• Title/Summary/Keyword: 척

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Effect of Water-back-flushing in Advanced Water Treatment System by Tubular Alumina Ceramic Ultrafiltration Membrane (관형 알루미나 세라믹 한외여과막에 의한 고도정수처리 시스템에서 물 역세척의 영향)

  • Park, Jin-Yong;Lee, Song-Hui
    • Membrane Journal
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    • v.19 no.3
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    • pp.194-202
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    • 2009
  • In this study periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in advanced water treatment by tubular ceramic ultrafiltration membrane for Gongji stream in Chuncheon city. The back-flushing period (FT, filtration time) 2 min with periodic water-back-flushing of 15 sec showed the highest value of dimensionless permeate flux (permeate flux vs. initial permeate flux), and the lowest value of resistance of membrane fouling. Also in the results of BT effect at fixed FT 10 min, BT (back-flushing time) 20 sec showed the lowest value of resistance of membrane fouling and the highest value of dimensionless permeate flux, and we could be obtained the highest total permeate volume of 107.3 L. Consequently FT 10 min and BT 20 sec could be the optimal condition in Gongji stream water treatment, which was the exactly same results of our previous tubular alumina microfiltration. Then the average rejection rates of pollutants by our tubular ceramic UF system were 97.0% for turbidity, 32.1 % for chemical oxygen demand by manganese method, 28.8% for ammoniac nitrogen and 54.4% for T-P.

A Study on Position Detection in Gears in Automatic Production of Geared Shaft (기어의 생산자동화를 위한 기어의 위치정보 검출에 관한 연구)

  • Oh, Seok-Gyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.9
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    • pp.2223-2228
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    • 2014
  • Available shafts with gears at each end of the cylinder-shaped steel are widely used as power train components for automobiles. In order to automate the production of a geared shaft, there are problems to be solved. After one side of the cylinder is cut in gears, one of the problems is to determine the position of the cylinder which has been already cut. The shaft is then to be fed ahead with geared position to the chuck with jaws in geared shape. The other problem is to acquire information on an angular position of the shaft to fit to the jaws of the chuck. This paper deals with the magnetic detection sensor of gear position. Coils are installed in two places. Self-inductances of coils are detected by the changes of reluctance and are then compared. The magnetic analysis also has been carried out by the finite element analysis (FEM).

A Study on Economic Operation for Liner-Fleet by Fluctuation of Fuel Oil Price (연료유 가격변동에 따른 컨테이너선대의 경제적 운영방안)

  • Lee, Soo-Dong;Shin, Jeong-Hoon;Kim, Chul-Hyun;Chang, Myung-Hee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2009.06a
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    • pp.173-174
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    • 2009
  • For container shipping company, fuel oil prise is a considerable expense. In the last 3 years, fuel oil prises have risen considerably. An increasing fuel oil prise in container shipping, in the short term, is only partially compensated through surcharges and will therefore affect earnings negatively. This paper deals with the impact of increasing fuel oil price and capital costs for vessels on the number of vessels on the Asia-Europe trade. As per result of 'H' carrier's operation in 2008, there were no cost difference between 8 and 9 vessels operation in case the fuel oil price is USD 169/tons while adopt USD 31,818 as fixed cost. We can expect that the fuel oil price will not be decreased under USD 200 $/Ton on the basis of current high oil price phenomenon. When the fuel oil price is over USD 200 $/ton, therefore, 9 vessels operation is more economic than 8 vessel operation even if the fixed cost is over USD 35,000.

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Micellar Enhanced Ceramic Microfiltration for Removal of Aqueous Ferrous Ion: Effect of Surfactant Concentration and $N_2$-back-flushing (용존 철(II) 제거를 위한 미셀형성 세라믹 정밀여과: 계면활성제 농도 및 질소 역세척의 영향)

  • Park, Jin-Yong;Kang, Sung-Gyu
    • Membrane Journal
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    • v.19 no.2
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    • pp.136-144
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    • 2009
  • In this study, sodium dedocyl sulfate (SDS), which was anionic surfactant, was added for forming micelles to remove ferrous ions that could be contained with a small amount in industrial water. Then aggregates were formed by adsorption or binding of ferrous ions on the surface of micelles, and then rejected by ceramic membranes to remove ferrous ions. Ferrous concentration was fixed at 1mM and SDS was changed as $0{\sim}10mM$ to investigate the effect of the anionic surfactant. As a result, rejection rate of ferrous was the highest to 88.97% at 6mM. And we used ELS (Electrophoretic Light Scattering Spectrometer) to investigate particle size distribution of micellar aggregates depending on SDS concentration. Then distribution of large aggregates was the highest at 6mM. And we investigated effects of $N_2$-back-flushing time (BT) during periodic $N_2$-back-flushing on ceramic membranes. Finally optimal $N_2$-BT for NCMT-723l (pore size $0.10{\mu}m$) membrane was 20 sec.

Research on the validation of the Korean Version of the Ambivalence toward Men Inventory (한국판 남성에 대한 양가적 태도 척도 타당화 연구)

  • Kim, Eunha;Kim, Hyun Ji
    • Korean Journal of Culture and Social Issue
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    • v.26 no.4
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    • pp.525-549
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    • 2020
  • As the attitudes toward women is ambivalent (both hostile and ambivalent), people have a tendency to have ambivalent attitudes toward men. Despite conflicts between men and women caused by misogyny and misogyny have recently worsened in a Korean society, most of previous Korean studies have focused on the attitudes toward women. In addition, there has been no scale to measure such ambivalent attitudes toward men in Korea. Therefore, this study was designed to translate and validate the Ambivalence toward Men Inventory, a scale developed and currently utilized in the United State. Sample 1 (183 college students), sample 2 (300 college students), and sample 3 (317 adults) were used. Exploratory and confirmatory factor analyses resulted in 16 items and 2 factors. The tests of convergent and concurrent validity revealed strong evidence for the validity of the Korean version of the Ambivalence toward Men Inventory and the reliabilities of the two factors were .830~.917.

Development and validation of Everyday Gender Microaggression Scale (일상 속 성차별 경험 척도 개발 및 타당화)

  • Eunha Kim
    • Korean Journal of Culture and Social Issue
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    • v.24 no.4
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    • pp.593-614
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    • 2018
  • By applying the concept of microaggression (subtle and indirect form of discrimination), the aim of this study was to develop and validate the Everyday Gender Microaggression Scale (EGM). For this purpose, based on the results of literature review, surveys, and individual interviews, we developed 17 pilot items. Next, after expert content validation, we administered online survey to 180 adult women and conducted exploratory factor analysis. The result revealed 2 factors, 14 items, and this structure was reconfirmed through confirmatory factor analysis in another sample of 219 adult women. Convergent and concurrent validities were also examined via correlations with measures of sexism, depression, and life satisfaction. We discussed implications, ways to use the EGM, and suggestions for future research.

The Development and Validity of the Korean Wisdom Scale (한국판 지혜 척도의 개발 및 타당화 연구)

  • Sulim Lee ;Seong Ho Cho
    • Korean Journal of Culture and Social Issue
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    • v.18 no.1
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    • pp.1-26
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    • 2012
  • The purpose of this study was to develop the Korean Wisdom Scale and examine the validity of the scale. The Korean Wisdom Scale was developed and identified its validity by exploratory and confirmatory factor analysis, correlation analysis. The Korean Wisdom Scale consists of five factors, which are 'Outlook and Insight', 'Adjustment of Emotion', 'Perspective Taking', 'Integration of Experience', 'Concern and Comprehension'. Those five factors indicated the reasonable fit index by confirmatory factor analysis. In addition, this scale identified a significant positive relation with psychological well-being such as satisfaction and meaning of life, satisfaction of relationship. On the other hand, it indicated a negative relation with psychological symptoms such as neurosis and clinging. Also, the scale was differentiated from Adult Self-transcendence Inventory. Therefore, the results indicated that this scale has a reliable criterion-related validity. Finally, implication and limitation of this study were discussed in relation with future studies.

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Development of the Somatization Rating Scale (신체화 평가 척도의 개발)

  • Koh, Kyung-Bong;Park, Joong-Kyu
    • Korean Journal of Psychosomatic Medicine
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    • v.10 no.2
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    • pp.78-91
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    • 2002
  • Objective : The purpose of this study was to develop the somatization rating scale (SRS), and then to use the scale in clinical pracitice. Methods: First, a preliminary survey was conducted for 109 healthy adults to obtain 40 response items. Second, a preliminary questionnaire was completed by 215 healthy subjects. Third, a comparison was made regarding somatization responses among 242 patients (71 with anxiety disorder. 73 with depressive disorder, 47 with somatoform disorder, and 51 with psychosomatic disorder) and 215 healthy subjects. Results : Factor analysis yielded 5 subscales : cardiorespiratory and nervous responses, somatic sensitivity, gastrointestinal responses, general somatic responses, genitourinary, eye and muscular responses. Reliability was computed by administering the SRS to 62 healthy subjects during a 2-week interval. Test-retest reliability for 5 subscales and the total score was significantly high, ranging between .86-.94. Internal consistency was computed, and Cronbach's ${\alpha}$ for 5 subscales ranged between .72-.92, and .95 for the total score. Convergent validity was computed by correlating the 5 subscales and the total score with the total score of the global assessment of recent stress (GARS) scale, the perceived stress questionnaire (PSQ), and the symptom checklist-90-revised (SCL-90-R). The correlations were all at significant levels. Discriminant validity was computed by comparing the total score and the 5 subscale scores of the patient and control groups. Significant differences were found for 5 subscales and the total score. Only the depressive disorder group was siginificantly higher than control group in all the subscale scores and total scores of SRS among 4 patient groups. In somatic sensitivity, only depressive disorder patients were significantly higher than the normal controls, whereas in general somatic subscale, depressive disorder and somatoform disorder groups were significantly higher than the normal controls. In total scores of the SRS, female subjects were significantly higher than males. Conclusion : These results indicate that the SRS is highly reliable and valid, and that it can be utilized as an effective measure for research in stress- and somatization-related fields. The depressive disorder and somatoform disorder groups showed more widespread somatization than the anxiety and psychosomatic disorder groups.

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Recovery of Copper, Reuse of $TiO_2$, and Assessment of Acute Toxicity in the Photocatalytic Oxidation of Cu(II)-EDTA (Cu(II)-EDTA 광촉매 산화반응에서의 구리회수, $TiO_2$ 재사용 및 처리수 독성평가)

  • Yang, Jae-Kyu;Choi, Bong-Jong;Lee, Seung-Mok
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.8
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    • pp.844-851
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    • 2005
  • The purpose of this study was to determine feasibility of application of regenerated or recycled $TiO_2$ on the successive treatment of Cu(II)-EDTA. The recovery of copper, the reuse of $TiO_2$ and the assessment of acute toxicity was studied in the total eight successive photocatalytic reactions. Aqueous solution of $10^{-4}\;M$ Cu(II)-EDTA was treated using an illuminated $TiO_2$ at pH 6 in a circulating reactor. Two different procedures were applied in the reuse of $TiO_2$: i) recycle of $TiO_2$ without acid wash ii) regeneration of $TiO_2$ with acid wash to remove adsorbed copper in a previous experiment. The averaged decomplexation rate constant($k'_{obs}$) of Cu(II)-EDTA in recycle of $TiO_2$ without acid wash was approximately 45% less than that in regeneration of $TiO_2$ with acid wash. Removal of Cu(II) was near complete after 180 minutes in the total eight successive photocatalytic reactions using the regenerated $TiO_2$ after acid wash. In contrast, removal of Cu(II) was minimum at total fifth successive photocatalytic oxidation using the recycled $TiO_2$ without arid wash. The recovered $TiO_2$ was approximately 86% in average in each procedure. The recovered Cu(II) was 67.9% in average. The acute relative toxicity of the treated water rapidly declined at an initial reaction time up to 60 minutes but little declination was observed after 60 minutes due to little degradation of DOC. Relative toxicity of treated water using the recycled $TiO_2$ without acid wash we some what well correlated with the concentration of dissolved Cu(II). From this work, it is suggested that Cu(II)-EDTA can be effectively treated using an integrated cyclic photocatalytic oxidation with recovery of $TiO_2$ and Cu(II).

Primary Adenosquamous Carcinoma of the Stomach (위에서 발생한 선-편평세포암종)

  • Cho, Yong-Kwon;An, Ji-Yeong;Hong, Seong-Kweon;Choi, Min-Gew;Noh, Jae-Hyung;Sohn, Tae-Sung;Kim, Sung
    • Journal of Gastric Cancer
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    • v.6 no.1
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    • pp.31-35
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    • 2006
  • Purpose: A primary adenosquamous carcinoma of the stomach is relatively rare, accounting for only about 0.5% of all gastric cancers. However, its histopathologic characteristics are still unclear, and the most appropriate form of therapy has not been established yet. Materials and Methods: We retrospectively reviewed the clinicopathologic features of 8 patients with pathologically confirmed primary adenosquamous carcinomas out of 8,268 patients who underwent gastric cancer surgery at Samsung Medical Center between September 1994 and December 2004. Results: The median age of the 8 patients was 49 ($41{\sim}69$) years, and the male : female ratio was 5 : 3. In 3 patients, the tumor was located at the mid body of the stomach, and in 5 patients, at the lower body or antrum. The tumor sizes were $2.5{\sim}8cm$. Seven patients showed metastases to the regional lymph nodes. The UICC stage distribution were: 5 stage II, 2 stage III, and 1 stage IV. In the stage IV patient, a palliative gastrojejunostomy was performed, and he died 5 months after surgery. Of the 7 patients who underwent a radical gastrectomy and adjuvant chemotheratpy, the median survival was 34 ($12{\sim}66$) months, 2 patients died of cancer recurrence, and 4 patients are being followed up without evidence of recurrence. Conclusion: As for an adenocarcinoma of the stomach, a radical gastrectomy including regional lymph node dissection and postoperative adjuvant therapy should be performed for appropriate treatment of an adenosquamous carcinoma of the stomach.

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