Conditional GAN을 이용한 SAR 표적영상의 해상도 변환

박지훈,서승모,최여름,유지희,Park, Ji-Hoon,Seo, Seung-Mo,Choi, Yeo-Reum,Yoo, Ji Hee 한국군사과학기술학회 2021 한국군사과학기술학회지 Vol.24 No.1

For successful automatic target recognition(ATR) with synthetic aperture radar(SAR) imagery, SAR target images of the database should have the identical or highly similar resolution with those collected from SAR sensors. However, it is time-consuming or infeasible to construct the multiple databases with different resolutions depending on the operating SAR system. In this paper, an approach for resolution conversion of SAR target images is proposed based on conditional generative adversarial network(cGAN). First, a number of pairs consisting of SAR target images with two different resolutions are obtained via SAR simulation and then used to train the cGAN model. Finally, the model generates the SAR target image whose resolution is converted from the original one. The similarity analysis is performed to validate reliability of the generated images. The cGAN model is further applied to measured MSTAR SAR target images in order to estimate its potential for real application.

농촌유역 물순환 해석을 위한 웹기반 자료 전처리 및 모형 연계 기법 개발

박지훈,강문성,송정헌,전상민,김계웅,류정훈,Park, Jihoon,Kang, Moon Seong,Song, Jung-Hun,Jun, Sang Min,Kim, Kyeung,Ryu, Jeong Hoon 한국농공학회 2015 한국농공학회논문집 Vol.57 No.5

Establishment of appropriate data in certain formats is essential for agricultural water cycle analysis, which involves complex interactions and uncertainties such as climate change, social & economic change, and watershed environmental change. The main objective of this study was to develop web-based Data processing and Model linkage Techniques for Agricultural Water-Resource analysis (AWR-DMT). The developed techniques consisted of database development, data processing technique, and model linkage technique. The watershed of this study was the upper Cheongmi stream and Geunsam-Ri. The database was constructed using MS SQL with data code, watershed characteristics, reservoir information, weather station information, meteorological data, processed data, hydrological data, and paddy field information. The AWR-DMT was developed using Python. Processing technique generated probable rainfall data using non-stationary frequency analysis and evapotranspiration data. Model linkage technique built input data for agricultural watershed models, such as the TANK and Agricultural Watershed Supply (AWS). This study might be considered to contribute to the development of intelligent watercycle analysis by developing data processing and model linkage techniques for agricultural water-resource analysis.

차원축소 없는 채널집중 네트워크를 이용한 SAR 변형표적 식별

박지훈,최여름,채대영,임호,Park, Ji-Hoon,Choi, Yeo-Reum,Chae, Dae-Young,Lim, Ho 한국군사과학기술학회 2022 한국군사과학기술학회지 Vol.25 No.3

In implementing a robust automatic target recognition(ATR) system with synthetic aperture radar(SAR) imagery, one of the most important issues is accurate classification of target variants, which are the same targets with different serial numbers, configurations and versions, etc. In this paper, a deep learning network with channel attention modules is proposed to cope with the recognition problem for target variants based on the previous research findings that the channel attention mechanism selectively emphasizes the useful features for target recognition. Different from other existing attention methods, this paper employs the channel attention modules without dimensionality reduction along the channel direction from which direct correspondence between feature map channels can be preserved and the features valuable for recognizing SAR target variants can be effectively derived. Experiments with the public benchmark dataset demonstrate that the proposed scheme is superior to the network with other existing channel attention modules.

가상물리시스템 개념을 이용한 임베디드 제어 네트워크 시스템 설계에 관한 연구

박지훈,이석,이경창,Park, Jee-Hun,Lee, Suk,Lee, Kyung-Chang 대한임베디드공학회 2012 대한임베디드공학회논문지 Vol.7 No.5

Recent advances in electronics have enabled various conventional products to incorporate with numerous powerful microcontroller. Generally, an embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. The growing performance and reliability of hardware components and the possibilities brought by various design method enabled implementing complex functions that improve the comport of the system's occupant as well as their safety. A cyber physical system (CPS) is a system featuring a tight combination of, and coordination between, the system's computational and physical elements. The concept of cyber physical system, including physical elements, cyber elements, and shared networks, has been introduced due to two general reasons: design flexibility and reliability. This paper presents a cyber physical system where system components are connected to a shared network, and control functions are divided into small tasks that are distributed over a number of embedded controllers with limited computing capacity. In order to demonstrate the effectiveness of cyber physical system, an unmanned forklift with autonomous obstacle avoidance ability is implemented and its performance is experimentally evaluated.

지형학적 관점에서 본 고대인의 생활터전 유형 및 시굴 추천지점 -충남 아산 '온주지구 도시개발 사업부지'를 사례로-

박지훈,Park, Ji-Hoon 한국제4기학회 2011 제사기학회지 Vol.25 No.2

본 연구목적은 지형학적 관점에서 유구가 매몰되어 있을 가능성이 높은 구릉의 특정한 구역을 추정하여 이를 바탕으로 시굴 추천구역을 제시하고자 하는 것이다. 즉, 필자는 충남 아산 '온주지구 도시개발 사업부지'(이하 조사지역)를 대상으로 당시 거주했던 고대인의 생활터전 유형을 파악하고 그리고 조사지역에 분포하는 구릉의 미지형 특성을 고려하여 유구가 매몰되어 있을 가능성이 높은 구역을 추천하고자 한다. 분석결과는 다음과 같다. (1) 조사지역 일대에서 거주했을 고대인의 생활터전 유형은 크게 Type-I의 '저구릉+저습지' 그리고 Type-II의 '대소(大小)의 선상지(또는 하안단구)+저습지' 인 것으로 밝혀졌다. (2) 조사지역에서 유구 분포 가능성이 높은 구역 즉, 시굴 추천구역은 '구릉의 미지형 단위'를 기준으로 살펴보면, 정부사면과 정부평탄면이다. 정부사면과 정부평탄면이 조사지역에서 차지하는 개별 면적 비율은 각각 12.9%와 10.2%로서 면적 순위로는 각각 3위와 6위에 해당된다. 그리고 조사지역의 곡저평야(또는 곡저면)에서 시굴 추천구역은 소규모 선상지의 선단 혹은 매몰선단 부근이다. The purpose of this study is to assume the particular area of hills where it is highly possible for historical site to be buried in the viewpoint of geomorphology and based on this to suggest excavation-recommended area. Namely, this writer is to understand the dwelling site type of ancient people who had resided there at that time for the object of 'Ohnju region urban development business site' (referred as investigation area hereinafter) and considering the characteristics of micro-landform of hills which are distributed in investigation area and is to recommend the area where it is highly possible for historical site to be buried. The result of analysis is like the following. (1) Dwelling site types of ancient people who might have resided in the whole area of investigation region are discovered to be largely 'low hills+wetland' of Type-I and 'alluvial fan(or river terrace+wetland' of Type-II. (2) In investigation area if the area which has high possibility of distribution of historical site namely, excavation-recommended area is looked as based on micro-landform unit of hills, they are Crest slope and Crest flat. Individual area ratios which Crest slope and Crest flat occupies in investigation area are 12.9% and 10.2% respectively and the rankings are 3 and 6 each. And excavation-recommended areas in valley plain(or bottomland) of investigation area are in the vicinity of 'distal end' or 'buried distal end'of small scale alluvial fan.

합성곱 신경망의 Channel Attention 모듈 및 제한적인 각도 다양성 조건에서의 SAR 표적영상 식별로의 적용

박지훈,서승모,유지희,Park, Ji-Hoon,Seo, Seung-Mo,Yoo, Ji Hee 한국군사과학기술학회 2021 한국군사과학기술학회지 Vol.24 No.2

In the field of automatic target recognition(ATR) with synthetic aperture radar(SAR) imagery, it is usually impractical to obtain SAR target images covering a full range of aspect views. When the database consists of SAR target images with limited angular diversity, it can lead to performance degradation of the SAR-ATR system. To address this problem, this paper proposes a deep learning-based method where channel attention modules(CAMs) are inserted to a convolutional neural network(CNN). Motivated by the idea of the squeeze-and-excitation(SE) network, the CAM is considered to help improve recognition performance by selectively emphasizing discriminative features and suppressing ones with less information. After testing various CAM types included in the ResNet18-type base network, the SE CAM and its modified forms are applied to SAR target recognition using MSTAR dataset with different reduction ratios in order to validate recognition performance improvement under the limited angular diversity condition.

후두전적출술후 기관공재발의 위험요소 분석

박지훈,김형진,오병훈,최건,정광윤,최종욱,Park, Ji-Hoon,Kim, Hyung-Jin,Oh, Byung-Hoon,Choi, Geon,Jung, Kwang-Yoon,Choi, Jong-Ouck 대한기관식도과학회 2000 大韓氣管食道科學會誌 Vol.6 No.1

Background : Stomal recurrence that occasionally follows total laryngectomy is associated with very poor prognosis regardless of treatment modality, so it is very important to identify high risk patients to prevent stomal recurrence. Objectives : We attempted to select an optimal management method to prevent stomal recurrence by analyzing risk factors in each patient who was found to have stomal recurrence following total laryngectomy. Materials and Methods : Risk factors in each of eleven patients who had stomal recurrence out of 159 patients who underwent total laryngectomy in the last ten years were analyzed retrospectively. Data were gathered on risk factors such as the presence of subglottic extension, extralaryngeal extension, thyroid gland invasion, lymph node metastasis, timing of tracheotomy, tumor stage, postoperative radiotherapy, and inclusion of the stoma in the radiotherapy field. Results : There were eight cases of subglottic extension, six cases of extralaryngeal invasion, one case of pharyngocutaneous fistula that occurred as a postoperative complication, and one case who was taken completion laryngectomy following conservation surgery. With the exception of one case who was taken tracheotomy prior to total laryngectomy, all tracheotomies were performed intra-operatively after endotracheal intubation. There was no evidence of paratracheal lymph node or prelaryngeal lymph node metastasis on preoperative neck CT scan. There were six cases of T4 tumors, four cases of T3 tumors, and one case of T2 tumor. Salvage surgery was performed following radiotherapy in three cases, and aside from one case who was not taken post-operative radiotherapy, postoperative radiotherapy including the stoma was performed in the remaining seven cases within one month after surgery. Conclusion : Total laryngectomy with wide paratracheal lymph node dissection, thyroidectomy, and tracheotomy should be performed for patients who have high risk factors such as subglottic extension and advanced stage. We believe that tracheotomy should be precede endotracheal intubation. Efforts should be made to prevent stomal recurrence by utilizing postoperative radiotherapy and by minimizing postoperative complications such as infection and fistula.

실크 피브로인 수화 겔의 형성에 미치는 티로시나아제 및 폴리페놀 화합물의 영향

박지훈,정임,박원호,Park, Ji-Hun,Jeong, Lim,Park, Won-Ho 한국섬유공학회 2009 한국섬유공학회지 Vol.46 No.2

The formation of silk fibroin (SF) hydrogel can be adjusted by changing physical conditions such as concentration of SF aqueous solution, temperature, pH and salts. In this study, tyrosinase (Tyr), which is an enzyme catalyzing the oxidation of phenols such as tyrosine, was used to decrease the gelation time of SF aqueous solution under a fixed conditions. Tyr oxidizes a broad range of phenols into very reactive o-quinones, and consequently quinones undergo non-enzymatic reactions with various nucleophiles. So it is expected that the gelation time of SF aqueous solution could be decreased by polyphenol compound such as caffeic acid and chlorogenic acid. The color of SF aqueous solutions containing Tyr was changed into deeper yellow with Tyr concentration, and also the gelation time of SF aqueous solution slightly decreased. However, the effect of Tyr concentration on gelation time of SF aqueous solution was not significant due to the locational hindrance of tyrosyl residues in SF. Absorbance at 550 nm also showed conformational transition (random coil to $\beta$-sheet conformation) of SF structure. When polyphenol compounds were added into SF/Tyr aqueous solution, the gelation time slightly decreased. However, the phase separation occurred when polyphenol compounds more than 5 mM were added. The results obtained in this study indicate that enzyme and additives have a potential to regulate the gelation behavior of SF aqueous solution, to some extent.

외상 후 스트레스 장애 환자에서 발생한 환각 경험의 임상적 의미

박지훈,이중서,이홍석,Park, Ji Hoon,Yi, Jung Seo,Lee, Hong Seock 대한불안의학회 2013 대한불안의학회지 Vol.9 No.2

Objectives : The aim of this study was to investigate clinical meaning of hallucination among patients with posttraumatic stress disorder (PTSD). Methods : PTSD patients with hallucination (n=50) were selected and matched with the PTSD patients without hallucination (n=50) by age and sex. The patients were evaluated in two different aspects, pathologic aspects which can develop after traumatic event, and positive/adaptive aspects which are concerned in positive psychology. In addition to these, temperament and character features between two groups were also evaluated using the Temperament and Character Inventory (TCI). Results : Except for the total score of DES (Dissociative Experience Scale) and the score of re-experience subscale of CAPS (Clinician Administered PTSD Scale), clinical characteristics did not show any significant difference between the two groups. Among the comparison of seven higher dimensions in TCI profiles, only Self-transcendence showed significant difference between the two groups. Conclusion : The two groups did not show significant differences in pathologic aspects except for factors that may contribute to development of hallucination. Furthermore, authors could not find any differences in positive/adaptive aspects.

유리피판 및 자가골 이식을 이용한 복합 관골-상악결손 재건의 치험례

박지훈,장정우,최소영,김진수,권대근,Park, Ji-Hoon,Jang, Jung-Woo,Choi, So-Young,Kim, Chin-Soo,Kwon, Tae-Geon 대한악안면성형재건외과학회 2011 Maxillofacial Plastic Reconstructive Surgery Vol.33 No.1

Maxillary defects are inherently complex because they generally involve more than one midfacial component. In addition, most maxillary defects are composite in nature, and often require bony support, as well as a mucosal lining for reconstruction. Therefore, midfacial bone and soft tissue defects present a unique challenge because they require a complex arrangement of tissues in a relatively limited space. This might be difficult to achieve only with free osteocutaneous flaps. The use of bone grafts allows greater flexibility in a reconstruction but is limited by graft resorption. We report a case of a patient reconstructed with a lateral arm free flap, iliac bone graft, sagital split ramus osteotomy for the reconstruction of a right maxillary defect zygomatico-maxillary defect caused by a zygomatico-maxillary malignant tumor resection.