딥러닝을 이용한 시퀀스 기반의 여행경로 추천시스템 : 제주도 사례

이희준(Hee Jun Lee),이원석(Won Sok Lee),최인혁(In Hyeok Choi),이충권(Choong Kwon Lee) 한국스마트미디어학회 2020 스마트미디어저널 Vol.9 No.1

딥 러닝의 발전에 따라 추천시스템에서 딥 러닝 기반의 인공신경망을 활용한 연구가 활발히 진행되고 있다. 특히, RNN(Recurrent Neural Network)기반의 추천시스템은 데이터의 순차적 특성을 고려하기 때문에 추천시스템에서 좋은 성과를 보여주고 있다. 본 연구는 RNN기반의 알고리즘인 GRU(Gated Recurrent Unit)와 세션 기반 병렬 미니배치(Session Parallel mini-batch)기법을 활용한 여행경로 추천 시스템을 제안한다. 본 연구는 top1과 bpr(Bayesian personalized ranking) 오차함수의 앙상블을 통해 추천 성과를 향상시켰다. 또한, 데이터 내에 순차적인 특성을 고려한 RNN기반 추천 시스템은 여행경로에 내재된 여행지의 의미가 반영된 추천이 이루어진다는 것을 확인되었다. With the development of deep learning, studies using artificial neural networks based on deep learning in recommendation systems are being actively conducted. Especially, the recommendation system based on RNN (Recurrent Neural Network) shows good performance because it considers the sequential characteristics of data. This study proposes a travel route recommendation system using GRU(Gated Recurrent Unit) and Session-based Parallel Mini-batch which are RNN-based algorithm. This study improved the recommendation performance through an ensemble of top1 and bpr(Bayesian personalized ranking) error functions. In addition, it was confirmed that the RNN-based recommendation system considering the sequential characteristics in the data makes a recommendation reflecting the meaning of the travel destination inherent in the travel route.

자가 슬개건과 동종 슬개건을 이용한 전십자인대의 재건의 비교

변기용,이광진,신현대,이원석,Byun Ki-Yong,Rhee Kwang-Jin,Shin Hyun-Dae,Lee Won-Sok 대한관절경학회 1997 대한관절경학회지 Vol.1 No.1

We have studied the results of reconstruction by freeze-dried patellar allografts or patellar autografts in ACL-deficient patients prospectively. From January 1995 to December 1995, we performed ACL reconstruction using an arthroscopic-assisted technique with patellar autografts in 21 patients and patellar allografts in 13 patients. Minimum followup time was 1 year(average 26 months). All patients were evaluated by using KT-2000 arthrometer and MRI as well as by physical examination. Final results were rated as satisfactory or unsatisfactory by using a modified Feagin knee scoring scale. Good or excellent were considered to have satisfactory results and fair or poor were considered to have unsatisfactory results. As measured by the KT-2000, 19 cases$(90.5\%)$ had a 5-mm or Jess side-to-side differential, a satisfactory results in autograft group, 2 cases of unsatisfactory results had joint instability. In allograft group, 10 cases$(76.9\%)$ had a 5-mm or less side-to-side differential, a satisfactory results, 3 cases of unsatisfactory results had joint instability including postoperative infection(1 case). In conclusion, the results of ACL reconstruction with autografts were better than those with allografts. The problem of allograft reconstruction were rehydration, aseptic control and improper mechanical tensioning. So, we thought that success of allograft reconstruction was depended on careful implant preparation including pretensioning technique.

MOCVD 방식으로 증착한 Cu 박막의 Electronmigration 특성

이정환(Jeung-Hwan Lee),이원석(Won-Sok Lee),이종현(Jong-Hyun Lee),최시영(Sie-Young Choi) 대한전자공학회 1999 대한전자공학회 학술대회 Vol.1999 No.6

동통성 고관절 질환에 대한 관절경적 진단과 치료

황득수(Deuk-Soo Hwang),권순태(Soon-Tae Kwon),이원석(Won-Sok Lee),이광진(Kwang-Jin Rhee) 대한정형외과학회 1998 대한정형외과학회지 Vol.33 No.2

비구 비구순의 파열 -관절경적 진단 및 치료-

황득수 ( Deuk Soo Hwang ),윤승호 ( Seung Ho Yune ),권순태 ( Soon Tae Kwon ),이원석 ( Won Sok Lee ),송재기 ( Jae Gie Song ) 대한고관절학회 1997 Hip and Pelvis Vol.9 No.1

From March 1995 to October 1996, We performed arthroscopy of the hips in symptomatic nine patients under the impression of acetabular labrum tear. Preoperatively, the acetabular labrum tear was diagnosed in thirteen patients with careful physical examinations and MR arthrography and four patients with acetabular dysplasia were excluded from the study. Among nine patients, eight cases were men and seven cases were the fifth and sixth decade. Three cases were associated with trauma history. Superoanterior labrum tear was most common in arthroscopic findings(44.4%). The MR Arthrogram showed 88.9% sensitivity and 77.8% accuracy compared with arthroscopic findings for the acetabular labrum tears. The stage ]@l A was more common than other types(60.0%). All patients except two were improved by the diagnosis and treatment of an acetabular labrum tear(77.8%). Six patients were treated with arthroscopic debridement and open resection and three patients treated arthroscopically. So, we encouraged arthroscopy of the hip to confirm the diagnosis and treatment of the acetabular labrum tear.

비구순 파열

황득수(Deuk-Soo Hwang),권순태(Soon-Tae Kwon),이원석(Won-Sok Lee),김원중(Weon-Joong Kim) 대한정형외과학회 2000 대한정형외과학회지 Vol.35 No.1

수근 주상골 불유합에 대한 수술적 치료

신현대(Hyun-Dae Shin),이광진(Kwang-Jin Rhee),이준규(Jun-Kyu Lee),이원석(Won-Sok Lee),김진수(Jin-Soo Kim),김상범(Sang-Bum Kim) 대한정형외과학회 1997 대한정형외과학회지 Vol.32 No.4

외상성 주관절 구축의 수술적 치료

신현대,이원석 충남대학교 의과대학 지역사회의학연구소 1996 충남의대잡지 Vol.23 No.2

The eleven consecutive patients who had contracture of the elbow joint were treated by anterior capsulectomy and distraction arthroplasty without fascial interposition or anterior capsulectomy only. The ten elbows were post-traumatic contracture, and the one elbow was the ankylosis due to prolonged immoobilization after rain injury. Five patients were treated with distraction arthroplasty by modified Mayo Clinic Device and six patients underwent anterior capsulectomy under general or regional anesthesia. The mean preoperative arc of the total motion was 52 degrees(from 44 to 92 degrees of flexion). At follow-up examination, twelve to forty months postoperatively, of eleven patients, the mean arc of the total motion was 108 degrees (from 14 to 122 degrees of flexion). There were seven complications in seven of the eleven patients. Of these, the two were heterotopic ossification recurred in the posterior capsule of the elbow joint, so subsequently the ulnohumeral arthroplasty was performed at postoperative 8 months and 30 months later. The transient ulnar nerve injuries were occurred in two patients. The injured nerve dysfunction was resolved spontaneously. Two patients occured superficial wound infection. The pin site infection was occurred in one patient. The infection was subsided by dressing and antibiotics. Nine of the eleven patients who were followed for average 19 months satisfied with the results of the procedure because of the improved activity in carrying out daily life. No patients showed aggravation of pain. The three severely unstable elbow was improved from 3 points to 1 point on stability points. It was concluded that results of distraction arthroplasty and anterior capsulectomy could be gratifying and the range of motion of elbow was improved Significantly. But the technique is demanding and the rate of complications such as ulnar paresthesia or pin site infection is high especially distraction arthroplasty.

척추 전방 전위증 환자의 자기공명 영상 소견에서 보이는 추체종판의 변화

안재성,이준규,황득수,이원석 충남대학교 의과대학 지역사회의학연구소 1997 충남의대잡지 Vol.24 No.2

We reviewed the 156 magnetic resonance of lumbar spine with spondylolisthesis in simple X-ray and analysed relationship of the type of spondylolisthesis with bone marrow change in lumbar MRI and low back pain, instability of lumbar spine and prognosis. The patients with no bone marrow change were excluded in our study. Bone marrow changes were classified into 3 types by Moddic methods. Type I is low signal in T1 image and high signal in T2 image, type Ⅱ is high signal in T1 image and isodense or slight increased signal in T2 and type 2Ⅲ is decreased signal in both T1 and T2 image. Displacement over 3㎜ in motion view is defined as instability. Pain was scored by JOA scoring system. 22(14.1%) of 156 patients had local bone marrow change of vertebral end-plate. Of 22 patients, levels of lesion were 28 levels. 14 levels were isthmic type, 6 levels were degenerative type and 8 levels were retrolisthesis, respectively. Isthmic type had type Ⅰ or Ⅲ In 8(57.1%) levels, instability in 7(50.0%) levels and significant pain(0 of 1 point) in 9(69.2%) patients. Degenerative or retrolisthesis had type Ⅱ in 10(71.4%) levels, instability in 1(7.1%) level and significant pain in 4(44.4%) patients. Unstable and more symptomatic type of spondylolisthesis was associated with type Ⅰ or Ⅲ change of bone marrow in MRIm and may be teated more aggressively. Type Ⅰ or Ⅲ of bone marrow change is associated with segmental instability and low back pain and has a poor prognosis, but type Ⅱ are present in more stable and chronic disease. We concluded that isthmic type was more associated with pain, instability and type Ⅰor Ⅲ change, while degenerative or retrolisthesis type were more stable and painful and associated with type Ⅱ change.

요추 핵자기 공명 영상 소견에서 보이는 추체종판 인접 추체골의 변화

이준규,안재성,권순태,안철세,이원석 대한척추외과학회 1996 대한척추외과학회지 Vol.3 No.2

Study design. 254 magnetic resonance imaging of lumbar spine with degenerative disc disease and chronic low back pain were assessed on vertebral endplate signal change. Objective. This study was undertaken to retrospectively analyzed the relationship of vertebral endplate signal change in lumbar magnetic resonance imaging with low back pain, radiating pain and hypermobility of lumbar spine. Summary of Background Data. Vertebral endplate signal change may result from edema, inflammation or vascular change, but exact pathophysiology and relationshop with clinical finding was uncertain. Methods. We reviewed the 254 magnetic resonance imaging of lumbar spine. We excluded patients who had had previous lumbar disc surgery including LASER discectomy, chemonucleolysis and those with vertebral endplate lesions, such as ostemoyelitis or tumorous condition. Abnormalties on endplate were classified into type A with decreased signal intensities on T1 weighted spin echo image, and type B with increased signal intensities on vertebral endplates. Results. 31(12%) of 254 patients had focal alternations in the endplates and bone marrow adjacent to degenerative disc. Of 31 patients, Sixteen was type A, fifteen was type B. Fourteen(87%) patients in type A had low back pain, while ten(67%) patients in type B. Lateral motion views of lumbar spine showed hepermobility over 3mm in ten patients(63%) with type A, and in six patients(40%) with type B. Spondyloithesis was most common disease associated with endplate and bone marrow changes. 15 cases were spondylolisthesis, of these, 10 cases were type A, and 5 cases were type B. Conclusions. We concluded that type A is associated with segmental hypermobility and low back pain, while type B were more common in patients with stable degenerative disc disease.