둘째, 연주활동에 참여한 참가자들의 자기효능감에 미친 영향으로는 자기효능감의 세 가지 하위영역 중 과제난이도선호에서 유의미한 차이를 보여주었다. 셋째, 연주활동에 참가자들의 음악연주에 대한 자기효능감의 세 가지 하위영역 중 과제난이도 선호에서 유의미한 차이를 보여주었다. 넷째, 사후 인터뷰 질문지의 내용과 대상자들의 각 회기 세션 내용을 질적으로 서술하고 분석해 본 결과 대상자들은 블루스 음악형식 연주활동을 통해 과제난이도를 달리하여 연주활동을 했을 때, 자신감을 경험하고 긍정적인 정서를 경험했으며 대상자들에게 의미 있는 경험이었다는 것을 알 수 있었다. 마지막으로 본 연주활동의 효과와 대상자들의 음악경험의 결과와 의미를 볼 때에 블루스 음악형식을 활용한 연주활동이 치료적인 중재 도구로서의 가능성이 있음을 시사한다.

• 한국가정과교육학회지
• /
• 제23권1호
• /
• pp.113-141
• /
• 2011

본 연구의 목적은 중학교 기술 가정 교과의 식품표시와 관련된 수업을 ARCS 동기유발전략을 적용하여 개발한 후 이 수업이 학습동기와 식품표시에 대한 인식과 활용에 효과를 주는지 검증하는데 있다. 본 연구의 목적을 달성하기 위해 ARCS 동기유발 전략을 적용한 식품표시 관련 가정과 수업의 교수 학습 과정안을 총 4차시 개발하였고, 사전-사후 실험설계를 사용하여, 실험집단 4학급은 ARCS 동기유발전략을 적용한 수업을, 비교집단 3학급은 강의식 수업을 적용하여 실험집단과 비교집단의 사전 점수와 사후 점수를 비교하였다. 불성실하게 응답한 7부를 제외한 203부를 대상으로 SPSS Win 12.0을 이용하여 공변량분석(ANCOVA)을 실시하였다. 본 연구의 결과는 다음과 같다. 첫째, ARCS 동기유발전략을 적용한 식품표시 관련 가정과 수업의 교수 학습 과정안과 학습자료, 교사용 참고자료를 4개의 학습주제(영양성분표시, 식품첨가물, 유전자조작과 방사선조사식품, 식품품질인증표시)별로 개발하였다. 둘째, 학습동기에 대한 실험에서 사전 학습동기를 통제한 공변량 분석을 실시한 결과, ARCS 동기유발수업을 받은 실험집단과 강의식 수업을 받은 비교집단의 학습동기와 동기유발요소(주의집중, 관련성, 자신감, 만족감) 모두에서 유의미한 차이를 보였다. 셋째, 사전 식품표시에 대한 인식을 통제한 공변량 분석을 실시한 결과, 사후 식품표시에 대한 인식 검사에서 식품표시에 대한 인식이 수업방법에 따라 실험집단과 비교집단 간에 유의한 차이를 보였다. 그리고 식품표시에 대한 인식 하위영역인 식품표시사항 이해도와 식품표시 실생활 도움 및 교육필요도에서도 모두 유의한 차이를 보였다. 넷째, 사전 식품표시 활용도를 통제한 공변량 분석을 실시한 결과, 식품표시 활용도에 대한 사후 식품표시 활용도는 수업방법에 따라 실험집단과 비교집단간에 유의한 차이를 보였다. 그리고 식품표시 활용도 하위영역인 식품표시사항 활용도와 식품선택시 활용도 모두에서도 유의한 차이를 보였다.