• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.73-79
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• 1986

This study was conducted to evaluate the effects of lead on the incidence of anemia and to find cases with lead poisoning early among female workers who have been exposed to lead occupationally, for one year from August, 1985. The level of blood lead and hemoglobin concentration were observed for 284 female lead workers and 123 female non-lead workers of industries in the Gumi industrial complex in Kyungpook Province. The average age was $20.3{\pm}2.9$years and $21.1{\pm}3.5$ years in lead workers and non-lead workers, respectively. The average working duration was $26.46{\pm}19.26$ months in lead workers. The mean value of blood lead was $30.11{\pm}6.61{\mu}g/100ml$ and $21.86{\pm}3.75{\mu}g/100ml$ in lead workers and non-lead workers, respectively. There were significant differences between two groups. The mean value of hemoglobin concentration was $14.00{\pm}0.57g/100ml$ and $14.03{\pm}0.64g/100ml$ in lead workers and non-lead workers, respectively. Anemia cases were not observed at Hb concentration below 12g/100ml. The percentages of lead workers at Hb concentration ranged 12.0~13.0g/100ml were 4.5%. There was no dose-response relationship between blood lead level and the incidence of anemia. There were no remarkable differences between age and blood lead level as well as Hb concentration, and between working duration and the level of blood lead and hemoglobin.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.2
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• pp.79-86
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• 2014

Objectives : Shift work disorder occurs when you have difficulties adjusting to a work schedule that takes place during a time which most people sleep. Some people may have diverse psychosomatic symptoms, such as sleep problems, depression, anxiety, and headaches even after the shift work schedule ends. The aims of this study are to compare difference of psychosomatic symptoms between rotating shift and daytime working nurse groups. Methods : Volunteer nurses working in a general hospital were recruited in a general hospital. We collected sociodemographic data. We used questionnaires for headache type, headache frequency, and VAS(Visual Analog Scale) for headache intensity, BDI(Beck depression Inventory) and GSAQ(Global Sleep Assessment Questionnaire). We used Mann-Whitney test and Chi-square test for hypothesis testing. Results : Data collected from 84 women nurses. Rotating shift(N=37) working nurses showed younger, more unmarried, and shorter work periods than daytime working nurses (N=47). Also rotating shift group showed more problems of headache, insomnia, excessive daytime sleepiness, depression and anxiety than daytime group. The above results were statistically significant. Conclusions : The rotating shift work women nurses produced more headache, insomnia, excessive daytime sleepiness, depression, and anxiety than daytime working ones.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.77-83
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• 2010

In this study, we analyzed the combustion characteristics of four different floor covering materials(wood, monorium, laminatedpaper, and varnish-laminated paper) with regard to their ignitibility, thermal characteristics and flame retardancy by using an ignition temperature tester, a dual cone calorimeter, a thermogravimetric analyzer and limited oxygen index, for their fire risk assessment. According to the result, monorium had the lowest ignition temperature of $325^{\circ}C$ and the laminated paper and the varnish-laminated paper promptly ignited before 7s. Further, the wood showed the largest total heat release of $100MJ/m^2$, and the varnish-laminated paper showed the highest peak heat release rate. From the thermogravimetric analysis, it was shown that all specimens underwent rapid weight loss at $300{\sim}400^{\circ}C$. The limit oxygen indices of the laminated paper and the varnish-laminated paper were in the range of 20~21%, while it was 34% for wood. This study enabled us to confirm that wood, laminated paper and varnish-laminated paper have a relatively short ignition time and are easy to burn but they all have low heat release. In contrast, wood showed the lowest fire risk among them and had excellent flame retardancy but with high heat release.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.36-42
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• 2005

Purpose: To investigate the arthroscopic findings, and to evaluate the clinical outcomes of the treatment of posterior internal impingement of the shoulder in baseball players. Materials and Methods: We followed up 5 cases who were diagnosed as posterior internal impingement for the mean 15 months. All of the cases complained of the pain in the posterior shoulder at late cocking, and were positive in the relocation test added by hyper-horizontal abduction at $120^{\circ}$ abduction of the arm. We sutured posterior labral tear and SLAP lesion arthroscopically, and conducted debridement for rotator cuff. Three cases were performed of anterior capsular plication and the other two were performed of thermal capsular shrinkage. Pain, range of motion, and level of return to sports activity were assessed for the results. Results: As to the arthroscopic findings, all the five cases showed the fraying in posterosuperior labrum, and two of them was accompanied with the flap tear in posterosuperior labrum and the other one was accompanied with type 2 SLAP lesion. All the cases showed the fraying in supraspinatus, and one case showed partial tear. Meanwhile, in all the cases, the rotator cuff was impinged to the labrum at $90^{\circ}{\sim}120^{\circ}$ of abduction and external rotation. As to the postoperative results, all the cases did not complain of pain or instability while pitching, and the competition was recovered to be the mean 88%($80{\sim}100%$) of that before the injury. Conclusion: Definite diagnosis for the posterior internal impingement would be possible through arthroscopic examination. Favorable outcomes could be obtained with capsular plication or shrinkage for anterior microinstability and stretching exercise for posterior capsule tightness inducing the internal impingement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.222-227
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• 2020

Pb(Zr,Ti)O₃(denoted as PZT) in the perovskite phase is used as a dielectric, piezoelectric, and super appetizer material owing to its ferroelectric properties. A PZT film was formed by an RF magnetron sputtering process by preparing a target composed of Pb_1.3(Zr_0.52Ti_0.48)O₃. The PZT film was formed by dividing the material into a mono-layer PZT produced continuously with the same sputtering power and a bi-layer PZT produced with two-stage sputtering power. The bi-layer PZT consisted of a lower layer produced under low-power sputtering conditions and an upper layer produced under the same conditions as the mono-layer PZT. XRD revealed small amounts of pyrochlore phase in the mono-layer PZT, but only the perovskite phase was detected in the bi-layer PZT. SEM and AFM revealed the upper part of the bi-layer PZT to be more compact and smooth. Moreover, the bi-layered PZT showed superior symmetry polarization and a significantly reduced leakage current of less than 1×10-5 A/cm². This phenomenon observed in bi-layer PZT was attributed to the induction of growth into a pure perovskite phase by suppressing the formation of a pyrochlore phase in the upper PZT layer where the densely formed lower PZT layer was produced sequentially.

• The Journal of the Korea Contents Association
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• v.7 no.10
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• pp.311-320
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• 2007

This study is to analyze the present condition of internal dance troupes' web sites contents and through this study, we aim at suggesting beneficial plans not only for constructing better web sites and contents for national dance troupes but also for contributing to the development of national dance troupes. In order to achieve this study's object, we selected eight dance troupes that run their own web sites and examined their contents. the conclusions are as following. First, among internal professional dance troupes, Korea National Ballet, Seoul Ballet Theatre and Universal Ballet Company offer the best contents at their home pages and they have the most lively community concerned activities at their internet web sites. Second as for the web sites of municipal(provincial) dance troupes, those of Gyeonggi provincial dance troupe, Daejeon municipal dance troupe, Busan municipal dance troupe, Seoul municipal dance troupe Incheon municipal dance troupe have lots of contents briskly carried on, but those of the others need complementary measures. Third, Seoul ballet theatre and Universal Ballet Company offer lots of information about their activities to satisfy their customers and make the maximum use for public relations ; performance news, the introduction of their members, the story of ballet press reviews, new letters. On the other hand, at the web sites of Metropolitan Dance Theater Provincial Dance Company, there are much fewer contents about their activities which doesn't lead customers to visit their webs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.363-370
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• 2016

The purpose of this study was to determine the effects of speed variations in treadmill training on the thickness of lower extremity muscles. A total of 36 university students were divided into three groups: MVTG (n=12), HVTG (n=12), and ATG (n=12). Subjects in MVTG underwent treadmill training with their own average speed; those in HVTG underwent treadmill training with 130% speed of their own average speed; and those in ATG underwent treadmill training with alteration of speed, between 100% and 130% of their own average speed. Treadmill training was performed for 60 minutes a day, three times per week, for a total of 6 weeks. Ultrasonography was used to compare the muscle thickness between rectus femoris, vastus lateralis, gastrocnemius, and tibialis anterior. The result was as follows: The rectus femoris, vastus lateralis, and gastrocnemius were significantly increased after the training period, and they also were statistically significant in interaction. Moreover, tibialis anterior was also significantly increased. Therefore, compared to the average-speed treadmill training, speed variations had a greater effect on thickening the lower extremity muscles. In the near future, we will conduct a study applying the findings from this study in a rehabilitation program for patients with gait disturbance due to nervous or musculoskeletal system disease.

• Korean Journal of Remote Sensing
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• v.33 no.2
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• pp.231-242
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• 2017

Monitoring of facilities such as roads, dams and bridges is important for their long-term sustainable usage. It has usually suffered with safety and cost problems, which makes more frequent monitoring difficult. As an efficient and economicalsolution to these problems, one may consider the use of smartphone to capture the status of the facilities. To derive quantitative analysis results with the smartphone images for facility monitoring, one should first rectify the images in a way as automatic and economical as possible. In thisstudy, we propose such a rectification method, which rectifiessmartphone images acquired from arbitrary locations based on reference images.In the proposed method, we determine the camera extrinsic parameters of each smartphone images using the reference imagesrather than ground control points, and project the image to the target surface of the facility based on the determined camera parameters. The method were applied to test data acquired from a small dam toward water-area facility monitoring. The experimental results showed that the camera extrinsic parameters were determined with the accuracy of 5 cm and $0.28^{\circ}$ in the position and attitude. The accuracy of the distance measured from the rectified image was evaluated to 10 cm. With the rectified images, one can accurately determine the location and length of the target objects required for facility monitoring.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.1
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• pp.33-50
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• 1994

The Hydrogeologic data of 455 water wells comprising geologic log and aquifer test were analyzed to determine hydrogeologic characteristics of the Cheju island. The groundwater. of the Cheju island is occurred in unconsolidated pyroclastic deposits and crinker interbedded in highly jointed basaltic and andesic rocks as high level, basal and parabasal types under unconfined condition. The average transmissivity and specific yield of the aquifer are at about 29,300㎡/day and 0.12 respectively, The total storage of groundwater is estimated about 44 billion cubic meters. Average annual precipitation is about 3,390 million ㎥ among which average recharge is estimated for 1,494 million ㎥ being equivalent 44.1% of total annual precipitation with 638 million ㎥ of runoff and 1,256 million ㎥ of evapotranspiration. Based on groundwater budget analysis, the sustainable yield is about 620 million ㎥(41% of annual recharge)and rest is discharging into the sea. The geologic logs of recently drilled thermal water wells indicate that very low-permeable marine sediments(Sehwa-ri formation) composed of loosely cemented sandy silt derived from mainly volcanic ashes at the 1st stage volcanic activity of the area is situated at the 120${\pm}$68m below sea level. Another low-permeable sedimentary rock called Seogipo-formation which is deemed younger than the former marine sediment is occured at the area covering north-west and western part of the Cheju island at the ${\pm}$70m below sea level. If these impermeable beds art distributed as a basal formation of fresh water zone of the Cheju island, the most of groundwater in the Cheju island will be para-basal type. These formations will be one of the most important hydrogeologic boundary and groundwater occurences in the area.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1789-1793
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• 2008

전자파표면유속계는 홍수유속측정을 위하여 개발된 기기로 평 갈수기에는 유속측정이 불가하여 프로펠러 유속계를 이용하고 있다. 현재 보급된 전자파표면유속계는 하천의 흐름방향에 나란하게 설치하였을 때에만 유속을 측정할 수 있는 기기의 구조상의 한계성 때문에 교량이 없는 지점에서는 유속측정이 불가하여 유량산정을 할 수가 없다. 또한 편각측정이 불가능하여 기기를 각 측선마다 이동 설치하여야 하기 때문에 유속측정시 효율성 떨어진다. 이에 홍수시 유량측정의 효율성을 증대시키고 전자파표면유속계의 활용도를 높이고자 편각측정이 가능하도록 전자파표면유속계의 성능을 개선하는 것이 본 연구의 주된 목적이다. 전자파표면 유속계에서의 편각 측정은 하천의 유속방향을 기준으로 정면에서 측정하면 수평 편각이 0도가 되며 좌우로 안테나를 회전하여 움직인 각도가 측정 편각으로 결정된다. 현장에서 전자파표면유속계의 사용시 편의성을 높이고 유량측정을 효율적으로 하기 위해서는 가급적 편각을 크게 해서 측정을 해야 하지만, 편각이 증가하면 전자파의 물리적 특성 때문에 반사된 신호의 수신 크기가 감소하여 측정이 불가능하게 된다. 이러한 문제를 해결하기 위해서는 유속 측정시 전자파 출력을 기존의 시스템보다 높게 물표면에 발사하여야 하며 안테나를 포함한 RF 모듈의 수신감도 및 지향성이 개선되어야 한다. 이에 편각측정이 가능하도록 이러한 사항에 주안점을 두어 새로운 시스템을 구성하였다. 수신감도 향상을 위해서는 물표면에 반사되어 돌아오는 신호를 가장 먼저 수신하는 안테나의 특성이 중요하며 그 다음 수신용 증폭기, IF 증폭기 순으로 개선이 필요하다. 본 연구에서는 안테나의 형태를 기존 파라볼릭 안테나에서 위상 배열 평면안테나로 변경하였으며, 이에 따른 이점으로는 송수신부를 분리하여 하나의 평면에 두 개의 안테나를 구성할 수 있다는 사항이다. 즉 외형적으로는 하나의 안테나로 보이지만 두 개의 안테나가 하나로 구성된 것이다. 송수신부를 분리하는 형태는 기존 파라볼릭 안테나에선 불가능한 구조로 변경에 따른 수신감도 향상은 수치적으로 10dB 이상 개선하였다. 송수신부 분리가 수신감도에 영향을 미치는 이유는 물표면으로 발사된 송신 신호의 일부가 수신단으로 유입되는 현상으로 누설되는 송신 신호를 최대한 차단하는 분리도가 수신 신호 검출에 직접적인 양향을 주기 때문에다. 평면 안테나를 적용하면 기존 파라볼릭 안테나에서 사용하던 써큘레이터라는 부품을 삭제할 수 있으며, 안테나의 구조적인 분리를 통해서 수신감도를 개선할 수 있었다. 안테나의 지향성은 발사하는 전자파의 빔폭 성능과 일치하며 각도 단위로 표시한다. 각도 값이 작을수록 전자파의 에너지가 한 곳에 집중된다고 말할 수 있다. 즉 빔폭이 크면 측정시 반사면적이 커져 정확한 지점의 유속을 측정하기 어려운 문제가 발생한다. 본 연구를 통해 빔폭은 기존 안테나 대비2도를 개선하였으며 25%의 개선 효과를 얻었다. 또한 수신감도 및 지향성 개선과 더불어 전자파의 출력을 기존 장비 대비하여 1.6배를 증가하여 편각측정을 위한 전자파표면 유속계의 성능을 개선하였다.