• Clean Technology
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• v.12 no.4
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• pp.238-243
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• 2006

The aggregate properties of chilled converter slag reformed by atomizing liquid converter slag were investigated. The properties of mortars with various replacement of standard sand by chilled converter slag as recycled fine aggregates were investigated. The particle shape of chilled converter slag by atomizing was a sphere with an open cavity which is enclosed with two layers like a bored coconut. Specific gravity, unit weight and fineness modulus increased with increasing the replacement, and solid content had the maximum at the replacement of 75% and water absorption rate had the minimum at the replacement. The hardened mortars with higher replacements have the higher specific gravity and the denser texture.

• Korean Journal of Materials Research
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• v.8 no.5
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• pp.399-407
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• 1998

본 연구에서는 LCD패키지용 이방성 전도 필름의 전기적, 기계적 특성 및 신뢰성에 미치는 접속 변수의 영향을 연구하였다. 이방성 전도 필름을 통한 전기적 전도 현상을 각각의 도전 입자와 기판 사이의 기계적 접촉에 의해 접촉 방향으로만 전류가 흐르게 되는 것이 주되는 전도 기구이다. 따라서 접속 압력에 따라 각각의 도전 입자의 변형으로 기판 사이의 접촉 면적이 변하는데 이방성 전도필름의 접촉 저항은 이런 접촉 변화에 의해 결정된다. 접속 압력에 따라 초기에 접촉 저항은 감소하다가 점차 접촉 저항기가 안정화되는 거동을 보였다. 그러나 높은 접속 압력에서는 오히려 저항치가 약간 증가함을 보였다. 이방성 전도 필름 접속의 접착력을 평가하기 위해 필 테스트(peel test)를 시행하였는데, 접속 압력과 접속 온도를 증가 시킬수록 이방성 전도 필름 접속의 접착력을 평가하기 위해 고온 시효 시험, 온도 사이클링 시험, 고온 고습 시험의 신뢰성 시험을 시행하였으며, 이중 고온 고습 시험이 ACF접속의 전기적, 기계적 특성에 가장 악영향을 주었다. 또 큰 압력으로 접속된 것보다 작은 압력으로 접속되었을 때, 그리고 도전입자로는 금속 코팅 된 폴리머 입자가 사용될 때 신뢰성이 상대적으로 좋은 것을 발견했다.

• The Science & Technology
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• no.3 s.418
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• pp.34-37
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• 2004

5만년인가, 4천년인가. 문화재청은 지난 2월 6일 제주도 남제주군 대정읍 상모리와 안덕면 사계리 해안에서 사람 발자국 화석 100여 점과 동식물 화석 수천점을 발견했다고 발표했다. 화석 발견 지층의 생성 시기는 구석기 중기인 5만년전으로 추정되며 선사인류 발자국 화석은 한국교원대 김정률 교수팀이 지난해 10월 처음 발견했다. 경북대 양승영 명예교수는“사람 발자국 화석은 재주도를 포함한 한반도와 중국 대륙이 육로로 연결됐다는 가설을 뒷받침해주는 증거물”이라는 견해를 밝혔다. 선사시대 인류발자국의 발견은 세계에서 7번째이며 함께 발견된 코끼리와 말 발자국은 당시 한반도가 온대 지역이 아닌 아열대 지역이었을 가능성을 제기했고, 말의 기원이 몽골에서 유래되었다는 기존 주장을 바꾸는 계기가 될 것으로 보인다. 그러나, 화석 발자국 발표 이후, 관련학자들간에 이견이 생겼다. 일부 학자들이 연대측정에 의문을 제기하고, 제주도 지층은 4천년 전에 생성된 것이며 ‘5만년 전 추정’에는 무리가 있다는 지적이었다. 한 인류의 이동을 추정하는 데는 5만년 전과 4천년 전은 엄청난 역사적 차이가 있다. 아프리카 대륙에서 시작 된 인류의 조상이 중국과 북방육로를 통해 한반도까지 이동해왔다는 지금까지 학계의 통설은 뒤집힐 것인가. 제주도의 사람 발자국 화석은 그 절대 연대가 정확히 측정된다면 한반도 인류의 일부가 중국 남방의 육로나 해로를 통해서 이동해왔을 가능성이 있다는 새로운 사실을 밝혀줄 것이다. 현대 과학이 연대측정기술을 발달시켜서 역사를 풀어나가기 시작한 것은 겨우 50여년 전으로 일천하기만 하다. 그러나, 그 학문의 깊이는 지구 나이 45억년을 밝혀냈고, 35만년 전 유기물의 생성을 추정해내는 등 심오한 경지에 이르고 있다. 현대과학의 연대측정방법론을 소개한다.

• Resources Recycling
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• v.8 no.5
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• pp.19-27
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• 1999

The desilica~ilalioc~h~ar .~ctcrisocs or conveutcu dust for molten pg iron has bee11 sludled for the pulposc of converter dust reuse. Desiloconizalir~ne ff~c~encwya s observed 10 be increased with increasing feeding rate of dust, and there was 110 cffccl to Lhe des~lica~~iratiearlfli cio~cyfo r the addtioolI CaO Ln dust. In ~noslc ases, the dcs~l~conizaliornea ction was ucconlpl~shed wrthin 10 minutes regadless of thc dust cornpasilim In addition lo the desil~comzat~oenfl ect, the rzmow~lc hal-i~cteristo~fs M u, P. C, and S from mallen iron by convcrtcr dust also have been in\~esligataled. CuO m thc converlel. dust was observed to ~educc the demanganizi~tion eflect and slag laming phenomenon and make thc dephosphoriralion pn,ce*s easler.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.2
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• pp.247-255
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• 2024

Development of electronic warfare(EW) software has become increasingly challenging due to stricter regulations, shorter development cycles, and increased reliability testing. Consequently, software development often proceeds without proper architecture design, which can lead to missing critical quality requirements and potential system redesigns. In this study, we propose using Attribute-Driven Design(ADD) 3.0 to design software architecture specifically tailored for EW systems, enabling a more systematic approach to address quality requirements. The paper presents an overview of EW software and ADD 3.0 methodology, followed by an analysis of the architecture design results using static and dynamic views. The paper concludes by discussing the effectiveness of the proposed architecture design.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.422-427
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• 1999

Background: Tachycardia induced heart failure model would be the model of choice for the dilated cardiomyopathy. This more closely resembles the clinical syndrome and does not require major surgical trauma, myocardial ischemia and pharmacological or toxic depression of cardiac function. When heart failure is progressive, application of new surgical procedures to the faling heart is highly risky. It has been shown that recovery trajectory from heart failure is a new method in decreasing animal mortality. The purpose is to establish the control datas for recovery trajectory in the canine heart failure model. Material and Method: 21 mongrel dogs were studied at 4 stages(baseline, at the heart failure, 4 and 8 weeks after recovery). Heart failure was induced during 4 weeks of continuous rapid pacing using a pacemaker. Eight weeks of trajectory of recovery period was allowed. Indices of left ventricular function and dimension were measured every 2 weeks and the hemodynamics were measured by use of Swan-Ganz catheterization and thermodilution method every 4 weeks. Values were expressed as mean${\pm}$standard deviation. Result: 4(20%) dogs died due to heart failure. Left ventricular end-diastolic volume at the 4 stages were 40.8${\pm}$7.4, 82.1${\pm}$21.1, 59.9${\pm}$7.7 and 46.5${\pm}$6.5ml. Left ventricular end-systolic volume showed the same trend. Ejection fractions were 50.6${\pm}$4.1, 17.5${\pm}$5.8, 36.3${\pm}$7.3, and 41.5${\pm}$2.4%. Blood pressure and heart rate showed no significant changes. Pressures of central vein, right ventricle, pulmonary artery, and pulmonary capillary wedge showed significant increase during the heart failure period, normalizing at the end of recovery period. Stroke volumes were 21.5${\pm}$8.2, 12.3${\pm}$3.5, 17.9${\pm}$4.6, and 15.5${\pm}$3.4ml. Blood norepinephrine level was 133.3${\pm}$60.0pg/dL at the baseline and 479.4${\pm}$327.3pg/dL at the heart failure stage(p=0.008). Conclusion: Development of tachycardia induced heart failure model is of high priority due to ready availability and reasonable amenability to measurements. Recovery trajectory after cessation of tachycardia showed reduction of cardiac dilatation and heart function. Application of new surgical procedures during the recovery period could decrease animal mortality.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.364-370
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• 2014

The nutrient and irrigation management of scion and rootstock can alleviate stress on grafted transplants after grafting and promote the growth. This study investigated the effects of nutrient and irrigation management of scion and rootstock on the graft-take and growth of grafted pepper transplants. Before grafting, the scions were subjected to different water potential regimes in media by controlling the irrigation frequency and time. The scions were subirrigated 0, 1(two days before grafting), 1(one days before grafting) or 2 times for five days before grafting. The irrigation frequency and time influenced the water potential of media and the growth of scion and grafted transplants. At 13 days after grafting, fresh and dry weight of transplants which were irrigated once at two days before grafting were greater by 29 and 34% than those without irrigation during five days before grafting. This suggests that mild water stress on scion prior to grafting by controlling water management alleviate water stress on grafted transplants after grafting and improve the growth. Before grafting, the rootstocks were subjected to different nutrient regimes by controlling nutrient solution application. The rootstocks were supplied with nutrient solution 0, 1, 2, or 4 times. The nutrient application frequency and time influenced the electrical conductivity (EC) and pH of media. Accordingly, the growth and mineral contents of rootstock and grafted transplants were also affected. At 13 days after grafting, fresh and dry weight of transplants with four times of nutrient application increased by 30 and 20%, respectively, than those without nutrient solution supply during seven days before grafting. Therefore, it is recommended that nutrient solution be supplied more than four times during seven days before grafting for the production of high quality transplants.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.441-448
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• 2015

This study aims to suggest a reasonable signal operation method for right-turn traffic management. It was found that the right-turn vehicle supplementary signal is currently operated without clear regulations or criteria. It was also analyzed that right-turn supplementary signals are used without consistency, there is a risk of traffic accidents due to the discordance between supplementary signals and traffic signals of forward vehicles, there is a lack of basis for prohibition of a right turn when right-turn vehicle's supplementary signal is red and the flashing red signal is used in a different sense from the law. In order to see the effect of the installed right-turn vehicle supplementary signals on traffic signal violation, a field investigation was conducted. As the result, there was a high proportion of signal violation on the approach lane with right-turn supplementary signals and this means that right-turn supplementary signals hardly influenced the reduction in proportion of signal violation during a right turn. Additionally, a survey was carried out to see if there were differences in driver's interpretation of traffic signals depending on the installation of right-turn supplementary signals. As the result of the survey, there were no differences in interpretation of traffic signals depending on the installation of right-turn supplementary signals or the types of right-turn supplementary signals. A right turn when the signal was red did not lead to serious traffic accidents, so it is thought that there should be a careful consideration of a total ban on a right turn when the signal is red, in order to prevent driver's confusion due to the change of the signal system. Unless there is a disturbance to cars and pedestrians after a temporary stop when the signal is red, there is a need to specify that vehicles must stop temporarily in the Road Traffic Act to facilitate a right turn. What this study finally suggested is to use tri-colored arrow signals for right-turn car supplementary signals to convey a signal to a driver clearly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.868-876
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• 2014

This study was performed to investigate the effects of lactic-fermented rice flour on the quality characteristics of pan-fried food (Jeon). Pan-frying flour containing 5~20% lactic fermentation rice flour mixture was prepared. In rapid visco analyzer examination, peak viscosity, trough, final viscosity, breakdown, and setback of the lactic-fermented rice flour mixture were lower than those of rice flour or wheat flour. The L-value (lightness) of Jeon decreased with increasing the ratio of lactic-fermented rice flour. On the other hand, a-value (redness) and b-value (yellowness) increased with increasing ratio of lactic-fermented rice flour. Texture profiles showed that Jeon prepared with lactic-fermented rice flour mixture had higher springiness and gumminess than 100% rice flour. The oil absorptions of Jeon prepared with 100% rice flour and 20% lactic-fermented rice flour were 7.5% and 6.33%, respectively. For digestive properties, Jeon prepared with lactic-fermented rice mixture showed a greater amount of rapidly digestible starch and lower amount of slowly digestible starch. In the sensory evaluation, Jeon prepared with lactic-fermented rice mixture showed higher scores for appearance, flavor, and taste than others (rice flour and wheat flour). Especially, Jeon prepared with 10% lactic-fermented rice mixture showed the highest overall preference. In conclusion, the results demonstrate that lactic-fermented rice flour may prove quite useful as a pan-frying flour with desirable qualities properties.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.258-265
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• 2010

The purposes of this study was to determine the effects of limited hyperextension at knee joint using Limited Motion Knee Brace on balance and walking in patients with hemiplegia. The subjects of this study were 20 post-stroke hemiplegic patients admitted. Subjects were randomly assigned to either experimental group (Limited Motion Knee Brace group) or control group (manual restriction group). Both groups received traditional physical therapy intervention. The effects of each therapeutic method were evaluated by measurements of gait ability assesment, Berg balance scale (BBS), 10-meter walk speed (10MWS), Timed Up & Go (TUG) Test. The results of this research were as followings: (1) After treatment, there were significant BBS scores differences in both experimental and control group compared with pre-treatment(p<0.05). (2) After treatment, there were significant TUG test scores differences in both experimental and control group compared with pre-treatment (p<0.05). (3) After treatment, there were significant 10MWS differences in both experimental and control group compared with pre-treatment (p<0.05). (4) There were significant BBS scores differences in third and fourth week between experimental and control group (p<0.05). It was concluded that Limited Motion Knee Brace was effective for improving balance and for reducing fatigue for experimental group. Therefore, further studies are required to investigate the effect of knee orthosis for improving balance and walking in patients with hemiplegia.