화성 지형상대항법을 위한 하강 데이터셋 생성과 랜드마크 추출 방법

김재인,Kim, Jae-In 대한원격탐사학회 2022 大韓遠隔探査學會誌 Vol.38 No.6

The Entry-Descent-Landing process of a lander involves many environmental and technical challenges. To solve these problems, recently, terrestrial relative navigation (TRN) technology has been essential for landers. TRN is a technology for estimating the position and attitude of a lander by comparing Inertial Measurement Unit (IMU) data and image data collected from a descending lander with pre-built reference data. In this paper, we present a method for generating descent dataset and extracting landmarks, which are key elements for developing TRN technologies to be used on Mars. The proposed method generates IMU data of a descending lander using a simulated Mars landing trajectory and generates descent images from high-resolution ortho-map and digital elevation map through a ray tracing technique. Landmark extraction is performed by an area-based extraction method due to the low-textured surfaces on Mars. In addition, search area reduction is carried out to improve matching accuracy and speed. The performance evaluation result for the descent dataset generation method showed that the proposed method can generate images that satisfy the imaging geometry. The performance evaluation result for the landmark extraction method showed that the proposed method ensures several meters of positioning accuracy while ensuring processing speed as fast as the feature-based methods.

영상 내 자연표적을 이용한 GRD 측정기법 개발

김재인,정재훈,김태정,Kim, Jae-In,Jeong, Jae-Hoon,Kim, Tae-Jung 대한원격탐사학회 2010 大韓遠隔探査學會誌 Vol.26 No.5

본 논문에서는 영상의 품질 지표인 GRD(Ground Resolved Distance) 측정에 있어서 인공표적만을 이용하던 기존의 측정방식과는 다르게 지표상에 분포하고 있는 자연표적만을 이용하여 신뢰성 있는 GRD 산출이 가능하도록 새로운 방식의 GRD 측정가법을 고안하였다. 자연표적에서 활용 가능한 Edge Profile 추출기법을 개발하여 추출 정확도 및 안정성을 분석하였으며 그 결과, 자연표적을 이용할 경우 본 논문의 추출방식이 가장 적합한 방식임을 확인 할 수 있었다. 이를 적용한 GRD 측정기법의 정확도와 자연 표적에서의 활용 가능성을 평가하기 위해 육안분석결과를 보유하고 있는 인공표적영상과 인공표적이 된 인공위성영상을 이용하여 GRD 측정 실험을 수행하였다. 인공표적영상에서의 GRD 측정결과는 육안분석 결과와 매우 유사하여 높은 정확도를 보여주었으며 인공위성영상에서의 GRD 측정결과, 자연표적과 인공표적에서의 GRD 측정값이 유사하게 나타났다. 이는 제안한 GRD 측정기법을 이용하여 자연표적만으로도 신뢰성 있는 GRD 측정이 가능함을 보여준다. This paper reports a reliable GRD (Ground Resolved Distance) measurement method of using natural targets instead of the method using artificial targets. For this, we developed an edge profile extraction technique suitable for natural targets. We demonstrated the accuracy and stability of this technique firstly by comparing GRD values generated by this technique visually inspected GRD values for artificial targets taken in laboratory environments. We then demonstrated the feasibility of GRD estimation from natural targets by comparing GRD values from natural targets to those from artificial targets using satellite images containing both artificial and natural targets. The GRDs measured from the proposed method were similar to the values from visual inspection and the GRDs measured from the natural targets were similar to the values from artificial targets. These results support our proposed method is able to measure reliable GRD from natural targets.

가로손가락손바닥활을 이용한 다발성 벗겨짐 손상 손가락 재접합술 - 증례보고 -

김재인,최환준,김준혁,탁민성,김용배,Kim, Jae-In,Choi, Hwan-Jun,Kim, Jun-Hyuk,Tark, Min-Seong,Kim, Yong-Bae 대한미세수술학회 2009 Archives of reconstructive microsurgery Vol.18 No.2

Purpose: Avulsion injuries of digits have been presented for a long time as complex management problems. Despite of microsurgical advances, it is difficult to achieve good functional results and their management remains somewhat controversial. However, in a finger there are three transverse digital palmar arches. The middle and distal transverse digital palmar arches are consistently large(almost 1 mm) and may be used for arterial vessel repairs either proximally or distally, depending on the length and direction needed. 39-year-old man presented with avulsion amputation of the ulnar three digits, was operated using only arterial anastomosis with rerouting the transverse digital palmar arches. Methods: Replantation was performed using the artery-only technique. Because the digital arteries had been damaged, we did that the transverse digital palmar arches were transposed in an inverted Y to I configuration and were lengthened with rerouting them for the purpose of direct anastomosis of the digital artery. Venous drainage was provided by an external bleeding method with partial nail excision and external heparin irrigation. Results: The authors conclude that complete avulsion amputations with only soft tissue at the distal to insertion of the flexor digitorum superficialis tendon were salvageable with acceptable functional results. All three fingers survived. Conclusion: With technical advancements, the transverse digital palmar arches play an important role for finger amputation. Three digital palmar arches give us additional treatment option for the finger amputation. In this case, replantation with only-arterial anastomosis was successful and we obtained good aesthetic and functional outcome.

U-Health에서 이벤트 상태 변화를 고려한 시간 마이닝 기법 개발

김재인,김대인,황부현,Kim, Jae-In,Kim, Dae-In,Hwang, Bu-Hyun 한국정보처리학회 2011 정보처리학회논문지D Vol.18 No.4

U-Health는 다양한 종류의 센서로 환자 정보를 수집하며, 스트림 데이터는 시작 시점과 종료 시점을 갖는 인터벌 이벤트로 요약 가능하다. 그러나 대부분의 시간 데이터 마이닝 기법들은 이벤트 발생 시점만을 고려하며 스트림 데이터의 상태 변화는 간과하는 문제가 있다. 이 논문은 U-Health에서 이벤트 상태 변화를 고려한 시간 마이닝 기법을 제안한다. 제안 방법은 U-Health에서 관심이 있는 이벤트만을 센서에서 서버로 전송함으로써 환경의 제약 사항들을 극복하고 스트림 데이터에 대한 네 가지 이벤트 상태를 정의하여 상태 변화를 고려한 시간 마이닝을 수행한다. 최종적으로, 제안 방법은 이벤트들 사이에 존재하는 인과 관계를 시간 관계 시퀀스로 기술하여 탐사 규칙의 모호함을 제거한다. U-Health collects patient information with various kinds of sensor. Stream data can be summarized as an interval event which has aninterval between start-time-point and end-time-point. Most of temporal mining techniques consider only the event occurrence-time-point and ignore stream data change of state. In this paper, we propose the temporal mining technique considering the event change of state in U-Health. Our method overcomes the restrictions of the environment by sending a significant event in U-Health from sensors to a server. We define four event states of stream data and perform the temporal data mining considered the event change of state. Finally, we can remove an ambiguity of discovered rules by describing cause-and-effect relations among events in temporal relation sequences.

Glass Dosimeter를 이용한 환자피폭선량에 관한 분석

김재인,최원근,장성원,오창섭,이관섭,하동윤,Kim, Jae-In,Choi, Won-Keun,Chang, Sung-Won,Oh, Chang-Seop,Lee, Kwan-Sup,Ha, Dong-Yoon 대한디지털의료영상학회 2009 대한디지털의료영상학회논문지 Vol.11 No.1

Far reducing medical radiation exposure and managing patient doses, Entrance surface doses(ESDs) were measured at Diagnostic Radiology Department in ASAN medical center, also we determined and compared with the Diagnostic Reference Level(DRL) of some other countries. ESDs were measured far the most common types of X-ray procedures, such as chest PA, lumbar spine AP, lumbar spine lateral, Pelvis AP, Skull PA. ESDs were measured by Glass dosimeter and Unfors Xi meter. Those were applied collimation center of phantom's entrance skin surface. The results of ESDs were compared Glass dosimeter with Unfors Xi meter. Those were measured within 5% statistical difference. It seemed well agreement at two devices. In most cases ESDs measured far the different types of X ray procedures were found to be lower than the DRL of IAEA, but ESDs on chest PA, lumbar spine AP, lumbar spine lateral, Pelvis AP, Skull PA were proximity ar excesses at DRL of advanced country. Through this study, we need an investigation and improvement at present diagnostic radiology exam system. Also, radiologists make an effort to reduce patient dose and having a technical skill.

남성 유두비대증에서 C-V피판을 이용한 유두축소

김재인,김용배,남승민,박은수,강상규,정성균,Kim, Jae-In,Kim, Yong-Bae,Nam, Seung-Min,Park, Eun-Soo,Kang, Sang-Gyu,Jung, Sung-Gyun 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.2

Purpose: Male nipple hypertrophy is a rare condition but is a social embarrassment for individual. The currently available techniques of nipple reduction already described in the literature for female patients are discussed, but the goal of treatment is different in male patients. In male patient, the diameter as well as vertical height should be reduced simultaneously to achieve better aesthetic results. Our new technique can reduce the diameter of the hypertrophic nipple as well as the vertical height efficiently and simply. Methods: A 19-years-old man with nipple hypertrophy on the right chest presented. The flap is designed based on the site of left nipple, symmetry, the diameter, and the projection desired. The widths of the V flaps determine projection, whereas the diameter of the C flap determines the diameter of the nipple and top of the new nipple. Unnecessary hypertrophic tissues are extirpated and the V flaps are elevated. The nipple base is reduced by purse-string suture technique. The V flaps are wrapped around, and C flap is used as a cap. Results: No complication including nipple necrosis or sensory loss were found during follow-up period. The normal symmetry of the nipple contour was restored. Conclusion: We describe a simple technique for male nipple reduction using a C-V flap with purse-string suture. In our experience, this technique has provided good aesthetic result and patient satisfaction.

치과방사선검사에서 방사선방어용구 사용 전, 후의 유효선량에 대한 평가

김재인,최원근,이소라,이정화,이관섭,Kim, Jae In,Choi, Won Keun,Lee, So La,Lee, Jung Hwa,Lee, Kwan Sub 대한디지털의료영상학회 2012 대한디지털의료영상학회논문지 Vol.14 No.2

The purpose of this study was to measure the absorbed dose and calculate the effective dose for cone beam computed tomography (CBCT) and panorama units and to estimate usefulness of x-ray protective. Rando phantom and glass dosimeters were used for dosimetry. The absorbed doses were measured at 15 organs and 14 remainder from correspond to ICRP 2007 recommendations. The absorbed dose was highest in salivary glands as measured CBCT 2.420mGy, panorama 0.307mGy. Absorbed dose in another organs were high in order of thyroid, brain, skin, esophagus. The effective dose was CBCT 0.100mSv, panorama 0.011mSv and effective dose of panorama was higher than that of CBCT by 10 times. In case of wearing x-ray protective, reducing effective dose of CBCT by 0.066mSv (66%) and panorama by 0.008mSv (72%). Effective dose were reduced by radiological shielding but it needs further optimization studies, where dosimetric data are analyzed in combination with image quality with keep the patients' exposure as low as possible.

발음속도에 따른 한국어의 휴지기 규칙 및 평균음절길이 조절규칙

김재인,김진영,이태원,Kim, Jae-In,Kim, Jin-Young,Lee, Tae-Won 한국음향학회 1995 韓國音響學會誌 Vol.14 No.1

본 논문에서는 18명의 아나운서로부터 녹음된 문장으로부터 분석된 결과를 바탕으로 하여 발음속도에 따른 한국어의 휴지기 규칙과 음절길이 조절규칙에 대하여 논하였다. 휴지기 규칙은 문장과 문장 사이, 절과 절 사이 그리고 말 토막과 말 토막 사이의 휴지지로 나누어 분석하였다. 분석결과로부터 다음과 같은 길이조절규칙을 찾아낼 수 있었다. 낭독체에 있어서 한 문장의 전체길이가 늘어날수록, 즉 발음속도가 늘어날수록, 늘어난 발음길이의 대부분을 문장사이 그리고 절 사이의 휴지기가 차지한다. 그리고 평균음절의 길이는 휴지기에 비교할 때 상대적으로 작게 증가한다. 또한 말 토막사이의 휴지기는 발음을 빠르게 할 때에는 발화되지 않다가 발음속도가 느려짐에 따라서 서서히 발화되기 시작한다. In this paper we extracted control rules of synthetical pauses and syllable durations depending on pronunciation speed in Korean speech from the spoken sentences recorded by 18 professional announcers. Pause rules were divided into three categories : pause between sentences(PBS), pause between clauses(PBC) and pause between intonational phrases(PBI). From the analysis results it is found that comparing the slowly spoken sentence with the fast spoken sentence the duration difference between them is due to the synthetical pause increments, expecially, of PBS and PBC. In addition, it is also found that the increment ratio of the mean syllable duration Is low. On the other hand, PBI was not pronounced in the fast spoken sentences. PBI was pronounced at the pronunciation speed(PS) over some PS.

짧은 구간을 갖는 범위 질의의 효율적인 질의 색인 기법

김재인,송명진,한대영,김대인,황부현,Kim, Jae-In,Song, Myung-Jin,Han, Dae-Young,Kim, Dae-In,Hwang, Bu-Hyun 한국정보처리학회 2009 정보처리학회논문지D Vol.16 No.4

데이터 스트림 환경에서는 지속적으로 입력되는 데이터에 대한 실시간 처리를 수행하기 위하여 범위를 갖는 다수의 질의를 시스템에 미리 등록한다. 등록된 질의를 입력 스트림에 따라 빠르게 검색하기 위해 질의 색인 기법을 사용하는데, 질의 색인은 메인 메모리 기반에서 동작하기 위해 색인 정보의 저장 비용이 낮아야 하고 빠른 질의 탐색을 실시해야 한다. 본 논문에서는 다수의 범위 질의에 대하여 색인 정보의 저장 비용이 낮고 빠른 질의 탐색을 실시하는 질의 색인 기법으로 LVC-based(Limited Virtual Construct-based) 기법을 제안한다. 해시기반으로 동작하는 LVC-based 색인 기법은 입력 스트림의 범위를 가상의 분할 구조로 나눈 LVC를 이용한다. 각 LVC는 식별자가 할당되고 각 LVC에 구간에 해당하는 범위 질의를 저장하며 색인을 실시한다. LVC-based 기법은 입력 스트림의 범위가 길고 범위가 짧은 다수의 질의를 색인할 때 저장비용과 탐색 비용에서 좋은 효율을 보이며 이는 기 제안된 CEI-based 색인 기법과의 비교를 통하여 입증하였다. In stream data processing system, generally the interval queries are in advance registered in the system. When a data is input to the system continuously, for realtime processing, a query indexing method is used to quickly search queries. Thus, a main memory-based query index with a small storage cost and a fast search time is needed for searching queries. In this paper, we propose a LVC-based(Limited Virtual Construct-based) query index method using a hashing to meet the both needs. In LVC-based query index, we divide the range of a stream into limited virtual construct, or LVC. We map each interval query to its corresponding LVC and the query ID is stored on each LVC. We have compared with the CEI-based query indexing method through the simulation experiment. When the range of values of input stream is broad and there are many short interval queries, the LVC-based indexing method have shown the performance enhancement for the storage cost and search time.

GTLS의 ARMA시트템식별에의 적용 및 적응 GTLS 알고리듬에 관한 연구

김재인,김진영,이태원,Kim, Jae-In,Kim, Jin-Young,Rhee, Tae-Won 한국음향학회 1995 韓國音響學會誌 Vol.14 No.3

일반화된 완전최소자승법 (generalized total least squares method, GTLS)의 ARMA 시스템 식별에의 적용과 GTLS의 적응알고리듬에 대하여 논한다. 일반화된 완전최소자승법은 일별과 출력을 알고 있는 시스템식별 (system identification)문제에서, 출력이 잡음에 의하여 오염된 경우, 편이되지 않은 해를 구하기 위하여 사용되는 방법이다. 본 논문에서는 먼저 GTLS를 ARMA 시스템 식별에 적용하기 위한 formulation을 하고, 일반화된 완전최소자승법의 일반 해의 성질과 역행렬 정리 (matrix inverse lemma)를 이용하여 적응 GTLS 방법을 제안한다. 다음 제안된 방법을 통하여 시스템식별에 적용하여 그 성능을 평가한다. 또한 GTLS 알고리듬과 제안한 적응 GTLS 알고리듬의 성능을 수학적으로 해석하고 컴퓨터 시뮬레이션을 통하여 이를 검증한다. This paper presents an sstimation of ARMA coefficients of noisy ARMA system using generalized total least square (GTLS) method. GTLS problem for ARMA system is defined as minimizing the errors between the noisy output vectors and estimated noisy-free output. The GTLS problem is solved in closed form by eigen-problem and the perturbation analysis of GTLS is presented. Also its recursive solution (recursive GTLS) is proposed using the power method and the covariance formula of the projected output error vector into the input vector space. The simulation results show that GTLS ARMA coefficients estimator is an unbiased estimator and that recursive GTLS achieves fast convergence.