• 에너지공학
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• 제26권4호
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• pp.45-56
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• 2017

Coal power plants produce electricity for the nation's power grid, but they also produce more hazardous air emissions than any other industrial pollution sources. The quantity is staggering, over 386,000 tons of 84 separate hazardous air pollutants spew from over 400 plants in 46 states. In South Korea also, annual coal ash generation from coal-fired power plants were about 6 million tons in 2015. Pollutants containing particulate matter 10, 2.5 (PM10, PM2.5), heavy metals and dioxins from coal-fired power plant. The emissions threaten the health of people who live near these power plants, as well as those who live hundreds of miles away. These pollutants that have long-term impacts on the environment because they accumulate in soil, water and animals. The present study is to investigate the physical and chemical characteristics of coal-fired power plant fly ash and bottom ash contains particulate matter, whose particulate sizes are lower than $PM_{10}$ and $PM_{2.5}$ and heavy metals. There are wide commercial technologies were available for monitoring the PM 2.5 and ultra-fine particles, among those carbonation technology is a good tool for stabilizing the alkaline waste materials. We collected the coal ash samples from different coal power plants and the chemical composition of coal fly ash was characterized by XRF. In the present laboratory research approach reveals that potential application of carbonation technology for particulate matter $PM_{10}$, $PM_{2.5}$ and stabilization of heavy metals. The significance of this emerging carbonation technology was improving the chemical and physical properties of fly ash and bottom ash samples can facilitate wide re use in construction applications.

• 한국지반공학회지:지반
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• 제11권2호
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• pp.37-50
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• 1995

최근 우리 나라의 경우 산업 발달과 함께 급속히 증가하는 전력 수요에 따라 화력발전소에서 발생되는 산업 부산물인 석탄회 처리 문제가 심각하게 대두되고 있다. 따라서 산업 부산물을 재활용하는 차원에서 석탄회를 성토재로 활용하기 위한 공학적 성질 개선 방안으로 안정제 혼합 효과를 구명하기 위하여 삼천포, 서천 화력 발전소에서 부산되는 석탄회 시료에 대해 시멘트와 석회를 안정제로 사용하여 석탄회의 혼합률, 장기 재령, 양생 온도 변화에 따른 강도 특성을 살펴보았으며, 동결융해시험, 압밀시험 그리고 투수 시험에 따른 내구성 증대, 압축성 및 투수성 감소특성을 검토 하였다. 연구 결과 매립회(coal ash)는 각종 성토 재료로 사용이 가능한 것으로 나타났으며, 특히 비회 (fly ash)는 2~3% 정도의 시멘트를 첨가함으로써 양호한 성토재로 사용할 수 있는 것으로 나타났고 동결 융해가 우려되고 지역에 성토재로 석탄회를 활용할 경우는 안정제를 6-9% 정도 적절히 혼합하여 사용하는 것이 효율적임을 알 수 있었다.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.458-464
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• 2011

Purpose: Metacarpal fractures are common hand injury that may require operative intervention to ensure adequate reduction and stabilization. Traditionally, titanium miniplate was used for rigid fixation of bone fractures. However, the use of permanent plate lends itself to multiple complications such as infection, exposure of the hardware, tendon adhesions, tendon rupture, prolonged pain, bony atrophy and osteoporosis (stress shielding), metal sensitization, and palpation under the skin. This study evaluated the usefulness and stability of biodegradable plates and screws for treatment of metacarpal bone fractures. Methods: There was 17 patients who had surgery for metacarpal bone fracture from April 2007 to June 2010. All patients had open reduction and internal fixation. We used absorbable plates and screws (Inion CPS$^{(R)}$) for internal fixation. Postoperative results were assessed with x-ray. Stability of plates and screws, healing process and its complications were observed by clinical and radiographic assessment. Results: All patients were successfully reduced of bone fracture, and fixations with absorbable plates and screws were stable. The mean follow up period was 7.1 months. 2 patients complained postoperative pain, but they were relieved with analgesics. All patients experienced transient stiffness, but they were relieved with active assistive range of motion after removal of splint. No patients suffered complications which could be occurred by using metallic plate. Conclusion: There was no critical complications such as re-fracture or nonunion among patients. No patients suffered side effects related with metallic implants. Biodegradable implants can offer clinically stable and attractive alternative to metallic implants to stabilize metacarpal bone fractures in the hand.

• The Journal of Korean Physical Therapy
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• 제34권5호
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• pp.205-211
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• 2022

Purpose: This study investigated the effects of an intervention that combined the abdominal drawing-in maneuver and frequency-specific neuromuscular electrical stimulation on changes in trunk muscle activity, muscle fatigue, and balance in stroke patients. Methods: Thirty stroke patients were randomly assigned to two groups. Fifteen subjects were assigned to group I which performed the abdominal drawing-in maneuver combined with low-frequency neuromuscular electrical stimulation and the other 15 subjects to group II where the abdominal drawing-in maneuver was combined with high-frequency neuromuscular electrical stimulation. Muscle activity and fatigue were measured using surface electromyography before the intervention. Balance was measured using the Trunk Impairment Scale and re-measured after six weeks of intervention for comparative analysis. Results: Both groups showed a significant increase in muscle activity and balance (p<0.05), and there was no significant difference between the groups (p>0.05). In the changes in muscle fatigue, only the experimental group II showed a significant increase in muscle fatigue (p<0.05). The difference between the groups was statistically significant (p<0.05). Conclusion: It was confirmed that among stroke patients, the combination of the abdominal drawing-in maneuver and low-frequency neuromuscular electrical stimulation was more effective in changing the muscle activity and balance of the trunk by minimizing the occurrence of muscle fatigue compared to the combination of the abdominal drawing-in maneuver and high-frequency stimulation. These results can be used as basic data for clinical trunk stabilization training.

• 대한토목학회논문집
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• 제30권1B호
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• pp.81-87
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• 2010

쌍치 수위관측소는 과거 12년 동안 봉부자로 유량을 측정해왔다. 그러나 수위-유량관계곡선의 전이가 수용할 수 없을 만큼 너무 크다. 전이를 분석해 보기 위하여 주요인자들을 검토하였고, 특히 부자법에 의한 유량 산정을 위해서는 두 단면이 필요하나, 상 하단측선의 관측수위가 없어 수위관측소의 수위만을 사용하여 계산된 오류를 교정하였다. 이를 위해서 기준 수위-유량관계곡선을 작성하였다. 본 연구에서는 기준 수위-유량관계곡선에 대하여 RMA2모형으로 수면곡선을 모의하였다. 이를 바탕으로 기존유량을 재 산정하여 기존 수위-유량관계곡선을 재 작성하였다. 그 결과 전이의 변동 폭이 줄어들었으며 최근의 수위-유량관계곡선이 물리적으로 합당함을 확인하였다.

• 한국지반공학회논문집
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• 제30권2호
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• pp.53-64
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• 2014

이 연구에서는, 균질한 재성형 점토를 이용한 실내시험을 통해 정규압밀 영역에서의 하중재하기간이 점성토의 압축 및 장기압밀 특성에 미치는 영향을 명확히 하고자 하였다. 또한 각 하중재하기간에 따른 현장에서의 유효상재하중에 해당하는 초기압밀하중을 변화시킨 장기압밀 시험을 수행하여 표준압밀시험시의 하중단계별 재하방법과 하중재하기간의 증가에 따른 압축곡선의 특성을 비교/분석하여 하중재하기간에 따라 최종침하량을 예측하는 방법을 제안하고자 하였다. 연구 결과 하중재하기간에 따른 점성토의 압축특성은 초기압밀하중을 가한 후 하중재하기간이 증가할수록 주어진 단계에서의 압밀후반부의 2차압밀의 증가로 선행압밀하중이 약간씩 감소하는 경향을 나타내었다. 그와 동시에 2차압밀이 유사과압밀 현상 및 점토골격의 안정화를 유발하여 정규압밀영역에서의 압축지수에 미치는 영향은 미미했으며 과압밀영역에서는 유사과압밀 현상으로 재압축지수의 증가를 유발하는 것으로 나타났다.

• Journal of Preventive Medicine and Public Health
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• 제28권1호
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• pp.153-174
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• 1995

This study was conducted to examine the determinant factors for expenditure of the medical insurance program for self-employeds based on the analysis of 1991 'The Medical Insurance Program for Self-Employeds Statistical Yearbook', and also similar yearbooks in the metropolitan and other provinces. The major findings are as follows : We have divided benefits into these four components such as the utilization rate for out-patients, expenses per claim for out-patients as paid by the insurer, utilization rate for in-patients, and the expenses per claim for in-patients as paid by the insurer, in order to examine the determinant factors for it. The results of the study revealed the following findings, in urban areas, the supply of medical care had more influence on the benefits than other demographic and economic variables, while, in county areas, both the supply of medical care and the rate of those aged over 65 affected the provision of benefits. The determinant factors for financial balance of the medical insurance program for self-employeds are, first, the determinant factor for administrative expenses was the number of households. The more the number of households, the less the administrative expenses per the insured. This shows that the economy of scale is being. And so, the administrative district must be taken into consideration in the incorporation of small regional medical societies and should be re-organized for more efficient management. Second, in urban areas, the supply of medical care had more influence on utilization rate and expenses per claim as paid by insurer, and therefore it is necessary to control it. In county areas, the supply of medical care and the rate of those aged over 65 raised the utilization rate and expenses per claim as paid by insurer. For the financial stability of county areas, a common fund for medical care for the aged and expansion of finance stabilization fund would be necessary. But, in county areas, it would be unnecessary to control the supply of medical care because it was much more insufficient than in urban areas. The vitalization of public health facilities must be carried out in county areas, for they reduced benefits. Sice the more insured in a single household, the less the utilization of the medical insurance program, benefits for habilitation at home should be given consideration. The law of majority and the economy of scale were applied here, and therefore the incorporation of regional medical societies must be taken into consideration. In integrating regional medical societies, it would be absolutely necessary to review the structural differences among all regional medical societies, the medical demand of each region, and also the local characteristics of each region.

• 한국환경복원기술학회지
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• 제10권2호
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• pp.1-15
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• 2007

A variety of revegetation methods are being utilized and developed. However, most of revegetation methods used on highway slopes in Korea are based on foreign-introduced plant varieties to stabilize road surfaces and to administer afforestation for surface covering at an earlier phase. Therefore. it results in various problems. such as failure to achieve harmony with the surrounding vegetation and 10 cause re-denudation of slopes as the foreign-in introduced plant varieties wane out from 2~3 years after hydro-seeding, etc. In addition, some of the revegetation plants seeded in the earlier phase grow excessively high, thus causes successional problems, such as to inhibit the invasion of the secondary vegetation from the surrounding areas, etc. Therefore, in this study, 160 slopes located in the nationwide express highways have been investigated and analyzed in order to produce basic data for restoration of ecological environment in slopes created on a long-term basis by investigating and analyzing locational characteristics of cut and filled slopes in express highways, status of revegetation methods, characteristics of soil and plant-ecological environment. 1. Investigation on cut and embanked slopes in express highways was carried out in the total of 160 locations, which include 108 cut slopes and 52 embanked slopes. As a whole, the most frequently used revegetation method was seed spray, which was found to be used in the total of 55 target slops investigated. 2. Planting method of Wistaria floribunda applied to some of the blasted rock zones was found to cause damages as Wistaria floribunda trailed up the surrounding vegetation and the secondary invaded trees. In order to prevent this, this method must be used only in the lowest parts of large-sized slopes. Also, it will be required to administer continuous management and maintenance in the areas already planted with this plants. 3. The areas of blasted rock and ripping rock slopes were applied with coir net (net + seeding) method. However, many of these areas failed in achieving ground covering. Most areas where revegetation was in progress, they were covered with Eragrostis curvula(Weeping lovegrass) only. In areas with soil, such as decomposition of granite, where afforestation is difficult. In this slopes, soil base must be improved by hrdroseeding with thin-layer vegetation base application methods in order to achieve success in afforestation with native plants. 4. Woody species, rather than herb species, are more helpful in stabilization of slope surfaces. Therefore, it is important to be able to grow and protect woody species on highway slopes. Growth of woody vegetation is most largely influenced by soil depth. Thus, when hydro-seeding woody plants, it is recommended to apply at the upper layer of the slopes, which is capable to sufficiently provide the fundamentals required in plant growth.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3462-3468
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• 2015

2014~2015년 현 시점에서 발생되고 있는 수많은 네트워크 장애와 침해는 ISP(Internet Service Provider)가 제공하는 통신라인 등을 통해 접근하는 공격성향의 불법접근이 문제의 근원으로 나타나고 있다. 이와 같은 네트워크 기반의 공격에 대비한 방어방법으로 네트워크 통신을 위한 안정화 구조와 이에 준하는 다양한 정책 및 물리적 보안 장치와 솔루션들이 구현되고 구축되고 있다. 따라서 통신 대역폭 상의 논리영역을 구성하는 등의 네트워크 보안구간을 확보하기 위한 기초 연구자료와 네트워크 보안시장의 또 다른 연구 주제인 통신라인의 확충을 위해 제시되는 과제를 제안하고 네트워크 통신 대역폭을 이용한 능동적인 통신 대역폭 연동 패러다임이 물리적 보안을 이끄는 한 영역으로 필요성이 대두되어 졌음을 인지하는 과정이 필요해 졌다. 추가적으로 현재 통신사들이 제공하는 통신용량을 기준으로 이를 세분화된 조직 영역으로 재분할하고 분할된 각 영역별 통신 용량의 논리적 가상화를 적용함으로써 가시적 보안구조 구성 형태의 자료들을 특정한 물리적 정보 범주에 모두 제한하는 것이 필요하다. 이는 기존의 물리적 구조를 논리영역 적용 기반의 네트워크 보안구간을 제안함으로써 물리적 네트워크 통신 구조를 설계하는 기초자료로 제공 되어질 것이다.

• 헤리티지:역사와 과학
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• 제44권3호
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• pp.62-77
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• 2011

아산 현충사에 전시중인 보물 제326호 이충무공유물은 장검 2점, 옥로 1점, 요대 1점, 도배 구대 2점으로 구성되어 있다. 이 유물은 장시간의 전시로 표면에 먼지가 많이 고착되었으며 금속이 부식되어 과거의 빛깔을 잃어버리고 있었다. 2011년 4월 28일 "충무공이순신기념관"을 개관하기 위한 준비 과정에서 유물의 상태점검 결과 보존처리가 필요하다고 판단하여 2011년 3월부터 4월까지 2개월에 걸쳐 보존처리를 실시하였다. 보존처리에 앞서 유물에 대한 분석을 실시한 결과 칼자루 붉은 색 안료 및 흑칠, 칼 도신 붉은 색 안료 등은 근래에 수리를 한 것을 확인하였다. 제작 당시의 것으로 추정되는 붉은 색 안료는 석간주(Hematite)이나 후대에 칠한 안료는 주사와 연단이 혼합된 안료이다. 칼 도신의 붉은 색 안료는 황연(Chrome Yellow, $PbCrO_4$)이다. 또한 비파괴 분석을 통해 칼 장식의 재질, 요대의 도금방법, 도배 구대의 재질 등을 확인하였다. 보존처리는 훼손 우려가 있는 부분에 대한 보존처리를 통해 안정한 상태로 전시될 수 있도록 하였다.