• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.329-352
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• 2022

It is reported that particulate matter(PM) penetrates the lungs and blood vessels and causes various heart diseases and respiratory diseases such as lung cancer. The subway is a means of transportation used by an average of 10 million people a day, and although it is important to create a clean and comfortable environment, the level of particulate matter pollution is shown to be high. It is because the subways run through an underground tunnel and the particulate matter trapped in the tunnel moves to the underground station due to the train wind. The Ministry of Environment and the Seoul Metropolitan Government are making various efforts to reduce PM concentration by establishing measures to improve air quality at underground stations. The smart air quality management system is a system that manages air quality in advance by collecting air quality data, analyzing and predicting the PM concentration. The prediction model of the PM concentration is an important component of this system. Various studies on time series data prediction are being conducted, but in relation to the PM prediction in subway stations, it is limited to statistical or recurrent neural network-based deep learning model researches. Therefore, in this study, we propose four transformer-based models including spatiotemporal transformers. As a result of performing PM concentration prediction experiments in the waiting rooms of subway stations in Seoul, it was confirmed that the performance of the transformer-based models was superior to that of the existing ARIMA, LSTM, and Seq2Seq models. Among the transformer-based models, the performance of the spatiotemporal transformers was the best. The smart air quality management system operated through data-based prediction becomes more effective and energy efficient as the accuracy of PM prediction improves. The results of this study are expected to contribute to the efficient operation of the smart air quality management system.

• Journal of the Korean Orthopaedic Association
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• v.54 no.4
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• pp.309-316
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• 2019

Purpose: This study examined the residential environment and accessibility of rehabilitation for cerebral palsy (CP) to identify the problems with residential laws pertaining to the disabled and provide basic data on the health legislation for the rights of the disabled. Materials and Methods: The literature was searched using three keywords: residence, rehabilitation, and accessibility. Two items were selected: residential environment and rehabilitation accessibility. The questionnaire included 51 items; 24 were scored using a Likert scale and 27 were in the form of multiple-choice questions. Results: This study included 100 subjects, of which 93 lived at home and seven lived in a facility. Of these 93 subjects, 65% were living in apartments, usually two or more floors above ground, and 40% of them were living without elevators. According to the Gross Motor Function Classification System, subjects with I to III belonged to the ambulatory group and IV, V were in the non-ambulatory group. Subjects from both groups who lived at home found it most difficult to visit the rehabilitation center by themselves. In contrast, among those who lived at the facility, the ambulatory group found it most difficult to leave the facility alone, while the non-ambulatory group found it most difficult to use the toilet alone. Moreover, 83% of respondents thought that rehabilitation was necessary for CP. On the other hand, 33% are receiving rehabilitation services. Rehabilitation was performed for an average of 3.6 sessions per week, 39 minutes per session. Conclusion: There is no law that ensures secure and convenient access of CP to higher levels. Laws on access routes to enter rooms are insufficient. The disabled people's law and the disabled person's health law will be implemented in December 2017. It is necessary to enact laws that actually reflect the difficulties of people with disabilities. Based on the results of this study, an investigation of the housing and rehabilitation of patients with CP through a large-scale questionnaire will necessary.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.45-51
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• 2019

Purpose: The clinical and radiological results of patients with type 3 talar neck fractures treated with the anteromedial approach using medial malleolar osteotomy and large distractor were analyzed retrospectively. Materials and Methods: From March 2009 to August 2016, 12 patients with a type 3 talar neck fracture, who underwent the anteromedial approach using a medial malleolar osteotomy and large distractor and who could be followed-up for more than 12 months after the operation, were examined. The patients were examined for the presence of Hawkins signs by anteroposterior and lateral radiographs and osteonecrosis by magnetic resonance imaging (MRI) on the postoperative 3 months. Subsequently, every 3 months, radiographic union was assessed by a simple radiograph and clinical symptoms. Twelve months postoperatively, posttraumatic arthritis was assessed and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was analyzed. Results: In 7 cases, osteonecrosis was found on MRI performed 3 months after surgery. On the other hand, at the 12 months follow-up, all of them obtained AOFAS scores of 83.86±4.53 without surgical treatment. Radiographic union was achieved in all cases. The mean union period was 5.3 months. In 10 cases, traumatic arthritis was found after the radiographical and clinical evaluation. In addition, all of them could carry on everyday life by conservative treatment. The AOFAS ankle-hindfoot score was measured to be 85.17 on average. Other complications included superficial wound infection in 2 cases. Conclusion: An anteromedial approach using a medial malleolar osteotomy and a large distractor in the surgical treatment of patients with type 3 talar neck fractures can achieve anatomical reduction of the displaced fragment without a lateral dissection. This is considered to be another good surgical option.

• Journal of the Korean Orthopaedic Association
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• v.54 no.2
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• pp.164-171
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• 2019

Purpose: A dedifferentiated chondrosarcoma is a rare lethal tumor characterized by a low grade chondrosarcoma juxtaposed with a high grade dedifferentiated sarcoma, such as osteosarcoma, fibrosarcoma. The aim of our study was to document the clinical manifestation and oncologic outcomes of a dedifferentiated chondrosarcoma. Materials and Methods: This study identified 11 patients who were diagnosed and treated for dedifferentiated chondrosarcoma between January 2007 and December 2016. The identified cohort was then reviewed regarding age, sex, symptom onset, tumor location, magnetic resonance imagings (MRIs), surgical margin, and pathologic diagnosis. The time to local recurrence and/or metastasis, follow-up duration, and the patients' final status were analyzed. Results: The patients were comprised of 7 males and 4 females with a mean age of 54 years (range, 33-80 years). The location of the tumor was in the femur in 6 cases, pelvis in 4 cases, and metatarsal in 1 case. The average tumor diameter was 12.7 cm (range, 6.0-26.1 cm). At the time of diagnosis, 2 patients showed pathologic fracture; 1 patient was Enecking stage IIA, 9 patients were stage IIB, and 1 patient was stage III. Eight patients were classified as a primary dedifferentiated chondrosarcoma and 3 patients were secondary. One of the primary lesions was misinterpreted initially as a low grade chondroid lesion by MRI and underwent curettage. Local recurrence occurred in 8 cases and distant metastasis occurred in 10 cases with a mean duration of 8 months (range, 2-23 months) and 7 months (range, 1-32 months), respectively. The three-year overall survival of patients with dedifferentiated chondrosarcoma was 18%, and 10 patients died due to disease progression. Conclusion: Dedifferentiated chondrosarcoma developed lung metastases in the early period of the clinical courses and the prognosis was dismal.

• Journal of the Korean Orthopaedic Association
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• v.52 no.1
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• pp.40-48
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• 2017

Purpose: Soft tissue reconstruction of a defect around the foot and ankle is a particularly challenging procedure due to the anatomical and functional characteristics of this area. Hence, only a limited number of treatment options are available. Moreover, if patients wish to avoid additional scars on the ipsilateral lower leg for cosmetic reasons, even fewer options are available for treatment. The authors used an anterolateral thigh perforator flap for soft tissue defects in this area, when other surgical options were inadequate. The aim of this study was to report the clinical results and the efficacy of this procedure. Materials and Methods: Sixteen cases of soft tissue defects around the foot and ankle were included. Participants included 12 male and 4 female subjects, and the mean age was 34 years. The most common cause of defect was acute trauma, and the average follow-up period was 33 months. Flap survival time, surgical complications, and ambulation status at the final follow-up stage were evaluated. Results: All 16 flaps successfully survived, except for one case with partial flap necrosis that was thought to be due to weight bearing earlier than scheduled. All patients were able to walk independently without any aid at the final follow-up stage. No patients showed other significant surgical complications. Conclusion: The anterolateral thigh perforator flap is a good alternative for soft tissue defects of the foot and ankle, when other options are not applicable. This study also demonstrated that surgery using an anterolateral thigh perforator flap is safe and highly reliable.

• Journal of the Korean Orthopaedic Association
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• v.52 no.1
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• pp.33-39
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• 2017

Purpose: Surgical risks associated with the resection of osteochondroma around the proximal tibia and fibula, as well as the proximal humerus have been well established; however, the clinical presentation and optimal surgical approach for osteochondroma around the lesser trochanter have not been fully addressed. Materials and Methods: Thirteen patients with osteochondroma around the lesser trochanter underwent resection. We described the chief complaint, duration of symptom, location of the tumor, mass protrusion pattern on axial computed tomography image, tumor volume, surgical approach, iliopsoas tendon integrity after resection, and complication according to the each surgical approach. Results: Pain on walking or exercise was the chief complaint in 7 patients, and numbness and radiating pain in 6 patients. The average duration of symptom was 19 months (2-72 months). The surgical approach for 5 tumors that protruded postero-laterally was postero-lateral (n=3), anterior (n=1), and medial (n=1). All 4 patients with antero-medially protruding tumor underwent the anterior approach. Two patients with both antero-medially and postero-laterally protruding tumor received the medial and anterior approach, respectively. Two patients who underwent medial approach for postero-laterally protruded tumor showed extensive cortical defect after resection. One patient who received the anterior approach to resect a large postero-laterally protruded tumor developed complete sciatic nerve palsy, which was recovered 6 months after re-exploration. Conclusion: For large osteochondromas with posterior protrusion, we should not underestimate the probability of sciatic nerve compression. When regarding the optimal surgical approach, the medial one is best suitable for small tumors, while the anterior approach is good for antero-medial or femur neck tumor. For postero-laterally protruded large tumors, posterior approach may minimize the risk of sciatic nerve palsy.

• Korean Association of Arts Management
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• no.49
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• pp.5-35
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• 2019

The main purpose of this study was to use semantic network analysis to examine the international trend of arts management and other studies pertinent to this field. The subject was based on 357 keywords listed on the abstract of 185 research papers in the International Journal of Arts Management. To examine the most current trends of arts management based studies the time frame was restricted from 2008 to 2017. To briefly summarize the result, first, 'museum' was the most frequently appeared keyword. This was followed by 'performing arts' and 'arts' with more than 20 appearances. 'Motion picture industry' and 'theater' were the next frequently appeared keywords. 'Customer behavior' and 'market strategy', keywords related to management, were also included in the high ranked group along with art related keywords. Second, yearly research trend shows that arts management has been regularly studied for past ten years with average of 19 research papers with about 53 keywords. Keywords such as 'museum' and 'performing arts' has been regularly studied for past ten years. 'Culture', 'theater' and 'motion pictures industry' does not regularly appear in the result of yearly research trend but nevertheless they have sparsely made an appearance along the past decade. 'Art gallery' has not been cited till 2011 but from 2012 it was regularly and continuously made an appearance in the yearly research trend. Overall, the yearly trend result shows that the trend of international arts management studies within IJAM, was at first centered on fine arts but as the time passed there has been diversified keywords related to management. Third, 'performing art' and 'art' has the highest link frequency(34). Fourth, density result was 0.039 which shows that the keyword density is not very high. Fifth, 'art', 'performing art', 'museum', 'theater' and 'brand' were positioned in the middle when looking at the visualized version of centrality result. This means that these five keywords has the highest centrality among other keywords.

• Korea Trade Review
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• v.42 no.5
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• pp.137-159
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• 2017

This study divides manufacturing in 18 countries including Korea, China, Japan and OECD countries into 11 areas and estimates and compares the technological efficiency of each industry. The traditional view of productivity is to increase production capacity through technological innovation or process innovation, but it is also influenced by the technological efficiency of production process. A Stochastic Frontier Production Model (SFM) is a representative method for estimating the technical efficiency of such production. First, as a result of estimating the production function by setting the output variable as total output or value-added, in both cases, the output increased significantly in all manufacturing sectors as inputs of labor, capital, and intermediate increased. On the other hand, R&D investment has a large impact on output in chemical, electronics, and machinery industries. Next, as a result of estimating the technological efficiency through the production function, when the total output is set as the output variable, the overall average of each sector is 0.8 or more, showing mostly high efficiency. However, when value-added was set, Japan had the highest level in most manufacturing sectors, while other countries were lower than the efficiency of the total output. Comparing the three countries of Korea, China and Japan, Japan showed the highest efficiency in most manufacturing sectors, and Korea was about half or one third of Japan and China was lower than Korea. However, in the food and electronics sectors, China is higher than Korea, indicating that China's production efficiency has greatly improved. As such, Korea is not able to narrow its gap with Japan relatively faster than China's rapid growth. Therefore, various policy supports are needed to promote technology development. In addition, in order to improve manufacturing productivity, it is necessary to shift to an economic structure that can raise technological efficiency as well as technology development.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.211-222
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• 2016

This study was conducted to investigate the physico-chemical meat quality and sensory properties of Holstein steers(n=18, 4 months old, average body weight 160kg) which were divided into 3 groups and fed 2 different energy levels of total mixed rations(TMR)(T1, TDN 74~84%; T2, TDN 77~85%) until 18, 20 or 22 months old, respectively. For loin muscles, 22-month group of T1 and 20- and 22-month groups of T2 had higher fat contents than the other groups (P<0.05). T2 had higher WHC values for 18-month groups among 3 feeding groups (P>0.05). In sensory properties, T1 had higher tenderness, flavor-likeness and overall likeness for 20-month group than the other groups (P<0.05). T2 had higher tenderness, juiciness, flavor likeness and overall likeness in 20- and 22-months groups than 18-month group (P<0.05). For top round muscles, 22-month group had higher fat contents than the other groups of T1 and T2 (P<0.05). T1 had higher in redness(a* value) and yellowness (b* value) of 22-month group (P<0.05). T2 had higher WHC values, lower WBS and CL values in 18-month group than the other groups (P<0.05). In sensory properties, T1 had higher tenderness for 18 and 20-month groups and overall likeness (P<0.05). T2 had higher tenderness in 18-month group. The results of this study showed that longer feeding of agricultural by-product TMR increased the intramuscular fat contents, however, the 18 and 20-months finishing groups were advantageous for the meat quality and sensory properties of Holstein steers.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.163-172
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• 2016

Four growing Hanwoo cattle weighing 200±11.7kg were used within 4×4 Latin square design to establish nutrient requirements for Hanwoo growing steers under severe heat stress. The steers were fed four different energy level diets; 100%(control), 100%(E100), 115%(E115) and 130%(E130) of energy levels of growing Hanwoo steers based on total digestible nutrient level suggested by the Korea Feeding Standard for Hanwoo using timothy hay and commercial concentrate. The steers in the control were housed with no stress, whereas the steers in the other groups were under severe heat stress. The severe heat stress significantly decreased(p<0.05) true digestibility of dry matter(i.e. control 81.5% vs E100 79.1, E115 77.0 and E130 76.0, respectively). The severe heat stress and different energy intake levels did not affect blood physiological metabolites and body temperature of the growing steers. Based on changes in average daily gain by different energy intake level, the equation(Y=0.235X+115.03) of energy requirement of growing Hanwoo steers without changes in body weight was calculated, indicating that, compared with the present energy intake suggested by Korean feeding standard, 15.03% of dietary energy for maintenance of growing Hanwoo steers under severe heat stress should be increased.