• Journal of The Geomorphological Association of Korea
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• v.15 no.2
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• pp.85-94
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• 2008

This study is to construe spatio-temporal characteristics of temperature in cities and changes of climatical regions in analyzing a change of Korea Peninsular climate. We used daily mean air temperature data which was collected in South and North Korea for the past 34 years from 1974 to 2007. We created temperature map of 500m resolution using Inverse Distance Weight in application with adiabatic lapse rate per month in linear relation with height and temperature. In the urbanization area, the data analyzed population in comparison with temperature changes by the year. An annual rising rate of temperature was calculated $0.0056^{\circ}C$, and the temperature was increased $2.14^{\circ}C$ from 1974 to 2107. The south climate region in Korea by the Warmth index was expanded to the middle climate region by the latitude after 1990s. A rise of urban area in mean temperature was $0.5-1.2^{\circ}C$, Seoul, metropolitan and cities which were high density of urbanization and industrialization with the population increase between 1980s and 1990s. In case of North Korea, Cities were Pyeongyang, Anju, Gaecheon, Hesan. A rise in cities areas in mean temperature has influence on vegetation, especially secondary growth such as winter buds of pine trees appears built-up area and outskirts in late Autumn. Finally, nowaday we confront diverse natural events over climatical changes, We need a long-term research to survey and analyze an index on the climatical changes to present a systematic approach and solution in the future.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.381-381
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• 2017

수자원 분야에 대한 기후변화의 영향은 홍수, 가뭄 등 극치 수문사상의 증가와 변동성 확대를 초래하는 것으로 알려져 있으며, 이에 따라 예년에 비해 발생빈도 및 심도가 증가한 가뭄에 대한 모니터링 및 피해경감을 위해 정부에서는 국민안전처를 비롯한 관계기관 합동으로 생활 공업 농업용수 등 분야별 가뭄정보를 제공하고 있다. 국토교통부와 환경부는 생활 및 공업용수 분야의 가뭄정보 제공을 위해 광역 지방 상수도를 이용하는 급수 지역과 마을상수도, 소규모급수시설 등 미급수지역의 용수수급 정보를 분석하여 가뭄 분석정보를 제공 중에 있다. 하지만, 미급수지역에 대한 가뭄 예?경보는 기준이 되는 수원정보의 부재로 기상 가뭄지수인 SPI6를 이용하여 정보를 생산하고 있다. 기상학적 가뭄 상황과 물부족에 의한 체감 가뭄은 차이가 있으며, 미급수 지역의 경우 지하수를 주 수원으로 사용하는 지역이 대부분으로 기상학적 가뭄지수인 SPI6를 이용한 가뭄정보로 실제 물수급 상황을 반영하기는 부족한 실정이다. 따라서 본 연구에서는 미급수지역의 주요 수원인 지하수의 수위 상황을 반영한 가뭄모니터링 기법을 개발하고자 하였으며, 가용량 분석이 현실적으로 어려운 지하수의 특성을 고려하여 수위 거동의 통계적 분석을 통해 가뭄을 모니터링 할 수 있는 방법으로 접근하였다. 국가지하수관측소 중 관측기간이 10년 이상이고 강우와의 상관성이 높은 관측소들을 선정한 후, 일수위 관측자료를 월별로 분리하여 1월~12월 각 월에 대해 핵밀도 함수 추정기법(kernel densitiy estimation)을 적용하여 월별 지하수위 분포 특성을 도출하였다. 각 관측소별 관측수위 분포에 대해 백분위수(percentile)를 이용하여, 25%~100% 사이는 정상, 10%~25% 사이는 주의단계, 5%~10% 사이는 심한가뭄, 5% 이하는 매우심함으로 가뭄의 단계를 구분하였다. 각 백분위수에 해당하는 수위 값은 추정된 Kernel Density와 Quantile Function을 이용하여 산정하였고, 최근 10일 평균수위를 현재의 수위로 설정하여 가뭄의 정도를 분류하였다. 분석된 결과는 관측소를 기점으로 역거리가중법(inverse distance weighting)을 통해 공간 분포를 시켰으며, 수문학적, 지질학적 동질성을 반영하기 위하여 유역도 및 수문지질도를 중첩한 공간연산을 통해 전국 지하수 가뭄상태를 나타내는 지하수위 등급분포도를 작성하였다. 실제 가뭄상황과의 상관성을 분석하기 위해 언론기사를 통해 확인된 가뭄시기와 백문위수 25%이하로 분석된 지하수 가뭄시기를 ROC(receiver operation characteristics) 분석을 통해 비교 검증하였다.

• Korean Journal of Psychosomatic Medicine
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• v.23 no.2
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• pp.79-85
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• 2015

Objectives : To investigate clinical and symptomatic differences among motoric subtypes of delirium. Methods : A total of 256 patients referred to psychiatric consultation services for delirium due to general medical condition were assessed retrospectively. Motoric subtypes were determined according to Lipowski's criteria for hyperactive, hypoactive and mixed subtypes. All patients were evaluated according to Delirium Rating Scale-Revised-98(DRS-98-R) by trained psychiatrists to obtain symptomatic profiles of delirium. Results : Hyperactive subtype were 50.8%(n=130), mixed 46.1%(n=118) and hypoactive 3.1%(n=8). Hyperactive patients were younger than mixed subtype($69.62{\pm}13.976$ vs. $73.97{\pm}11.569$, p=0.022) and received antipsychotics to manage symptoms of delirium more frequently(83.8% vs. 57.6%, p<0.001). Hyperactive patients had higher DRS-R-98 scores on both noncognitive($7.14{\pm}3.543$ for hyperactive, $5.62{\pm}3.279$ for mixed subtype) and cognitive subscales($10.00{\pm}3.574$ for hyperactive, $6.38{\pm}2.875$ for hypoactive, $7.43{\pm}3.771$ for mixed subtype, p<0.001). Conclusions : We demonstrated that clinical and symptomatic profiles were different across motoric subtypes in delirium. Diagnostic and therapeutic approach should be made differently according to motoric subtypes of delirium and special attention is needed not to underestimate or delay treatment in specific motoric subtype of delirium.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.782-793
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• 2022

The rise in chronic disease not only has a negative effect on people's lives, but it also increases the cost of medical care owing to the increased usage of medical care as health and medical technology improves, life expectancy rises, and rapid population ageing. In such context, this study examined the difference in the disease cost of hypertension according to demographic information and the effect of the initial diagnosis age and treatment period on the cost. This study used the Korean Health Panel Survey from 2010 to 2017, and selected subjects based on health insurance beneficiaries between the ages of 30 and under 80. With the selected data, the direct and indirect costs of disease loss were calculated according to the cost of illness approach, and we constructed a disease-loss ratio cohort considering the age of diagnosis and time of treatment for hypertension. From the results of the study, the annual cost of disease loss for hypertensive patients differed by gender by 110,107 won, and it was found that the cost increased by 1.8 times as the treatment time increased. In addition, when comparing disease loss ratios between the same age groups, it was found that the disease loss ratios between those in their 60s and 70s were affected by treatment time. This study confirmed that hypertension significantly affects the cost of the disease, and not only requires early diagnosis and management, but also preventive efforts to lower the incidence of hypertensive disease must be strengthened.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.269-282
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• 2007

The purpose of this study is to investigate the causes of the dramatic process in forest policies from July of 1972 to June of 1973. In 1972, the core forest problem calling for an immediate solution was the severe forest degradation such as a low growing stock ($11m^3/ha$) and lots of non-tree forest land corresponding to 12% of total forest land. There could have been various approaches to solve the problem at that time. By the end of 1972, the Korean government was afoot to choose the management-oriented approach to carry out reforestation as a part of forest management. In order to implement this approach, the Korean government established the Forest Development Law enforcing establishment of the Forest Management Corporation as a public organization to carry out forest management in the special development land. However, the Korean government changed the management-oriented approach into the administration-oriented approach to carry out reforestation as a part of forest greening in order to rehabilitate severe degraded forests as soon as possible in early 1973. The Forestry Administration (refer to Forest Service) was transferred from the Department of Agriculture and Forestry to the Department of Interior for the efficient rehabilitation in advance, before the 1st 10-year National Greening Project. After the organization's transfer, the government established the 1 st 10-year National Greening Project aiming to reforest one million ha from 1973 to 1982 to use activities like the national greening campaign and the administrative organization mobilization including police force. Reforestation policy as a part of forest management lost effect due to the greening-oriented approach choice. Moreover, the Government struggled to provide 20 billion won for the establishment of the Forest Management Corporation. After all, on March 5th of 1973, the management-oriented approach dropped a curtain deleting the clauses defining the establishment of the Forest Management Corporation. Park, Chung-hee who was the then president of Korea might have felt the 'time restriction' to lose no time to habilitate degraded forests. Due to his awareness, the approach regarding reforestation was changed into administration-oriented activities. The president's awareness was considered as an invisible cause at that time.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1282-1286
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• 2006

Purpose : The causes of prolonged fever have changed during the years and are influenced by age, geographic location and availability of diagnostic facilities/techniques. The aim of the present study was to determine the causes of prolonged fever, to know the proportion and outcomes of undiagnosed children. Methods : We reviewed patients with fever persisting for more than 2 weeks in duration, with documented temperatures of $38^{\circ}C$ on several occasions, or uncertain diagnosis after intensive study of 1 week duration in other hospitals who were admitted to Pusan National University Hospital during the period from July 1999 to June 2004. Results : Fifty-four (59.0 percent) were boys and thirty-seven (41 percent) were girls. Forty-six cases were less than 6 years and 45 cases were more than 6 years; the mean age was $6.48{\pm}6.56years$. In 62 cases (68.1 percent), the fever had persisted for 2 to 3 weeks before admission and in 26 cases (28.6 percent), had lasted longer than a month. Final diagnosis had been reached in 66 of 91 children (72.5 percent). The most common cause was infection (38/91), followed by collagen vascular disease (12/91), immune deficiency (3/91), neoplasia (2/91), and miscellaneous disease. Tuberculosis was the most common infectious cause. The causes of fever were not revealed in 25 cases. Outcome on discharge were as follows; 77 cases (84.6 percent) were improved, 10 cases (11.0 percent) discharged without improvement and 4 cases (4.4 percent) expired. Conclusion : The most common cause of prolonged fever in Korean children remains infection, but the incidence of infection was decreased as compared with previous studies. Tuberculosis is the most common among infectious causes. As Kikuchi disease (subacute necrotizing lymphadenitis) represented a significant cause of prolonged fever, it should be considered if a patient has neutropenia with lymphadenopathy. Undiagnosed patients with prolonged fever (27.5 percent) have increased over previous studies.

• Journal of Intelligence and Information Systems
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• v.29 no.1
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• pp.249-263
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• 2023

Collaborative Filtering, a representative recommendation system methodology, consists of two approaches: neighbor methods and latent factor models. Among these, the latent factor model using matrix factorization decomposes the user-item interaction matrix into two lower-dimensional rectangular matrices, predicting the item's rating through the product of these matrices. Due to the factor vectors inferred from rating patterns capturing user and item characteristics, this method is superior in scalability, accuracy, and flexibility compared to neighbor-based methods. However, it has a fundamental drawback: the need to reflect the diversity of preferences of different individuals for items with no ratings. This limitation leads to repetitive and inaccurate recommendations. The Adaptive Deep Latent Factor Model (ADLFM) was developed to address this issue. This model adaptively learns the preferences for each item by using the item description, which provides a detailed summary and explanation of the item. ADLFM takes in item description as input, calculates latent vectors of the user and item, and presents a method that can reflect personal diversity using an attention score. However, due to the requirement of a dataset that includes item descriptions, the domain that can apply ADLFM is limited, resulting in generalization limitations. This study proposes a Generalized Adaptive Deep Latent Factor Recommendation Model, G-ADLFRM, to improve the limitations of ADLFM. Firstly, we use item ID, commonly used in recommendation systems, as input instead of the item description. Additionally, we apply improved deep learning model structures such as Self-Attention, Multi-head Attention, and Multi-Conv1D. We conducted experiments on various datasets with input and model structure changes. The results showed that when only the input was changed, MAE increased slightly compared to ADLFM due to accompanying information loss, resulting in decreased recommendation performance. However, the average learning speed per epoch significantly improved as the amount of information to be processed decreased. When both the input and the model structure were changed, the best-performing Multi-Conv1d structure showed similar performance to ADLFM, sufficiently counteracting the information loss caused by the input change. We conclude that G-ADLFRM is a new, lightweight, and generalizable model that maintains the performance of the existing ADLFM while enabling fast learning and inference.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.107-112
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• 2004

Purpose: We described our experience with subungual exostosis in the foot for which we used different surgical technique according as location and size of lesion and revealed excellent results. Materials and Methods: We experienced 12 cases of subungual exostosis that were treated surgically and followed them more than one year between October 1995 and July 2003. There were nine females and three males. The average age of patients at surgery was 13.4 years. Duration of symptoms was 20.3 months on average. The lesion involved the hallux in nine cases; eight dorsomedial and one dorsolateral aspect of distal phalangeal bone. It involved the second, the third, and the fifth toe in one each; all central aspect of dorsum of distal phalanx. We used surgical technique that involves approaching the exostosis under the nail to preserve nail coverage for lesion in the hallux. The nails were extracted totally but preserved nail bed as much as possible in other toes. Results were based on appearance of the regenerated nail and presence of recurrence. Excellent results were those in which the nail appeared nearly normal and there was no clinical or radiographic evidence of recurrence. Good results were associated with a minor nail deformity such as ridging, and no evidence of recurrence. Fair results had obvious nail deformity or a minimal asymptomatic recurrence that was discernable only on radiograph. Poor results were associated with a clinically evident symptomatic recurrence. Results: When the lesion involved hallux, there were six excellent and two good results, and one poor result. All cases that involved other toes revealed good results. Conclusion: We suggest that different surgical technique might be applied according as location and size of the lesion to achieve satisfactory results for subungual exostosis in the foot.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.56-63
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• 2006

Purpose : This study was designed to document the etiologies and the characteristics of parapneumonic effusion in children. Methods : During a 17-year period from 1987 to 2004, parapneumonic effusion was confirmed in 86 children at Gyeongsang National University Hospital. The clinical records of these children were reviewed and radiological findings and laboratory data, especially results of thoracentesis, were analyzed retrospectively. Results : M. pneumoniae(34 subjects) was the most common pathogen at all over age, especially above 1-years-old. There were diagnosed with clinical characteristics and serologic tests. The $2^{nd}$ most common pathogen revealed non tuberculous bacteria(14 subjects). A species of bacteria at no tuberculous bacteria revealed S. aureus(5), S. pneumoniae(3), P. aeroginosa(3), other staphylococcus (2), and K. pneumoniae(1). There were confirmed with sputum culture or pleural fluid culture or blood culture. S. aureus was most common pathogen in infants. The $3^{rd}$ common pathogen was M. tuberculosis(7). There were confirmed with skin tuberculin tests and AFB stains. Another that was classified as a non bacteria was adenovirus(2). Complications of parapneumonic effusion such as pleural thickness occurred on M. tuberculosis(1). Non tuberculous bacteria, especially S. aureus revealed a serious predominance of polymorphocyte at pleural fluid, and lowest pleural pH and glucose, and highest pleural protein and LDH. Tuberculosis revealed high pleural protein and LDH. Conclusion : Age and chemistries of pleural fluid might be helpful in differentiating various etiologies of parapneumonic effusion. If there were suspicious of tuberculosis and non-tuberculous bacteria, more aggressive approaches were needed to prevent complication.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.510-517
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• 1999

Background: Total anomalous pulmonary venous connection (TAPVC) is still one of the more challenging congenital heart defects in newborns and young infants. The purpose of the study is to evaluate the early and midterm results of the surgical corrections for patients in early infancy with isolated TAPVC. Material and Method: Hospital records of 15 consecutive patients in early infancy (January 1993 to August 1998) were retrospectively reviewed. There were 8 boys and 7 girls whose ages ranged from 4 days to 3.5 months (median age 22 days). Their body weight ranged from 1.75 kg to 4.9 kg (mean 3.54 kg). The abnormal anatomical connections were supracardiac in 11, cardiac in 3, and infracardiac in 1. In 6 patients (40%), the pulmonary venous drainage was obstructive. Total circulatory arrest was used in 13 patients. Anastomosis between the common pulmonary vein and the left atrium was performed with a continuous suture technique using a fine nonabsorbable polypropylene suture through a lateral approach behind the right atrium. Result: There was one hospital death (6.5%) caused by a sepsis 17 days after the operation in a neonate who had supracardiac drainage and was dependent on a ventilator preoperatively. There were 2 late deaths. One died sudde`nly of an unknown cause at home 2.5 years after the operation and the other died of a recurrent pulmonary hypertension 3 months after the reoperation due to pulmonary venous obstruction (PVO). Two patients required reoperations because of PVO 5 months and 10 months respectively after the initial operation. Of these patients, one patient is alive at the present time with persistent pulmonary hypertension. All survivors without postoperative PVO (78.6%) were in NYHA functional class I at mean follow-up of 25.8 months (0.5∼67 months). Conclusion: Surgical correction of TAPVC in early infancy can be performed at low risk. However, there were 2 postoperative PVOs (14.3%) which had bad results. The survivors without postoperative PVO had excellent functional status.