• Title/Summary/Keyword: the 2000s

Search Result 14,905, Processing Time 0.044 seconds

Comparison of Sea Level Data from TOPEX/POSEIDON Altimeter and in-situ Tide Gauges in the East Asian Marginal Seas (동아시아 주변해역에서의 TOPEX/POSEIDON 고도 자료와 현장 해수면 자료의 비교)

  • Youn, Yong-Hoon;Kim, Ki-Hyun;Park, Young-Hyang;Oh, Im-Sang
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.5 no.4
    • /
    • pp.267-275
    • /
    • 2000
  • In an effort to assess the reliability of satellite altimeter system, we conducted a comparative analysis of sea level data that were collected using the TOPEX/POSEIDON (T/P) altimeter and the 10 tide gauge (TG) stations in the satellite passing track. The analysis was made using data sets collected from marginal sea regions surrounding the Korean Peninsula at T/P cycles of 2 to 230, which correspond to October 1992 to December 1998. Because of strong tidal activity in the study area, treatment of tidal errors is a very critical step in data processing. Hence in the computation of dynamic heights from the Tn data, we adapted the procedures of Park and Gamberoni (1995) to reduce errors associated with it. When these T/P data were treated, the alias periods of M$_2$, S$_2$, and K$_1$ constitutions were found at 62.1, 58.7, and 173 days. The compatibility of the T/P and TG data sets were examined at various filtering periods. The results indicate that the low-frequency signal of Tn data can be interpreted more safely with longer filtering periods (such as up to the maximum selected values of 200 days). When RMS errors for 200-day low-pass filter period was compared among the whole 10 tidal stations, the values spanned in the range of 2.8 to 6.7 cm. The results of correlation analysis at this filtering period also showed a strong agreement between the Tn and TG data sets over the whole stations investigated (e.g., P values consistently less than 0.0001). According to our analysis, we conclude that the analysis of surface sea level using satellite altimeter data can be made safely and reasonably long filtering periods such as 200 days.

  • PDF

An Analysis on the Characteristics of Each Phase's Risk Factors for High-Rise Development Project (초고층 개발사업 추진을 위한 단계별 리스크 요인의 특성 분석)

  • Chun, Young-Jun;Cho, Joo-Hyun
    • Korean Journal of Construction Engineering and Management
    • /
    • v.17 no.4
    • /
    • pp.103-115
    • /
    • 2016
  • The 106 buildings of 200 meters' height or greater were completed around the world in 2015 (CTBUH, The Council on Tall Buildings and Urban Habitat). They beat every previous year on record, including the previous record high of 99 completions in 2014. This brings the total number of 200-meter-plus buildings in the world to 1,040, exceeding 1,000 for the first time in history and marking a 392% increase from the year 2000, when only 265 existed. South Korea recorded three completions during 2015 - improving slightly over 2014, in which it had one. This study focused on the fact that high-rise building development project risks have not reduced in Korea in spite of numerous studies and measures. And it attempted to examine whether existing studies and measures have been presented on the basis of the accurate analysis of existing studies and measures and classify and analyze the characteristics of each phase' s risk factors in the hope that its results would be one reference point as to the measure to prevent high-rise building development project risks in the future. A high-rise building development project is the high risk project as compared with the low-rise project. Because a high-rise development project takes long and is very sensitive to the changing environment. Therefore, in order to succeed the project it becomes necessary to effectively manage the risk involved in the process of the high-rise building development project. The result of this study can be used as the guideline to make the risk management system for the high-rise development project.

The Effect of Algae on Coagulation and Filteration of Water Treatment Process (정수처리과정중 응집및 여과에 미치는 조류의 영향)

  • Lim, Young-Sung;Song, Won-Seb;Cho, Ju-Sik;Lee, Hong-Jae;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
    • /
    • v.19 no.1
    • /
    • pp.13-19
    • /
    • 2000
  • Seasonal variations of dominant algae species and the effects of these algae on coagulation and filteration of water treatment were investigated at Chilseo water treatment plant in downstream of Nakdong river from January in 1995 to Desember of 1998. The water quality of Nakdong river was found to be a hyper eutrophic state during the investigation periods. In the measurement, Chlorophyll-a contents ranged $20.7{\sim}180.9{\mu}g/l$ and total nitrogen contents(T-N) and total phosphorus contents(T-P) exceeded more than 3.4mg/l and 0.1mg/l, respectively. The changes in dominant algae species was in the order of Stepanodiscus sp., Asterionella sp., Melosira sp., Microcystis sp. and Synedra sp. from spring to winter. Microcystis sp. especially, was blooming during summer and Synedra sp. and Stepanodiscus sp. during winter. Although most diatomous algae appeared in the water treatment process caused filter clogging and reduced efficiency of coagulation and sedimentation, Synedra sp. and Stepanodiscus sp were revealed as the main trouble algae. Malfunction of water treatment process caused by Synedra sp. and Stepanodiscus sp. started at the algae concentrations of 800cells/ml and 1,820cells/ml, respectively. When chlorophyll-a content was $18.9{\mu}g/l$, the optimum amounts of coagulant were found to be 40mg/l of Alum and 16mg/l of PACS. Under condition of chlorophyll-a content of $154.1{\mu}g/l$, addition of Alum at the level of 75mg/l and PACS at the level of 35mg/l showed the lowest turibidity. The result indicates that increased amounts of the coagulants should be added for a better water treatment as chlorophyll-a contents increased. Addition of Alum at the amount of 60mg/l and 30mg/l of PACS removed Stepanodiscus sp. algae at the rate of 85% and 83%, respectively. In case of Synedra sp., 50mg/l of Alum and 25mg/l of PACS showed removal rates of 79% and 81%, respectively. Synedra sp. algae at the standing crops of 1,500cells/ml started filter clogging and a filtering process was completely inhibited after 8 hours. At this situation the filter clogging by Synedra sp. algae occurred at the depth of 5cm from the top anthracite layer. On the other, other algae did filter clogging at the depth of 10cm.

  • PDF

A Study for the development of the Korean orthodontic bracket (한국형 교정치료용 Bracket의 개발에 관한 연구)

  • Chang, Young-Il;Yang, Won-Sik;Nahm, Dong-Seok;Moon, Seong-cheol
    • The korean journal of orthodontics
    • /
    • v.30 no.5 s.82
    • /
    • pp.565-578
    • /
    • 2000
  • The aim of this study was development of the Straight-Wire Appliance(SWA) suitable lot the treatment or Korean. To accomplish the object of this study, Korean adult with normal occlusion were selected with following criteria : 1) no functional abnormality in the craniofacial area, 2) good dental arch form and posterior occlusal relationship, 3) Angle Class I occlusal relationship, 4) no experience of orthodontic, nor prosthodontic treatment, especially, no dental treatment on labial and buccal surfaces of teeth, 5) good racial profile. Impression were taken for upper and lower dental arches or the selected normal occlusion samples and the orthodontic dental stone models were fabricated. 5 well-trained orthodontists had examined the acquired dental stone models to select study samples which satisfy the Six keys to optimal occlusion of Andrews. 155 pairs of dental stone models (92 pairs of Male, 63 of Female) were finally selected. 3 dimensional digitization were performed with the Coordinate Measuring Machine(CMM, MPC802, WEGU-Messtechnik, Germany) and measuring of Angulation, Inclination, In-and-Out, Molar offset angle and Arch form were accomplished with a measuring software to achieve data for the development of SWA. Before the measurement, error study was performed on the 3 dimensional digitization with CMM, and the analysis of reliability of computerized measuring method adapted in this study and conventional manual method Presented by Andrews was performed. Results of this study were as to)lows : 1. Equi-distance digitization with mesh size 0.25 mm, 0.5 mm and 1.0 mm were acceptable in 3 dimensional digitization of dental stone model with the CMM, and the digitization with 1.0 mm mesh size was recommendable in terms of efficiency. 2. Computerized measuring method with 3 dimensional digitization was more reliable than manual measuring method of Andrews. 3. Data were collected for the development of SWA suitable for the morphological characteristics of Korean with the computerized measuring method with 3 dimensional digitization.

  • PDF

Relationship between Graft Appearance on Follow-up MRI and Knee Stability after Double Bundle ACL Reconstruction (이중 다발 전방십자 재건술 후 이식건의 자기공명영상 추시와 슬관절 안정성과의 관계)

  • Sim, Jae Ang;Kwak, Ji Hoon;Lee, Yong Seuk;Kim, Kwang Hui;Nam, Shin Woo;Jun, Sung Soo;Lee, Beom Koo
    • Journal of the Korean Arthroscopy Society
    • /
    • v.16 no.2
    • /
    • pp.128-133
    • /
    • 2012
  • Purpose: This study examined the relationship between graft appearance on follow-up magnetic resonance imaging (MRI) and knee stability after double bundle anterior cruciate ligament (ACL) reconstruction. Materials and Methods: For each patient, 1.5 tesla MRI's were obtained. The signal intensity of grafts was divided into 3 grades by Sononda's classification. The course of grafts was divided into two patterns: straight and curved. We assessed Lachman test, KT 2000 arthrometer and anterior drawer stress radiograph using Telos$^{(R)}$ in $30^{\circ}$ knee flexion for anterior stability and evaluated pivot shift test for rotatory stability. The correlation between graft appearance on MRI and the results of knee stability tests was evaluated. Results: The anteromedial (AM) graft was evaluated as being grade 1 in 66.7%, grade 2 in 26.7%, and grade 3 in 6.7% of the cases and the posterolateal (PL) graft was assessed as being grade 1 in 63.3%, grade 2 in 33.3%, and grade 3 in 3.3% of the cases according to the signal intensity. The AM graft was evaluated as being straight in 83.3% and curved in 16.7% of the cases, and the PL graft was assessed as being straight in 86.7% and curved in 13.3% of the cases according to the course. The course of AM graft was correlated with the results of anterior stability tests and the course of PL graft was correlated with the result of rotatory stability test. However, the signal intensity of grafts was not correlated with the results of anterior stability and rotatory stability tests. Conclusion: The course of AM is correlated with anterior stability and the course of PL is correlated with rotatory stability on follow-up MRI after double bundle ACL reconstruction.

  • PDF

Analysis of the Inter- and Intra-treatment Isocenter Deviations in Pelvic Radiotherapy With Small Bowel Displacement System (Small Bowel Displacement System을 이용한 골반부 방사선조사에서 치료간 및 치료중 중심점 위치변동에 관한 분석)

  • Kim Moon Kyung;Kim Dae Yong;Ahn Yong Chan;Huh Seung Jae;Lim Do Hun;Shin Kyung Hwan;Lee Kyu Chan
    • Radiation Oncology Journal
    • /
    • v.18 no.2
    • /
    • pp.114-119
    • /
    • 2000
  • Purpose : To evaluate the e지ent and frequency of the inter- and intra-treatment isocenter deviations of the whole pelvis radiation field in using small bowel displacement system (SBDS). Methods and Materials : Using electronic portal imaging device (EPID), 302 postero-anterior 232 lateral portal images were prospectively collected from 11 patients who received pelvic radiation therapy (7 with cervix cancer and 4 with rectal cancer). All patients were treated in prone position with SBDS under the lower abdomen. Five metallic fiducial markers were placed on the image detection unit for the recognition of the isocenter and magnification. After aligning the bony landmarks of the EPID images on those of the reference image, the deviations of the isocenter were measured in right-left (RL), cranio-caudal (CC), and PA directions. Results : The mean inter-treatment deviation of the isocenter in each RL, CC, and PA direction was 1.2 mm ($\pm$ 1.6 mm), 1.0 mm ($\pm$3.0 mm), and 0.9 mm ($\pm$4.4 mm), respectively. Inter-treatment isocenter deviations over 5 mm and 10 mm in RL, CC, and PA direction were 2, 12, 24$\%$, and 0, 0, 5$\%$, respectively. Maximal deviation was detected in PA direction, and was 11.5 mm. The mean intratreatment deviation of the isocenter in RL, CC, and PA direction was 0 mm ($\pm$0.9 mm), 0.1 mm ($\pm$ 1.9mm), and 0 mm ($\pm$1.6 mm), respectively. All intra-treatment isocenter deviations over 5 mm in each direction were 0, 1, 1$\pm$, respectively. Conclusions : As the greatest and the most frequent inter-treatment deviation of the isocenter was along the PA direction, it is recommended to put more generous safety margin toward the PA direction on the lateral fields if clinically acceptable in pelvic radiotherapy with SBDD.

  • PDF

A study on the degree of need of the knowledge of pathophysiology, clinical microbiology and mechanisms and effects of drugs in clinical nurses (기초간호자연과학의 병태생리학, 병원미생물, 약물의 기전과 효과 내용별 필요도에 대한 연구)

  • Choe, Myoung-Ae;Byun, Young-Soon;Seo, Young-Sook;Hwang, Ae-Ran;Kim, Hee-Seung;Hong, Hae-Sook;Park, Mi-Jung;Choi, S-Mi;Lee, Kyung-Sook;Seo, Wha-Sook;Shin, Gi-Soo
    • Journal of Korean Biological Nursing Science
    • /
    • v.2 no.1
    • /
    • pp.1-19
    • /
    • 2000
  • The purpose of this study was to define the content of the requisite knowledge of pathophysiology, clinical microbiology, and mechanisms and effects of drugs needed for clinical knowledge for nursing practice. Contents of knowlege on pathological physiology, clinical microbiology, and mechanisms and effects of drugs were constructed from syllabus of basic nursing subjects in 4 colleges of nursing, and textbooks. The degree of need of 72 items was measured with a 4 point scale. The subjects of this study were college-graduated 136 nurses from seven university hospital in Seoul and three in Chonnam Province, Kyungbook Province, and Inchon. They have been working at internal medicine ward, surgical ward, intensive care unit, obstetrics and gynecology ward, pediatrics ward, opthalmology ward, ear, nose, and throat ward, emergency room, rehabilitation ward, cancer ward, and hospice ward. The results were as follows : 1. The highest scored items of the knowledge of pathophysiology, clinical microbiology, and mechanisms and effects of drugs necessary for nursing practice were side effects of drugs, anticoagulants, mechanisms of drugs, antihypertensive drugs, tolerance and addiction of drugs, interactions among drugs, hospital infection in the order of importance. The lowest scored item was structure of microorganisms. 2. The highest order of need according to unit was repair in tissue injury unit, definition etiology classification of inflammation in inflammation unit, transplantation and immunologic response in alterations in immunity unit, thrombus and thrombosis in disorders of cardiovascular function unit, gene disorders in genetic disorders unit, hospital infection in infection unit, virus in microorganisms unit, side reactions of drugs in introduction unit, anticonvulsants in drugs for central nervous system unit, local anesthesia in anesthesia unit, anticoagulants in drugs for cardiovascular system unit, anti-inflammatory drugs in antibiotics unit, anti-ulcer drugs in drugs for digestive system unit, and bronchodilators in drugs for respiratory system unit. 3. The common content of the knowledge of pathophysiology, clinical microbiology, and mechanisms and effects of drugs needed for all clinical areas in nursing were side effects of drugs, anticoagulants, interactions among drugs, and hospital infection. However, the degree of need of each pathological physiology, clinical microbiology, clinical microbiology, and mechanisms and effects of drugs was different depending on clinical areas. 4. Significant differences in the knowledge of pathophysiology, clinical microbiology, and mechanisms and effects of drugs necessary for nursing practice such as tissue changes due to injurious stimuli, degenerative changes of tissue, alterations in metabolism of carbohydrates, ischemia, hyperemia and congestion, hospital infection, structure of microorganism, classification of microorganism, bacteria, virus, antidepressants, antipsychotic drugs, antiemetic drugs, antiparkinsonism drugs, antianxiety drugs, antibiotics, tuberculostatics, antiviral drugs, antifungal drugs, parasiticides, antiulcer drugs, antidiarrheais, and anti constipation drugs were shown according to the work area. 5. Significant differences in the knowledge of pathophysiology, clinical microbiology, and mechanisms and effects of drugs necessary for nursing practice such as transplantation and immunologic response, alterations in the metabolism of uric acid, structure of microorganism, classification of microorganism, immunosuppressants, drugs for congestive heart failure were demonstrated according to the duration of work. Based on these findings, all the 72 items constructed by Korean Academic Society of Basic Nursing science should be included as contents of the knowledge of pathophysiology, clinical microbiology, and mechanisms and effects of drugs.

  • PDF

A Study on the Interest in Menu and Food Purchase of Some Housemakers in Yosu, Chonnam Area (전남 여수시에 거주하는 일부 주부들의 식단작성의 관심도와 식품 구매에 관한 조사 연구)

  • Jung, Bok-Mi;Ahn, Chang-Bum
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.31 no.4
    • /
    • pp.703-712
    • /
    • 2002
  • This study was carried out to examine the interest in menu and food purchase of housewives living in Yosu, Chonnam. The survey was conducted by questionnaire including question about general characteristics of the subjects, meal planning and food purchase from October to November in 2000. The major general characteristics of subjects are summarized as follows: The forties was 39%, having a job was 44.5%, a high school education was 53.0%, and 1~2 million won in monthly household income was 50.1%. A couple with children was 75% and a 3~4 headed family was 57%. An apartment resident was 67% and one's own house was 67%. The higher the education level was, the higher the percentage of menu preparation and necessity was significantly (p<0.0001). On grocery purchase, the percent of planned purchase was higher than that of impulse purchase, which was higher in housewives without a job. The subject's favorite place for grocery purchase was a traditional market. The higher the age of subjects and the lower the education level of subjects were, the higher the grocery purchase at a traditional market was. However, the younger subjects and subjects with higher education level preferred to purchase groceries in a mart stores in an apartment, and supermarkets in order (p<0.0001). The factors to be considered during purchasing grocery were freshness of materials, price, nutrient, and taste in order. The results of this study showed that it is necessary to educate older person for importance of planning menu and encourage housewives with a job to plan grocery purchase to provide nutritionally adequate meals at reasonable coast.

The Effect of Long-term Application of Different Organic Material Sources on Chemical Properties of Upland Soil (유기물원이 다른 퇴비연용이 밭토양의 화학성 변화에 미치는 영향)

  • Kim, Jong-Gu;Lee, Kyeong-Bo;Lee, Sang-Bok;Lee, Deog-Bae;Kim, Seong-Jo
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.33 no.6
    • /
    • pp.416-431
    • /
    • 2000
  • The objective of this study was to determine the effects of various kinds of composts on the change of soil chemical properties in upland soils. Field experiments were conducted in the loam and sandy loam soils. Various kinds of composts such as poultry manure compost(PMC), cow manure compost(CMC), human excrement sludge(HES), and food industrial sludge compost(FISC) were applied annually at rates of 0, 40, and $80Mg\;ha^{-1}$ to soils grown with soybean and maize plants for 4 years during 1994 to 1997. The results of this study were as follows : The continuous application of human excrement sludge decreased soil pH up to 4.4~5.0, while other compost treatments increased soil pH compared with control plot. The EC increased initially and showed their maximum values at 20days after compost application, and then decreased up to 40 days, thereafter kept a certain level. The available phosphorous accumulated at 0~20cm depth in loam soil, and 0~50cm in sandy loam soil. Annual accumulation rates were 17% higher in sandy loam soil than loam soil. The more compost application rates and times, the higher base saturation percentage increased in upland soils. Four year's application at a rate of $80Mg\;ha^{-1}$ per year increased the base saturation percentage to 87~97% compared with 45% at control plot in the loam soil. While in sandy loam soil only three year's application of same rate increased the base saturation percentage to 81~92% compared with 30.4% at control plot. The average annual increasing rate of base saturation percentage at the same application rates of composts were higher in sandy loam soil by 2.0~3.7 times than in loam soil. The application of compost increased the exchangeable Ca, Mg, and K contents of soils by 2, 2~3, and 3~5 times, respectively, compared with the control. The contents of exchangeable cations were high in surface soil, and decreased with increase of soil depths. In the case of heavy metal content, there were no difference at the application of PMC and CMC but Ni, Fe, Zn, Cu was increased a little when the HES applied, and Ni and Cr was increased application with FISC.

  • PDF

THE EFFECTS OF SURFACE CONTAMINATION BY HEMOSTATIC AGENTS ON THE SHEAR BOND STRENGTH OF COMPOMER (지혈제 오염이 콤포머의 전단결합강도에 미치는 영향)

  • Heo, Jeong-Moo;Kwak, Ju-Seog;Lee, Hwang;Lee, Su-Jong;Im, Mi-Kyung
    • Restorative Dentistry and Endodontics
    • /
    • v.27 no.2
    • /
    • pp.150-157
    • /
    • 2002
  • One of the latest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not dry but left moist before application of the bonding primer Ideally the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically, contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during cavity preparation. The aim of this study was to evaluate the effect of contamination by hemostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were removed soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive papers on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows : Group 1: Dentin surface was not etched and not contaminated by hemostatic agents. Group 2: Dentin surface was not etched but was contaminated by Astringedent$^{\circledR}$(Ultradent product Inc., Utah, U.S.A.) Group 3: Dentin surface was not etched but was contaminated by Bosmin$^{\circledR}$(Jeil Pharm, Korea.). Group 4: Dentin surface was not etched but was contaminated by Epri-dent$^{\circledR}$(Epr Industries, NJ, U.S.A.). Group 5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6: Dentin sorface was etched and contaminated by Astringedent$^{\circledR}$. Group 7 : Dentin surface was etched and contaminated by Bosmin$^{\circledR}$. Group 8: Dentin surface was etched and contaminated by Epri-dent$^{\circledR}$. Group 9: Dentin surface was contaminated by Astringedent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 10: Dentin surface was contaminated by Bosmin$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 11 : Dentin surface was contaminated by Epri-dent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. After surface conditioning, F2000$^{\circledR}$ was applicated on the conditoned dentin surface The teeth were thermocycled in distilled water at 5$^{\circ}C$ and 55$^{\circ}C$ for 1,000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the knife-edge shearing rod of the Universal Testing Machine(Zwick Z020, Zwick Co., Germany) running at a cross head speed or 1.0 mm/min. Group 2 showed significant decrease in shear bond strength compared with group 1 and group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.