• Title/Summary/Keyword: problem analysis

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An Analysis of STS Contents in the High School Chemistry(II) Textbook (화학II 교과서의 STS 내용 분석)

  • Kim, Jung-Tae;Kim, Yun-Hi;Moon, Seong-Bae
    • Journal of the Korean Chemical Society
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    • v.46 no.1
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    • pp.90-96
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    • 2002
  • The STS contents, emphasized in the 6th curriculum, in the chemistry textbooks(II) were analyzed. The STS contents in textbooks showed average value of 2.7%. The chapter of ‘chemical bond and compound' were included 3.8% of STS contents. And the chapter of ‘atomic structure and periodic table', ‘state of material and solution', ‘science of material', and ‘chemical reaction' contained 3.2%, 2.2%, 1.9%, and 1.9% of STS contents, respectively. When the STS contents were analyzed by STS topics of Piel, the results are as follows; 33.7% on effect of technological developments, 27.5% on environmental quality and utilization of natural source, 19.6% on human engineering, 13.8% on energy, and 5.4% on sociality of science. However, there were no topics on population, space research and national defense. When the STS contents were analyzed by student activities of SATIS, most of the activities were research and case study. There were few field activities of practical investigation, problem solving and decision making, research design and stimulation. There were no activities of role play.

A Study on the Evaluation of Economic Benefit for Port Hinterland's Investment in Busan New Port (부산항 신항 켄테이너터미널 배후단지 조성사업의 경제성 평가에 관한 연구)

  • Lee, Gi-Hwan;Hwang, Du-Geon;Kim, Myeong-Hui
    • Journal of Korea Port Economic Association
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    • v.24 no.4
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    • pp.153-171
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    • 2008
  • The purpose of this paper is to estimate economic benefits for the investment of port hinterland. This research has conducted the empirical analysis, by calculating the investment of port hinterland. The key factor for the economic benefits for the hinterland is the utilizing throughputs. This demand is influenced by the throughput in the port. However the data is different between the different organizations. The positive opinions are prevailed about constructing of port hinterland by a optimistic view about throughput. However this paper analyzes the economic benefits by a pessimistic point of view. The main results of this paper are as follows: First, the port hinterland of Busan New Port does not have economic benefit for investment and the hinterland will face the overcapacity problem. We recommend that the plan for investment has to be considered the modification. Second, data of forecasted throughputs is an important factor for evaluation of hinterland's investment. The research for reliable forecasting of throughput has to be preceded for the pertinent evaluation of hinterland's investment.

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Baleen Whale Sound Synthesis using a Modified Spectral Modeling (수정된 스펙트럴 모델링을 이용한 수염고래 소리 합성)

  • Jun, Hee-Sung;Dhar, Pranab K.;Kim, Cheol-Hong;Kim, Jong-Myon
    • The KIPS Transactions:PartB
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    • v.17B no.1
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    • pp.69-78
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    • 2010
  • Spectral modeling synthesis (SMS) has been used as a powerful tool for musical sound modeling. This technique considers a sound as a combination of a deterministic plus a stochastic component. The deterministic component is represented by the series of sinusoids that are described by amplitude, frequency, and phase functions and the stochastic component is represented by a series of magnitude spectrum envelopes that functions as a time varying filter excited by white noise. These representations make it possible for a synthesized sound to attain all the perceptual characteristics of the original sound. However, sometimes considerable phase variations occur in the deterministic component by using the conventional SMS for the complex sound such as whale sounds when the partial frequencies in successive frames differ. This is because it utilizes the calculated phase to synthesize deterministic component of the sound. As a result, it does not provide a good spectrum matching between original and synthesized spectrum in higher frequency region. To overcome this problem, we propose a modified SMS that provides good spectrum matching of original and synthesized sound by calculating complex residual spectrum in frequency domain and utilizing original phase information to synthesize the deterministic component of the sound. Analysis and simulation results for synthesizing whale sounds suggest that the proposed method is comparable to the conventional SMS in both time and frequency domain. However, the proposed method outperforms the SMS in better spectrum matching.

Concrete Mixture Design for RC Structures under Carbonation - Application of Genetic Algorithm Technique to Mixture Conditions (탄산화에 노출된 콘크리트 구조물의 배합설계에 대한 연구 - 유전자 알고리즘 적용성 평가)

  • Lee, Sung-Chil;Maria, Q. Feng;Kwon, Sung-Jun
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.335-343
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    • 2010
  • Steel corrosion in reinforced concrete (RC) structures is a critical problem to structural safety and many researches are being actively conducted on developing methods to maintain the required performance of the RC structures during their intended service lives. In this study, concrete mixture proportioning technique through genetic algorithm (GA) for RC structures under carbonation, which is considered to be serious in underground site and big cities, is investigated. For this, mixture proportions and diffusion coefficients of $CO_2$ from the previous researches were analyzed and fitness function for $CO_2$ diffusion coefficient was derived through regression analysis. This function based on the 12 experimental results consisted of 5 variables including water-cement ratio (W/C), cement content, sand percentage, coarse aggregate content per unit volume of concrete in unit, and relative humidity. Through genetic algorithm (GA) technique, simulated mixture proportions were proposed for 3 cases of verification and they showed reasonable results with less than relative error of 10%. Finally, assuming intended service life, different exposure conditions, design parameters, intended $CO_2$ diffusion coefficients, and cement contents were determined and related mixture proportions were simulated. This proposed technique is capable of suggesting reasonable mix proportions and can be modified based on experimental data which consider various mixing components like mineral admixtures.

An Experimental Study on Mechanical Properties of Ultra-High Strength Powder Concrete (압축강도 300MPa 이상의 초고강도 분체콘크리트 개발을 위한 실험적 연구)

  • Jo, Byung-Wan;Yoon, Kwang-Won;Park, Jung-Hoon;Kim, Heoun
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.287-295
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    • 2010
  • In this study, ordinary Portland cement was used and the air void was minimized by using minute quartz as the filler. In addition, steel fibers were used to mitigate the brittle failure problem associated with high strength concrete. This study is in progress to make an Ultra-high strength powdered concrete (UHSPC) which has compressive strength over 300 MPa. To increase the strength of concrete, we have compared and analyzed the compressive strengths of the concretes with different mix proportions and curing conditions by selecting quartz sand, dolomite, bauxite, ferro silicon which have diameters less than 0.6 mm and can increase the bond strength of the transition zone. Ultra-high strength powdered concrete, which is different from conventional concrete, is highly influenced by the materials in the mix. In the study, the highest compressive strength of the powdered concrete was obtained when it is prepared with ferro silicon, followed in order by Bauxite, Dolomite, and Quartz sand. The amount of ferro silicon, when the highest strength was obtained, was 110%, of the weight of the cement. SEM analysis of the UHSPC showed that significant formation of C-S-H and Tobermorite due to high temperature and pressure curing. Production of Ultrahigh strength powdered concrete which has 28-day compressive strength upto 341MPa has been successfully achieved by the following factors; steel fiber reinforcement, fine particled aggregates, and the filling powder to minimize the void space, and the reactive materials.

Maintenance Management System for Urban Drainage System (도시유역 내배수시설 유지관리시스템)

  • Lee, Jung-Ho;Joo, Jin-Gul;Kim, Eung-Seok;Park, Moo-Jong;Kim, Joong-Hoon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.5
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    • pp.119-128
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    • 2008
  • Sewer rehabilitation is performed to improve the problem for urban drainage sewer system recently. However the data for the sewer system is not stored enough so that the sewer system is difficult to be managed systematically. In this study, a maintenance management system for urban drainage system is developed to store the data efficiently and manage the system systematically. In the developed system, a hydraulic and hydrologic analysis module is included to test the carrying capacity of a sewer pipe and estimate the amount of combined sewer overflows. The I/I and superannuation evaluation module is included in this system. The module distribute the total inflow/infiltration observed at the several sampling points in a drainage area to the individual pipes of the entire sewer system. Then the superannuation of a sewer pipe is evaluated according to the amount of I/I of the pipe. And in the developed system, the optimal rehabilitation priority module is included to determine the optimal priority and support the decision making for the sewer rehabilitation. The maintenance management system which is developed in this study is constructed by the association with the developed modules and the system is formed as graphical user interface system.

A Development of Career Aptitude Scale for Design Majoring University Students (디자인 진로적성검사의 개발)

  • Gil, Im-Joo;Yang, Sung-Yong
    • Archives of design research
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    • v.19 no.1 s.63
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    • pp.283-292
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    • 2006
  • This study developed 'Design Career Aptitude Scale' to help design majoring college students who are seeking their career goals or conflicting to decide their majors. The subscales of the 'Design Career Aptitude Scale' are 'basic job competency', 'basic design competency' and' advanced design competency'. This study further classified the 'basic job competency' and 'basic design competency' into several subareas and defined each concepts. Based upon the classification of each subareas, tentative test items were developed through the verification of validity three times by seven design professionals. A pilot study of the developed scale was administered to 506 design majoring college students. The results by exploratory factor analysis were that the basic job competency was composed of four factors; ability of interpersonal relations, goal-driven ability, problem solving ability and self-developing ability. The basic design competency was composed of five factor, grounding in design, computer skills, material sensitivity, formative ability and color sensitivity. The results can be seen as an adequate, delicate factor structure to represent design aptitude, and also the scale can be a useful tool to the students who are conflicting to decide their majors and careers. The further study needed to validate the scale through the investigation of the relationship with related scales measuring designing ability, and with other criteria-referenced group.

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A Case Study on the Boring-Hole Blasting for Offering of the Ground Vibration Source (지진동 Source 제공을 위한 심부 시추공발파 기술사례)

  • 조영곤;김희도;조준호
    • Tunnel and Underground Space
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    • v.13 no.3
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    • pp.187-195
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    • 2003
  • This case study which is to make 2-Dimension earth's crust structures clearly is about the great boring-hole blasting to provide ground vibration source of the reflected wave research on the Korean Peninsula earth's crust structures research. For this study we've done blasting twice-500 ㎏/charge per delay, 1,000 ㎏/charge per delay, and the specifications of blasting are the following - dia.: 300 ㎜, boring-depth : 100m, besides, we used the explosives and electric detonators which have sufficient detonating velocity and very excellent safety, capacity of detonating, accurate delay time. We charged explosives into steel pipe with bulk type to avoid dead pressure by ground water. And then we tested about pipe airtight and blasting to certificate which has no problem by using on this study. In the results, we succeeded each blasting in Seosan, Youngdong. For the Peak Sum Vector(PSV) around the blasting at the main points, its real measured PSV is higher 180 % than estimated PSV with USBM. In this study we can't to be analysis of vibration velocity, but to be key providing vibration source.

THE EFFECT OF GROWTH FACTORS IN PLATELET-RICH PLASMA ON THE ACTIVITY OF OSTEOBLAST CELL LINE (혈소판농축혈장 내의 성장요소가 조골세포주의 활성도에 미치는 영향)

  • Jung Tae-Wook;Kim Yung-Soo;Kim Chang-Whe;Jang Kyung-Soo;Lim Young-Jun
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.2
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    • pp.175-191
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    • 2004
  • Statement of problem: Platelet-rich plasma(PRP) is well known to be very effective method to stimulate and accelerate the healing of bone and soft tissue. However, there are few reports which deal with the mechanisms of the PRP on the activation of the osteoblasts. Purpose: This study was aimed to investigate the effect of growth factors in PRP on the activity of osteoblasts. Material and method: To evaluate the effect on human, human osteoblast cell line was cultured. PRP was extracted from the blood of a healthy volunteer. Using the recombinant growth factors of PDGF, $TGFT-\beta$, IGF-1, bFGF which are mainly found at bone matrix and their neutralizing antibody, the effect of PRP on the attachment and proliferation of osteoblasts was evaluated. To evaluate the autocrine and paracrine effects, conditioned media(CM) of PRP was made and compared with PRP. By the western blot analysis, the expression of growth factors in PRP, CM was examined. Cell morphology was compared by the light microscope. Results : 1) The effects of CM on osteoblast were similar to the effects of PRP. 2) PRP, CM, recombinant $TGF-\beta$, bFGF, IGF-1 showed significantly higher cellular attachment than control(p<0.05) in the cell attachment assay. In the cell proliferation assay, PRP, CM, recombinant $TGF-\beta$, IGF-1, bFGF, PDGF increased significantly cell proliferation(p<0.01). Among the recombinant growth factors, IGF-1 showed the highest cellular attachment and proliferation. 3) In the western blot assay, bFGF, IGF-1, PDGF weve equally expressed in PRP and CM. 4) The attachment of osteoblast cell decreased significantly after the addition of neutralizing antibody against $TGF-\beta$, IGF-1(p<0.05). In the cell proliferation assay, the addition of neutralizing antibody against $TGF-\beta$, bFGF, PDGF, IGF-1 decreased significantly the cellular proliferation(p<0.05). The amount of decreasing in the cell attachment and proliferation is the highest in at-lGF-1. 5) The cells in control group were flattened and elongated with a few cellular processes in the a light microscope. But, the cells appeared as spherical, plump cells with well developed cellular processes in experimental groups. The cells in PRP and CM had more prominent developed features than recombinant growth factor groups. Conclusions : These findings imply that PRP maximize the cellular activity in early healing period using the synergistic effect, autocrine, paracrine effects of growth factors and increase the rate and degree of bone formation.

The Hope of the Stroke Patients (뇌졸중환자의 희망)

  • 김이순
    • Journal of Korean Academy of Nursing
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    • v.27 no.1
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    • pp.212-227
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    • 1997
  • Cerebrovascular diseases in Korea is an important health problem since mortality and mobidity have been increased rapidly. It marked the 2nd cause of specific death rates in 1993. The stroke causes physical function disorder due to hemiparalysis and emotional disorder, and stroke patients experience helplessness, powerlessness. sense of alienation and loss of hope. These feelings make the rehabilitation difficult because they lose the will of life. The subjects of the study were seven citizens who live in Pusan, are over 50 years old and belong to low income-level. The data were collected from Jan. to Sep. 1995. The researcher as a caregiver and volunteer made confidence of them and asked for their agreement on the purpose of the study. The subjects expressed their experience as openheartedly as possible. The analysis of the data was made through the phenomenological analytic method suggested by Giorgi, which is as follows ; as an unit of description which include the subject' expressions and the researcher's observation, it is examined the theme that express the hope experience with the subject's language(underlining), and the focal meanings are identified. The focal meaning is the crystalization of the theme, which is written in the language of the researcher. After intergrating the focal meaning and make the situated structural description as the meaning of the hope experience identified on each subject's point. After intergrating the situated structural description and make the general structural description as the meaning of the hope experience identified on total subject's point then the systemizing of the structure of the hope experienced phenomena and the flowing of the conciousness was researched. The conclusions of this study was as follows : The ten sources of hope which the subjects experienced were sorted as under 〈mutual relations to others : spouse, children, relatives, fellow believer. health professioner. associate patient group〉, 〈spiritual dependence〉. 〈recovery of physical function〉. 〈rumination of the past life〉, 〈expectation of the future〉. 〈economic power〉, 〈belief〉, 〈ability〉. 〈spontaneous participation〉 and 〈recovery of roles〉. Their hope was spoken out by the following two kinds of linguistics. First. the hope was expressed in the affirmative expression as follows : 〈 to be dependable〉, 〈to make efforts〉, 〈to keep under control〉, 〈to desire〉, 〈to be pleasant〉, 〈to be peaceful〉, 〈to be grateful〉, 〈to give help〉, 〈self-confidence. Courage〉, 〈to be happy〉, 〈to satisfy oneself〉, 〈to share with others〉, 〈to understand〉 and 〈to be affected, be impressed〉 Second, the hope was expressed in the negative on pression as under : 〈to be distressed〉, 〈to be uneasy〉, 〈to be sorry, be unsatisfied〉 〈despair〉, 〈to abandon〉, 〈to be fearful〉, 〈to suffer〉, 〈to bear a burden〉 〈to be confused〉, 〈to be solitary〉, 〈chest trouble〉, 〈to feel heavy〉 〈grief〉, 〈to be daunted〉, 〈to get angry〉, 〈to be uncomfortable〉, 〈to have something regretable〉 and 〈to feel guilty〉. And their hope was expressed by the following four behavioral expressions : 〈physical sphere〉, 〈psychological sphere〉, 〈social support sphere〉 and 〈spiritual sphere〉. The reaction patterns of their hope experience appeared in the following 4 coping method : 〈conquest type〉, 〈dependence type〉, 〈adaptation type〉 and 〈fate type〉. Finally, in the hope structure the sense of certainty don't always coexict with the sense of uncertainty, When the stroke patients try to search for the best quality of life, the senses of certainty and uncertainty make a continual cyclic system in the hope structure.

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