• Title/Summary/Keyword: condition rating

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A Study on Improvement of Maintenance Strategy based on Analysis of Bridge Safety Grade (교량 안전등급 분석을 통한 유지관리전략 개선 방안 연구)

  • Hwang, Yoon-Koog;Sun, Jong-Wan;Choi, Young-Min;Park, Kyung-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.36-43
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    • 2021
  • Because bridges are major national infrastructure, regular safety inspections or diagnoses for bridges have been conducted in accordance with the "Special Act on the Safety and Maintenance of Facilities." Accordingly, the condition and safety assessments of the bridge are conducted to derive the condition and safety rating, respectively. A lower result is determined to be the safety grade of the bridge. In this study, the relationship between the condition rating and safety rating, which are the core of the bridge safety grade, was analyzed by the representative superstructure types of bridges, such as RC slab, PSCI girder, Steel box girder, Rhamen, and Preflex girder, to identify the correlation status and range between each rating. A reasonable improvement direction for establishing existing maintenance policies was suggested by proposing an alternative plan to change the proper implementation cycle of the inspection and diagnosis of bridge superstructure types. As a result of the research, it is necessary to adjust the inspection and diagnosis cycle according to the superstructure type and safety grade. In addition, maintenance policies need to be improved through detailed research on more diverse bridge types in the future.

A Study on the Stabitity and Dyeing Condition in the Curcuma Longa L. (울금의 색소 추출과 안정성에 관한 연구)

  • 소황옥
    • Journal of the Korean Society of Costume
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    • v.39
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    • pp.79-89
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    • 1998
  • This study was carried out the effect of stability and color extract for it's condition in the curcuma L.. dyeing. The stability is to investigate the absorbance of the curcumin, one of the major yellow pigments and the stability regarding the effect of light, oxygen temperature and pH. The dyeing condition is compared the effect of mordanting condition and the best way to extract pigment and analysed through the color-fastness rating, color-difference value test. The main results obtained are summarized as follows ; 1.The best and proper solvent to extrect curcumin pigment was a ethanol and a distilled water. 2. The light effect indicated that the absorbances of solution in absence of ligh was more stable. 3. The oxygen(O2) effect to curcumin show-ed that the condition in the absence of O2 was more stable than that in presence of O2 4. The temperature showed that the absorbnace was best stable in4$^{\circ}C$ and less changed at $25^{\circ}C$ 5. The curcumin-etanol solution was stable in pH 2~4. 6. Generally color-fastness rating to silk, wool and cotton indicated that crocking C.F. and perspiration C.F. were more than 3rd grade and dry cleaning C.F. was more than 4th grade. But light color-fastness and washing color-fastness were very poor. 7. To make good color fastness, the mordan-ting treated group and the pre-mordant conditions were more effective than others 8. When compared with color-difference value test indicated that the silk was looks like more reddish and bluish color and than the wool and cotton were greenish and bluish. As a mordant, A(C2H4OH(COOH3) and D(K2Cr2O7)were more effective to make green-ish color in the silk and the reddish color was abtained by B(Al.K(SO4)2.12H2O) and C(FeSO4.7H2O).

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Development of Control Algorithm and Detection of the Small Leakage Current (미소 누전전류 검출 및 차단제어기 설계)

  • 반기종;김낙교
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.3
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    • pp.161-165
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    • 2004
  • In this paper, we have designed the ground faults detection and interrupting controller at normal condition of AC 120v to 240v rating voltage. Ground faults in electrical network have the characteristics of low current, 60㎐ frequency to 2㎑frequency. The load condition are no load and 20A load. The trip level of the controller is 6㎃ with ground faults. The Controller algorithm is implemented using pic16c71 microprocessor.

Premenstrual Changes in Adolescents (청소년의 월경전기 변화)

  • Joe, Sook-Haeng
    • Korean Journal of Psychosomatic Medicine
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    • v.4 no.2
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    • pp.198-206
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    • 1996
  • To assess premenstrual changes in adolescents, a self rating retrospective premenstrual assessment from(PAF) and a prospective daily rating form(DRF) were administered to 230 high school students who reported premenstrual changes. The results were as follows 1) According to typological categories of retrospective premenstrual assessment form, the most commonly reported changes in mood and behavior were major depressive syndrome(40.0%), impulsive syndrome(20.9%). Especially among the subtype of depressive syndrome, hostility feature and withdrawal feature were most frequent. The most commonly reported changes in physical condition were general discomfort(73.5%), fatigue(33.9%). 50.9% of all subjects reported impaired social function. 2) 41.2% of the subjects who met the criteria for typological categories of retrospective premenstrual assessment form were confirmed by prospective daily rating form. 3) According to different criteria of percent change method of assessing symptom change, 38.7% of all subjects had at least one mild premenstrual change and 23.5% had at least one moderate premenstrual change. 4) Using prospective daily rating form, overall psychological changes were confirmed more frequently than physical changes. Of the mild premenstrual changes, 'low energy, tired & weak', 'less or impaired work' were most common changes. Of the moderate premenstrual changes, the most common change was 'low energy, tired & weak'. 5) As attitude toward menstruation, 44.9% of the subjects with confirmed premenstrual changes had more negative attitude(disgusted) toward menstruation. 6) The subjects with confirmed mild or moderate premenstrual changes had only dysphoric mood changes or both physical and dysphoric mood changes, but did not have only physical changes. These results suggest that retrospective reports of premenstrual changes were partially confirmed by daily prospective ratings. A substantial number of adolescents appeared to experience premenstrual changes, and the most common confimed premenstrual change of mild or moderate severity was 'low energy, tired and weak'.

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Developing an Estimation Model for Safety Rating of Road Bridges Using Rule-based Classification Method (규칙 기반 분류 기법을 활용한 도로교량 안전등급 추정 모델 개발)

  • Chung, Sehwan;Lim, Soram;Chi, Seokho
    • Journal of KIBIM
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    • v.6 no.2
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    • pp.29-38
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    • 2016
  • Road bridges are deteriorating gradually, and it is forecasted that the number of road bridges aging over 30 years will increase by more than 3 times of the current number. To maintain road bridges in a safe condition, current safety conditions of the bridges must be estimated for repair or reinforcement. However, budget and professional manpower required to perform in-depth inspections of road bridges are limited. This study proposes an estimation model for safety rating of road bridges by analyzing the data from Facility Management System (FMS) and Yearbook of Road Bridges and Tunnel. These data include basic specifications, year of completion, traffic, safety rating, and others. The distribution of safety rating was imbalanced, indicating 91% of road bridges have safety ratings of A or B. To improve classification performance, five safety ratings were integrated into two classes of G (good, A and B) and P (poor ratings under C). This rearrangement was set because facilities with ratings under C are required to be repaired or reinforced to recover their original functionality. 70% of the original data were used as training data, while the other 30% were used for validation. Data of class P in the training data were oversampled by 3 times, and Repeated Incremental Pruning to Produce Error Reduction (RIPPER) algorithm was used to develop the estimation model. The results of estimation model showed overall accuracy of 84.8%, true positive rate of 67.3%, and 29 classification rule. Year of completion was identified as the most critical factor on affecting lower safety ratings of bridges.

A Review Method of Calculation Results on Cable Ampacity using the Transformation to Electric Equivalent Circuit from Cable Thermal Circuit (케이블 열회로의 전기적 등가회로 변환을 이용한 케이블 허용전류 검토 방법)

  • Kang, Yeon-Woog;Kim, Min-Ju;Jang, Tae-In;Park, Jin-Woo;Park, Hung-Sok;Kang, JI-Won
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.5
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    • pp.738-744
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    • 2016
  • Current rating of a power cable can be calculated by the maximum allowable temperature in an insulating material considering the heat transfer from cable conductor. Therefore, it is very important to calculate the current rating using electrical equivalent circuit by calculated cable thermal circuit parameters but, it has not been fully investigated yet. In this paper, in order to determine the current rating of power cable, conventional calculation method has been reviewed considering the conductor resistance, loss factor of sheath, dielectric losses and thermal resistances based on the maximum allowable temperature of 345 kV $2500mm^2$ XLPE cable. To confirm the calculation result of the current rating, the conductor temperature should be examined whether it reaches the maximum allowable temperature by the thermal equivalent circuit of the cable. Then, utilizing EMTP (Electro-Magnetic Transient Program) which is a conventional program for electrical circuit, the thermal equivalent circuit was transformed to an electric equivalent circuit using an analogous relationship between thermal circuit and electrical circuit, and temperature condition including cable conductor, sheath, cable jacket could be calculated by the current rating of 345 kV $2500mm^2$ XLPE cable.

An Analysis on the Stage-Discharge Relation Curve with the Temporal Variation of the River Bed -at Indogyo Station of the Han River- (하상(河床) 경년변화(經年變化)에 따른 수위(水位)-유량(流量) 관계곡선(關係曲線)의 해석(解析) -한강(漢江) 인도교지점(人道橋地點)을 중심(中心)으로-)

  • Cheong, Heung Soo;Lee, Won Hwan;Lee, Jae Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.3
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    • pp.61-71
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    • 1988
  • The stage-discharge relation curve(rating curve) is the basic formula in hydrologic analysis. It plays an important role in converting to the discharge from available flood water level data including the daily mean stage. However, the river induces a cross section change at the gauging station because of the composed material of the river bed and three processes of the stream flow; i.e., erosion, transportation, and sedimentation. Rating curve has to be revised according to the temporal variation of the river bed due to the those factors. In this study, the basic rating curve is developed with respect to the current river bed to convert the existing rating curves and also to seize the hydraulic and geometric characteristics for the temporal variation of the river bed, relationships among the basic rating curve and the existing rating curves, water level, cross sectional area, and flow velocity are analyzed. Indogyo station, which is not only the key station of the Han river but also greatly changed the river bed after completion of the Han river development plan during the year 1983 to 1986, was chosen for the study. In this study, the river bed is assumed in a dynamic equilibrium condition. The basic rating curve is developed using hydrologic data of the physical year of 1987. For a given discharge, relationships for conversion of previous data, stage and velocity, the current one are formulated. To verify the usefulness of the relationships, stage-cross sectional area and stage velocity formula are also derived. Both hydrologic method using continuity equation and statistical method by the rating curve are compared and checked, then the validation of the both are positively shown.

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A Case of Chronic Nummular Dermatitis Improved by Hwangryunagyo-tang (황련아교탕(黃連阿膠湯) 투여로 호전된 만성 동전 모양 습진 1례)

  • Ju-Hyun Lee;Sang-Bae Lee;Eun-Heui Jo;Min-Cheol Park
    • The Journal of Korean Medicine
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    • v.45 no.1
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    • pp.215-224
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    • 2024
  • Objectives: This study aims to report a case of chronic nummular dermatitis improved by Hwangryunagyo-tang. Methods: The patient in this study was a 15-year-old female, who visited our hospital with symptoms such as redness, erythema, papule, excoriation, scale, exudation, crusting, lichenification, and pruritus of the extremities and trunk. Considering that the skin lesions were coin-shaped and persisted for more than 6 months, the patient's symptoms were diagnosed as chronic nummular eczema. Based on the patient's symptoms and overall condition, Hwangryunagyo-tang was prescribed. Results: Approximately 4 months after administration of Hwangryunagyo-tang, the exudate disappeared, and overall skin symptoms improved, from objective score 33.7 to 6.6, leaving only slight scale, dryness, and pigmentation. As the pruritus of the skin lesion decreased from numeric rating scale 8 to 1, the patient's sleeping condition also improved from numeric rating scale 9 to 0. Conclusion: This study is significant in that the symptoms of chronic nummular dermatitis were effectively improved after administration of Hwangryunagyo-tang.

Risk Assesment for Large-scale Slopes Using Multiple Regression Analysis (다중회귀분석을 이용한 대규모 비탈면의 위험도 평가)

  • Lee, Jong-Gun;Chang, Buhm-Soo;Kim, Yong-Soo;Suk, Jae-Wook;Moon, Joon-Shik
    • Journal of the Korean Geotechnical Society
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    • v.29 no.11
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    • pp.99-106
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    • 2013
  • In this study, the correlation of evaluation items and safety rating for 104 of large-scale slopes along the general national road was analyzed. And, we proposed the regression model to predict the safety rating using the multiple regressions analysis. As the result, it is shown that the evaluation items of slope angle, rainfall and groundwater have a low correlation with safety rating. Also, the regression model suggested by multiple regression analysis shows high predictive value, and it would be possible to apply if the evaluation items of excavation condition and groundwater (rainfall) are not clear.

A Study on Performance of Current Transformer in High Voltage System (고압계통 변류기 동작 특성 검토)

  • Choi, Ki-Yeol;Lee, Duck-Soo;Park, Moon-Bin;Kim, Hee-Taek;Chang, Ki-Poong
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.5-7
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    • 2006
  • Current transformers(CTs) whose rating is selected per a full load current of a feeder in high voltage system can be easily saturated due to high fault current that may be several hundred times of the full load current of the feeder. However, the protective relay shall operate properly at the fault without mis-operation under the CT saturation. So, in selecting the CT rating, it is necessary to consider the behaviour of CT and a performance of protection scheme in condition where CT can be saturated. In this paper, a performance of CT and a degree of saturation are studied and verified whether its ratings are proper for the operation of the protective relay.

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