필기체 한글 문자 인식을 위한 획 추출에 관한 연구

최영규,이상범,Choi, Young-Kyoo,Rhee, Sang-Burm 한국정보처리학회 2002 정보처리학회논문지B Vol.9 No.3

필기체 문자 인식은 온라인 필기체 문자 인식과 오프라인 필기체 문자 인식으로 나누어진다. 온라인 필기체 문자 인식은 타블렛과 같은 펜 기반의 전자식 입력 장치를 이용하여 필기의 순서와 획의 위치와 같은 동적인 필기 정보를 문자의 입력 시 획득할 수 있어 오프라인 필기체 문자 인식에 비해 큰 연구 성과를 이루었다. 그러나 오프라인 필기체 문자 인식은 온라인 필기체 문자 인식에서와 같이 동적인 정보를 입력받을 수 없고, 다양한 필기와 자소의 겹침이 심하며 획 사이의 잡영을 많이 가지고 있어 인식의 전처리 결과에 따라 인식 성능이 크게 달라진다. 본 논문에서는 오프라인 필기체 한글 문자 인식을 위해 문자의 동적인 정보를 포함하는 획을 효과적으로 추출하는 방법을 제안한다. 제안된 방법은 전처리 과정으로 먼저 Watershed 알고리즘을 이용하여 입력된 필기체 문자 영상의 향상 및 이진화를 수행한다. 이진화된 문자부를 변형된 Lu와 Wang의 세선화 알고리즘을 사용하여 세선화를 수행한 후 문자에서의 특징점을 추출하여 세그먼트 화소열을 추출하고, 최대 허용 오차법을 이용하여 벡터화한다. 벡터화의 수행으로 몇 개의 획이 하나의 세그먼트로 묶인 경우, 하나의 세그먼트 화소열은 2 또는 그 이상의 세그먼트 벡터로 분리된다. 추출된 세그먼트 벡터들을 완전한 획으로 재구성하기 위해서 오른손 필기 좌표계 시스템을 이용하여 벡터의 방향적인 성분을 인간의 필기 획의 방향에 알맞게 수정하고, 수정된 세그먼트 벡터의 방향성과 분기 정보를 이용하여 인접한 결합 가능한 세그먼트 벡터를 결합함으로써 문자 인식에 적합한 완전한 획으로 재구성한다. 실험 결과 제안된 방법이 필기체 한글 문자 인식에 적합함을 알 수 있었다. Handwritten character recognition is classified into on-line handwritten character recognition and off-line handwritten character recognition. On-line handwritten character recognition has made a remarkable outcome compared to off-line hacdwritten character recognition. This method can acquire the dynamic written information such as the writing order and the position of a stroke by means of pen-based electronic input device such as a tablet board. On the contrary, Any dynamic information can not be acquired in off-line handwritten character recognition since there are extreme overlapping between consonants and vowels, and heavily noisy images between strokes, which change the recognition performance with the result of the preprocessing. This paper proposes a method that effectively extracts the stroke including dynamic information of characters for off-line Korean handwritten character recognition. First of all, this method makes improvement and binarization of input handwritten character image as preprocessing procedure using watershed algorithm. The next procedure is extraction of skeleton by using the transformed Lu and Wang's thinning: algorithm, and segment pixel array is extracted by abstracting the feature point of the characters. Then, the vectorization is executed with a maximum permission error method. In the case that a few strokes are bound in a segment, a segment pixel array is divided with two or more segment vectors. In order to reconstruct the extracted segment vector with a complete stroke, the directional component of the vector is mortified by using right-hand writing coordinate system. With combination of segment vectors which are adjacent and can be combined, the reconstruction of complete stroke is made out which is suitable for character recognition. As experimentation, it is verified that the proposed method is suitable for handwritten Korean character recognition.

Watershed 변환을 이용한 효율적인 문자 영상 향상 및 영역 분할

최영규,이상범,Choi, Young-Kyoo,Rhee, Sang-Burm 한국정보처리학회 2002 정보처리학회논문지B Vol.9 No.4

오프라인 필기체 문자 인식은 동적인 정보를 가지고 있지 않고, 다양한 필기와 자음과 모음의 겹침이 심하며, 획 사이의 잡영을 많이 가지고 있어 불완전한 전처리를 수행하여야 하는 어려움이 있다. 따라서 오프라인 필기체 문자 인식은 다양한 방법의 전처리 즉 이진화 및 세선화에 대한 연구가 필요하다. 본 논문에서는 오프라인 필기체 한글 문자 인식의 전처리로서 워터쉐드 알고리즘의 수행 시간과 결과 영상의 품질을 고려해 그레이 레벨 문자 영상에서의 문자 영역과 배경 영역의 분할을 위한 효과적인 워터쉐드 알고리즘의 적용 방법과 추출된 워터쉐드 영상을 이진화하는 분할 함수를 제안한다. 또한 수행 시간과 골격선의 품질을 고려한 조건 검사 마스크를 통해서 효과적으로 골격선을 추출하는 세선화 방법을 제안하고 기존의 방법과 본 논문 방법을 수행 시간과 품질로써 성능을 평가한다. 실험 결과 기존의 방법은 평균 2.16초, 본 논문 방법은 평균 1.72초의 수행 시간이 걸렸다. 또한 결과 영상의 품질은 본 논문 방법이 문자 획 사이의 잡영을 효과적으로 처리함을 알 수 있었다. Off-line handwritten character recognition is in difficulty of incomplete preprocessing because it has not dynamic information has various handwriting, extreme overlap of the consonant and vowel and many error image of stroke. Consequently off-line handwritten character recognition needs to study about preprocessing of various methods such as binarization and thinning. This paper considers running time of watershed algorithm and the quality of resulting image as preprocessing for off-line handwritten Korean character recognition. So it proposes application of effective watershed algorithm for segmentation of character region and background region in gray level character image and segmentation function for binarization by extracted watershed image. Besides it proposes thinning methods that effectively extracts skeleton through conditional test mask considering routing time and quality of skeleton, estimates efficiency of existing methods and this paper's methods as running time and quality. Average execution time on the previous method was 2.16 second and on this paper method was 1.72 second. We prove that this paper's method removed noise effectively with overlap stroke as compared with the previous method.

장애 환자의 소아치과 치료 시 전신마취에 대한 통계적 고찰

최영규,이성민,김동옥,Choi, Young-Kyoo,Lee, Sung-Min,Kim, Dong-Ok 대한치과마취과학회 2002 Journal of Dental Anesthesia and Pain Medicine Vol.2 No.2

Background: The management of the behavior of handicapped children when providing required dental care is often a problem, whether in the dental office or in a hospital setting. Because of the high incidence of poor cooperation, many of these patients are scheduled for dental care under general anesthesia with preoperative medical assessment. The purpose of this study was to carry out a clinico-statistical survey on dental treatment for handicapped children under general anesthesia. Methods: After approval from the institutional review board, the medical records of 64 handicapped children between 1997 and 2002 were reviewed to determine the patient profiles, anesthesia management, and complications. The charts of these patients, who underwent dental examination, scaling and prophylaxis, and restoration and extraction of teeth under general anesthesia, were reviewed. Results: The mean age was 12.8 years old, and males (53%) predominated females (47%). Twenty-four patients had mental retardation, twelve had autism, six had cerebral palsy, 4 had behavior disorder, others had heart disease, convulsive disorder, etc. Sixty-two had intravenous thiopental with neuromuscular blocker, 2 had intravenous ketamine induction. Nasotracheal intubation was uneventful in 55 patients, nine had orotracheal intubation because of difficult visualization of the larynx. Twenty-one patients experienced postoperative complications in the recovery room, including epistaxis, nasal obstruction, vomiting, airway obstruction, respiratory depression. Conclusions: General anesthesia is a very effective way of completing the dental treatments for disabled children. We emphasize the need to train anesthesiologists in the care of disabled patients.

Lowe 증후군을 동반한 소아치과 환자의 전신 마취 경험 -증례 보고-

최영규,오재열,김동옥,신옥영,이긍호,Choi, Young-Kyoo,Oh, Jae-Yeol,Kim, Dong-Ok,Shin, Ok-Young,Lee, Keung-Bo 대한치과마취과학회 2002 Journal of Dental Anesthesia and Pain Medicine Vol.2 No.1

The oculo-cerebro-renal syndrome of Lowe (Lowe syndrome) is an X-linked recessive disorder involving the eyes, nervous systems, and kidneys. The clinical manifestation of this syndrome is characterized by congenital cataracts, glaucoma, seizure disorder, psychomotor growth retardation, hypotonia, renal tubular acidosis, aminoaciduria, rickets, and osteoporosis. We report a 5-year old boy underwent general anesthesia for the treatment of multiple dental carries. During intraoperative period, marked metabolic acidosis was noted and such acidosis was partially corrected by hyperventilation. We suggest that patients with Lowe's syndrome should be attention and treated to possible anesthetic hazards such as metabolic acidosis due to renal tubular dysfunction, rise of intraocular pressure in patient with glaucoma, the fragility of the bone structures due to rickets and osteoporosis.

부인과 수술 후 오심 및 구토 예방을 위한 Ramosetron의 적정 용량 연구

최영규 ( Young Kyoo Choi ),김형준 ( Hyoung Jun Kim ),박성욱 ( Sung Wook Park ),김건식 ( Keon Sik Kim ) 대한마취과학회 2008 Korean Journal of Anesthesiology Vol.54 No.5

원저 : 뇌수술환자에서 Mannitol 과 Furosemide 투여에 의한 혈청 전해질의 변화 ( Original Article : Mannitol and Mannitol - Furosemide Induced Changes in Serum Electrolytes in Neurosurgical Patients )

최영규(Young Kyoo Choi),최승옥(Seung Ok Choi),이두익(Doo Ik Lee) 경희대학교 경희의료원 1996 慶熙醫學 Vol.12 No.1

임상연구 : 항히스타민제 전처치 후 Atracurium Besylate 투여 시 혈역학적 변화의 측정

최영규 ( Young Kyoo Choi ),임태완 ( Tae Wan Lim ),김대언 ( Dae Eon Kim ),이동현 ( Dong Hyun Lee ),박성욱 ( Sung Wook Park ),김건식 ( Keon Sik Kim ),강화자 ( Wha Ja Kang ),이두익 ( Doo Ik Lee ) 대한마취과학회 2007 Korean Journal of Anesthesiology Vol.52 No.6

Background: Hemodynamic changes through the histamine-induced release of atracurium are relatively common, but can be particularly dangerous in hemodynamically unstable patients. This study evaluated the effectiveness of a pretreatment with an anti-histamine agent before the administration of atracurium in the prevention of histamine-induced hemodynamic changes. Methods: Forty-eight ASA class I and II patients were assigned to four groups. Groups 1 and 2 were assigned to receive atracurium through a bolus 0.5 mg/kg. Groups 3 and 4 were assigned to receive atracurium through a bolus 1.0 mg/kg. Group 1 and 3 were pretreated with pheniramine (H1-blocker) and ranitidine (H2-blocker) intravenously before the induction of general anesthesia. After induction, Hemosonic(TM) 100 was installed and the following hemodynamic parameters were measured: systemic vascular resistance (SVR), cardiac index (CI), heart rate (HR) and blood pressure (BP) immediately before, 1, 2, 3, 5 and 10 min after the rapid administration of the atracurium bolus before the skin incision. Results: Groups 1 and 3 showed more stable hemodynamics than groups 2 and 4. Group 2 showed more significant changes in the SVR, CI, BP, HR than group 1 (P<0.05). Group 4 showed more significant changes in the SVR, CI, BP, HR than group 3, and some cases were significant hemodynamically (P<0.05). Group 4 showed more significant changes in the SVR, CI, BP, HR than group 2 (P<0.05). Conclusions: Pretreatment with an anti-histamine drug prior to the administration of atracurium can be effective in attenuating the hemodynamic responses. (Korean J Anesthesiol 2007; 52: 642~8)

원저 : 뇌수술환자에서 Mannitol 투여량에 따른 혈청 전해질의 변화 ( Original Article : The Changes in Serum Electrolytes with Doses of Mannitol Administration in Neurosurgical Patients )

최영규(Young Kyoo Choi),김용주(Yong Joo Kim),김건식(Keon Sik Kim),이두익(Doo Ik Lee),권무일(Moo Il Kwon),신광일(Kwang Il Shin) 경희대학교 경희의료원 1995 慶熙醫學 Vol.11 No.2

임상연구 : Nicardipine의 지속적 정주가 기관내삽관시 혈압과 심박수에 미치는 영향

김영순 ( Young Soon Kim ),강화자 ( Wha Ja Kang ),김상영 ( Sang Young Kim ),최영규 ( Young Kyoo Choi ),신옥영 ( Ok Young Shin ) 대한마취과학회 2007 Korean Journal of Anesthesiology Vol.53 No.3

경구기관삽관법과 경비기관삽관법의 심혈관계 영향에 대한 비교

김동옥,최영규,Kim, Dong-Ok,Choi, Young-Kyoo 대한치과마취과학회 2001 Journal of Dental Anesthesia and Pain Medicine Vol.1 No.1

Background: This prospective study was designed to compare the cardiovascular response to endotracheal insertion of either an orotracheal tube or a nasotracheal tube Methods: 120 ASA physical status I and II surgical patients requiring general anesthesia and tracheal intubation were studied and assigned to two groups: orotracheal intubation group (n = 60) and nasotracheal intubation group (n = 60). Patients were premedicated with midazolam 0.05 mg/kg and glycopyrrolate 0.005 mg/kg intramuscularly and anesthesia was induced with thiopental sodium 5 mg/kg and succinylcholine 0.1 mg/kg intravenously. Systolic blood pressure (SBP), diastolic blood pressure (DBP). mean arterial pressure (MAP) and heart rate (HR) were assessed noninvasively before induction of anesthesia and immediately after intubation, 1 min, 2 min, 3 min, and 5 min after intubation. Results: Cardiovascular responses such as SBP, DBP, MAP and HR were similar for both techniques and no significant differences between two groups were observed until 5 min after intubation. Conclusions: In healthy ASA I and II patients with normal blood pressure, induction doses of thiopental sodium 5 mg/kg and succinylcholine 0.1 mg/kg didn't attenuated the cardiovascular response to laryngoscopy and tracheal intubation. Insertion of an endotracheal tube may be the most invasive stimulus during intubation procedures. (JKDSA 2001; 1: 10-15)