To detect the position of the camera from a sequence of un-calibrated images

Jaeseung Yu,Taehoon Kang,Kwanghee Choi,Mingi Kim 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

This paper presents a method of detecting the camera position from an un-calibrated image sequence. In Epipolar geometry, the fundamental matrix provides some geometric information including translation and rotation of the cameras. But the information is inexplicitly encapsulated and does not have the scale factor which raises a problem about the displacement or the direction of the sequential motion of the camera. In this paper, the scale of the direction of each camera movement is synchronized comparing the camera matrix which is from the fundamental matrix of some two images with the others. Furthermore, scale factors are determined using the knowledge of the displacement which is made by the first motion of the camera. And to achieve good results the fundamental matrix is computed by the Levenberg-arquardt algorithm using the Direct Linear Transformation algorithm to find the initial value. Experimental results show that the track of the camera is accurately estimated.

자율주행 자동차의 종횡방향 통합 충돌 회피 경로 생성 알고리즘

유재승(Jaeseung Yu),이기범(Kibeom Lee) 한국자동차공학회 2023 한국자동차공학회 학술대회 및 전시회 Vol.2023 No.11

Statistical Techniques based Computer-aided Diagnosis (CAD) using Texture Feature Analysis: Applied of Cerebral Infarction in Computed Tomography (CT) Images

Jaeseung Lee,Inchul Im,Yunsik Yu,Hyonghu Park,Byungjoon Kwak 대한의생명과학회 2012 Biomedical Science Letters Vol.18 No.4

The brain is the body"s most organized and controlled organ, and it governs various psychological and mental functions. A brain abnormality could greatly affect one"s physical and mental abilities, and consequently one"s social life. Brain disorders can be broadly categorized into three main afflictions: stroke, brain tumor, and dementia. Among these, stroke is a common disease that occurs owing to a disorder in blood flow, and it is accompanied by a sudden loss of consciousness and motor paralysis. The main types of strokes are infarction and hemorrhage. The exact diagnosis and early treatment of an infarction are very important for the patient"s prognosis and for the determination of the treatment direction. In this study, texture features were analyzed in order to develop a prototype auto-diagnostic system for infarction using computer auto-diagnostic software. The analysis results indicate that of the six parameters measured, the average brightness, average contrast, flatness, and uniformity show a high cognition rate whereas the degree of skewness and entropy show a low cognition rate. On the basis of these results, it was suggested that a digital CT image obtained using the computer auto-diagnostic software can be used to provide valuable information for general CT image auto-detection and diagnosis for pre-reading. This system is highly advantageous because it can achieve early diagnosis of the disease and it can be used as supplementary data in image reading. Further, it is expected to enable accurate medical image detection and reduced diagnostic time in final-reading.

사이버 공격 대응을 위한 최신 망분리 공격 동향 연구

유재현(Yu JaeHyun),박장용(Park JangYong),송재승(Song JaeSeung) 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.2

망분리는 네트워크 보안기법의 일종으로써 외부의 공격으로부터 내부의 자료를 보호하기 위해 망을 분리하는 것을 의미한다. 인터넷의 발달로 빈번히 발생하고 있는 해킹 및 악성프로그램과 같은 사이버 공격으로부터 중요 정보를 보호하기 위해 망분리 기술이 사회 곳곳에서 사용되어 지고 있다. 본 논문은 최근 증가하고 있는 망분리 환경에서의 해킹기법인 Air Gap 공격에 대해 다루고 있다. 다양한 기술들이 Air Gap 공격에 접목됨으로 인해 안전한 영역은 사라지고 있다. 본 논문에서는 최근까지 이루어진 다양한 Air Gap 공격들에 대해 알아보고, 향후 Air Gap 공격을 막기 위해 필요한 연구에 대해 논한다.

구리박판의 열 산화법을 이용한 산화구리 나노선의 형성

조재승(Jaeseung Jo),조재유(Jae Yu Cho),허재영(Jaeyeong Heo) 한국신재생에너지학회 2017 신재생에너지 Vol.13 No.2

Wrong Siren! A Location Spoofing Attack on Indoor Positioning Systems: The Starbucks Case Study

Cho, Junsung,Yu, Jaegwan,Oh, Sanghak,Ryoo, Jungwoo,Song, JaeSeung,Kim, Hyoungshick IEEE 2017 IEEE communications magazine Vol.55 No.3

<P>The Internet of Things interconnects a mass of billions devices, from smartphones to cars, to provide convenient services to people. This gives immediate access to various data about the objects and the environmental context - leading to smart services and increased efficiency. A number of retail stores have started to adopt IoT enabled services to attract customers. In particular, thanks to indoor proximity technologies, it is possible to introduce location-based smart services to customers, for example, transmitting identifiable signals that represent the locations of stores. In this article, we investigate a potential security risk involved in such technologies: physical signals used as identifiers can be captured and forged easily with today's widely available IoT software for implementing location spoofing attacks. We highlight this security risk by providing a case study: an in-depth security analysis of the recently launched Starbucks service called Siren Order.</P>

Importance of Scaffold Flexibility/Rigidity in the Design and Directed Evolution of Artificial Metallo-β-lactamases

Song, Woon Ju,Yu, Jaeseung,Tezcan, F. Akif American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.46

<P>We describe the design and evolution of catalytic hydrolase activity on a supramolecular protein scaffold, Zn<SUB>4</SUB>:<SUP>C96</SUP>RIDC1<SUB>4</SUB>, which was constructed from cytochrome <I>cb</I><SUB>562</SUB> building blocks via a metal-templating strategy. Previously, we reported that Zn<SUB>4</SUB>:<SUP>C96</SUP>RIDC1<SUB>4</SUB> could be tailored with tripodal (His/His/Glu), unsaturated Zn coordination motifs in its interfaces to generate a variant termed Zn<SUB>8</SUB>:<SUP>A104</SUP>AB3<SUB>4</SUB>, which in turn displayed catalytic activity for the hydrolysis of activated esters and β-lactam antibiotics. Zn<SUB>8</SUB>:<SUP>A104</SUP>AB3<SUB>4</SUB> was subsequently subjected to directed evolution via an in vivo selection strategy, leading to a variant Zn<SUB>8</SUB>:<SUP>A104/G57</SUP>AB3<SUB>4</SUB> which displayed enzyme-like Michaelis–Menten behavior for ampicillin hydrolysis. A criterion for the evolutionary utility or designability of a new protein structure is its ability to accommodate different active sites. With this in mind, we examined whether Zn<SUB>4</SUB>:<SUP>C96</SUP>RIDC1<SUB>4</SUB> could be tailored with alternative Zn coordination sites that could similarly display evolvable catalytic activities. We report here a detailed structural and functional characterization of new variant Zn<SUB>8</SUB>:AB5<SUB>4</SUB>, which houses similar, unsaturated Zn coordination sites to those in Zn<SUB>8</SUB>:<SUP>A104/G57</SUP>AB3<SUB>4</SUB>, but in completely different microenvironments. Zn<SUB>8</SUB>:AB5<SUB>4</SUB> displays Michaelis–Menten behavior for ampicillin hydrolysis without any optimization. Yet, the subsequent directed evolution of Zn<SUB>8</SUB>:AB5<SUB>4</SUB> revealed limited catalytic improvement, which we ascribed to the local protein rigidity surrounding the Zn centers and the lack of evolvable loop structures nearby. The relaxation of local rigidity via the elimination of adjacent disulfide linkages led to a considerable structural transformation with a concomitant improvement in β-lactamase activity. Our findings reaffirm previous observations that the delicate balance between protein flexibility and stability is crucial for enzyme design and evolution.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2017/jacsat.2017.139.issue-46/jacs.7b08981/production/images/medium/ja-2017-08981k_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja7b08981'>ACS Electronic Supporting Info</A></P>

Off-Road Machinery System Engineering ; Criteria for Determining Working Area and Operating Cost for Long-Term Lease of Agricultural Machinery

( Seungyeoub Shin ),( Changho Kang ),( Seokcheol Yu ),( Yuyong Kim ),( Jaeseung Noh ) 한국농업기계학회 2015 바이오시스템공학 Vol.40 No.3

Purpose: This research suggests a method of establishing criteria for working area and operating cost for a long-term lease of agricultural machinery. Methods: Eight crops were selected-three food crops and five open-field vegetables-and agricultural machines used for sowing, transplanting, and cultivation in dry-field farming were analyzed. Results: The break-even acreage for agricultural machinery under a long-term lease was found to differ by agricultural machine, ranging from 1.0 to 5.8 ha. In terms of arable land area, the break-even acreages for harvesting machinery and transplanters were 15.6 to 26.1 ha and 6.1 to 8.6 ha, respectively. The working area lessees should secure was divided into two cases: (1) 2.0 to 11.6 ha when leasing individual agricultural machines (sowing and transplanting) for a long-term period, and (2) more than 10 ha when farmers who cultivate beans, potatoes, garlic, onions, and so on lease sowing and transplanting machines as a set. When agricultural machinery was leased for a long term, the operating cost and working time were reduced by 27.6 to 74.4% and 2.5 to 21.6%, respectively, indicating considerable effect. Conclusions: A long-term lease project needs to be promoted to overcome the limitation of short-term leases of agricultural machinery. The local government should lead this project and facilitate the mechanization of dry-field farming. The department in charge of agricultural machinery lease projects needs to set the working area to cover the rate and maintenance cost for farmers who lease agricultural machinery for the long term.

Therapeutic Effect of Schwann Cell-Like Cells Differentiated from Human Tonsil-Derived Mesenchymal Stem Cells on Diabetic Neuropathy in db/db Mice

Yum Yoonji,Park Saeyoung,Nam Yu Hwa,Yoon Juhee,Song Hyeryung,Kim Ho Jin,Lim Jaeseung,Jung Sung-Chul 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.5

Background: Diabetic neuropathy (DN) is the most common complication of diabetes, and approximately 50% of patients with this disease suffer from peripheral neuropathy. Nerve fiber loss in DN occurs due to myelin defects and is characterized by symptoms of impaired nerve function. Schwann cells (SCs) are the main support cells of the peripheral nervous system and play important roles in several pathways contributing to the pathogenesis and development of DN. We previously reported that human tonsil-derived mesenchymal stem cells differentiated into SCs (TMSC-SCs), named neuronal regeneration-promoting cells (NRPCs), which cells promoted nerve regeneration in animal models with peripheral nerve injury or hereditary peripheral neuropathy. Methods: In this study, NRPCs were injected into the thigh muscles of BKS-db/db mice, a commonly used type 2 diabetes model, and monitored for 26 weeks. Von Frey test, sensory nerve conduction study, and staining of sural nerve, hind foot pad, dorsal root ganglia (DRG) were performed after NRPCs treatment. Results: Von Frey test results showed that the NRPC treatment group (NRPC group) showed faster responses to less force than the vehicle group. Additionally, remyelination of sural nerve fibers also increased in the NRPC group. After NRPCs treatment, an improvement in response to external stimuli and pain sensation was expected through increased expression of PGP9.5 in the sole and TRPV1 in the DRG. Conclusion: The NRPCs treatment may alleviate DN through the remyelination and the recovery of sensory neurons, could provide a better life for patients suffering from complications of this disease. Background: Diabetic neuropathy (DN) is the most common complication of diabetes, and approximately 50% of patients with this disease suffer from peripheral neuropathy. Nerve fiber loss in DN occurs due to myelin defects and is characterized by symptoms of impaired nerve function. Schwann cells (SCs) are the main support cells of the peripheral nervous system and play important roles in several pathways contributing to the pathogenesis and development of DN. We previously reported that human tonsil-derived mesenchymal stem cells differentiated into SCs (TMSC-SCs), named neuronal regeneration-promoting cells (NRPCs), which cells promoted nerve regeneration in animal models with peripheral nerve injury or hereditary peripheral neuropathy. Methods: In this study, NRPCs were injected into the thigh muscles of BKS-db/db mice, a commonly used type 2 diabetes model, and monitored for 26 weeks. Von Frey test, sensory nerve conduction study, and staining of sural nerve, hind foot pad, dorsal root ganglia (DRG) were performed after NRPCs treatment. Results: Von Frey test results showed that the NRPC treatment group (NRPC group) showed faster responses to less force than the vehicle group. Additionally, remyelination of sural nerve fibers also increased in the NRPC group. After NRPCs treatment, an improvement in response to external stimuli and pain sensation was expected through increased expression of PGP9.5 in the sole and TRPV1 in the DRG. Conclusion: The NRPCs treatment may alleviate DN through the remyelination and the recovery of sensory neurons, could provide a better life for patients suffering from complications of this disease.

Application of the Orally Inserted Guiding Device for the Improved Motion Artifacts of the Cervical Spine MRI

이재흔(Jaeheun Lee),유윤식(Yunsik Yu),이재승(Jaeseung Lee),임인철(Inchul Im) 한국방사선학회 2014 한국방사선학회 논문지 Vol.8 No.6

본 연구는 임상적으로 정형화된 경추부 MR 검사에서 틀니 제거 환자들의 불수의적 구강운동, 침 삼킴 등의 불수의적 구강 운동에 의한 움직임 인공물을 개선하기 위해 구강내 삽입 유도 기구를 이용한 검사방법을 제안하고 인공물을 최소화하여 질환의 경계가 불분명했던 부분을 명확하게 하여 최적의 영상을 만들고자 하였다. 2014년 1월 1일부터 2014년 6월 31일까지 경추부 질환으로 내원한 환자 중 틀니를 착용한 30명을 대상으로 경추 자기공명검사를 시행하였다. 방법으로는 틀니를 제거한 후 바로 누운(supine position)자세로 T₁-TSE-Sagittal, T₂-TSE-Sagittal, T₁-TSE-Axial, T₂-TSE-Axial을 획득하고 환자의 입에 구강내 삽입 유도 기구를 삽입한 후 T₁-and T₂-TSE-Axial을 검사하였다. 결과로는 정량적 분석 SNR은 구강 삽입 유도 기구 사용 전 T₁-TSE-Axial이 22.33±8.59, 사용 후 25.21±7.93, T₂-TSE-Axial은 사용 전 14.49±5.74, 사용 후 16.61±6.72이었다. CNR은 T₁-TSE-Axial이 0.23±0.01, T₂-TSE-Axial이 0.21±0.01로 측정되었다. 정성적 분석으로는 T₁-TSE-Axial에서 구강내 삽입 유도기구 사용 전 3.49±0.11, 사용 후 3.95±0.14로 나타났으며 T₂-TSE-Axial에서는 구강내 삽입 유도기구 사용 전 3.25±0.18, 삽입 후 3.68±0.09로 나타났다. 결론적으로 구강내 삽입 유도 기구의 사용으로 움직임 인공물이 해소되어 영상의 대조도와 분해능이 향상되었고 영상 판독에 있어 질환의 식별능력이 우수하여 영상의 질이 향상됨을 알 수 있었다. This study aims to suggest and test methods using an orally inserted guiding device in order to improve a motion artifact by involuntary oral motor such as removing one's dentures and swallowing saliva clinically structured cervical spine scan and to make the optimal image by minimizing motion artifact. A cervical spine test was conducted with 30 patients who wore dentures among those who had a cervical spinal disease from January 1, 2014 through June 30, 2014. As for testing methods, after removing denture, T₁-TSE-Sagittal, T₂-TSE-Sagittal, T₁-TSE-Axial and T₂-TSE-Axial were obtained in a normal position and a supine position; the orally inserted guiding device was inserted in patients' mouth; and then T₁-TSE-Axial and T₂-TSE-Axial were retested. As a result, in SNR, T₁-TSE-Axial before inserting an orally inserted guiding device was 22.33±8.59; T₁-TSE-Axial after inserting the orally inserted guiding device was 25.21±7.93; T₂-TSE-Axial before inserting the orally inserted guiding device was 14.49±5.74; and T₂-TSE-Axial after inserting the orally inserted guiding device was 16.61±6.72. In CNR, T₁-TSE-Axial was measured at 0.23±0.01 while T₂-TSE-Axial at 0.21±0.01. As a result of the qualitative analysis, T₁-TSE-Axial before inserting the orally inserted guiding device was 3.49±0.11; T₁-TSE-Axial after inserting the orally inserted guiding device was 3.95±0.14; T₂-TSE-Axial before inserting the orally inserted guiding device was 3.25±0.18; and T₂-TSE-Axial after inserting the orally inserted guiding device was 3.68±0.09. As a result of using an orally inserted guiding device, the resolution and contrast of the images improved as the patients' involuntary artifact decreased because of removing dentures and swallowing saliva, and it was found that the interpretation of the images and identification of the diseases improved.