• Journal of the Korean Arthroscopy Society
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• v.5 no.2
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• pp.69-73
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• 2001

Purpose : To evaluate the clinical results and widening of bony tunnel after anterior cruciate ligament(ACL) reconstruction using hamstring tendon with Ligament Anchor(LA) screw, which is newly designed fur fixation of graft into femur. Materials and Methods : Fifty eight patients who were followed up at least more than 2 years after ACL reconstruction with four strands of Hamstring tendon were included in this study. The graft was fixed with LA screw at femoral tunnel and with bioabsorbable interference screw at tibial tunnel. The average period of follow-up was 28 months. The clinical results such as physical examination and Lysholm knee score and radiological results. widening of bony tunnel and instrumented anterior laxity test with $Telos^{\circledR}$(Telos stress device; Austin & Associates, Inc., Polston, US) were evaluated. Results . The Lysholm knee score was 60.0 in average preoperatively and improved to 94.0 in average at follow up. On the Lachman test, there were mild(+) instability in 16 cases, moderate(++) in 24, severe(+++) in 18 preoperatively. 50 cases were converted to negative and 8 to mild instability at follow up. On instrumented anterior laxity test with $Telos^{\circledR}$, side to side difference in 20 lb was 12.9mm in average preoperatively, and was decreased to 3.1mm in average follow-up. The femoral tunnel was widened from 10.6mm postoperatively to 12.7mm$(21.1\%)$ at follow up on antero-posterior plane and from 10.7mm to 12.4mm$(16.5\%)$ on lateral plane. Tibial tunnels was also widened from 9.8mm to 11.8mm$(20.7\%)$ on antero-posterior plane and from 9.9mm to 11.7mm$(18.9\%)$ in lateral plane. Conclusion : ACL reconstruction with hamstring tendon and LA screw was one of the choice of grafts and fixatives in restoring knee stability and in improving clinical results with little complications such as excessive widening of bony tunnel.

• Journal of the Korean Arthroscopy Society
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• v.12 no.2
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• pp.112-117
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• 2008

Purpose: Double-bundle reconstruction of anterior cruciate ligament(ACL) has the advantage of restoring the isometry and original function of ACL. The purpose of this study is to evaluate the clinical results following double-bundle reconstruction of ACL using autogenous hamstring grafts through an accessory anteromedial portal. Materials and Methods: From January 2005 to July 2006, sixty patients(52 males, 8 females) underwent double-bundle ACL reconstruction using autogenous hamstring tendons..The mean age was 31.7 years($20{\sim}51$ years). The mean follow up period was 13.4 months($12{\sim}16$ months). We made a horizontal-oblique skin incision just medial to tibial tuberosity and harvested semitendinosus and gracilis tendon. Tibial tunnel for posterolateral bundle was made near its anatomical position. By modifying an anatomic reconstruction of ACL by Yasuda et al., we made a femoral tunnel for posterolateral bundle through accessory anteromedial portal. Tunnels for anteromedial bundle were made with conventional method. We reconstructed anteromedial bundle with semitendinosus tendon and posterolateral bundle with gracilis tendon. Clinical results at last follow up were evaluated by range of motion, extent of anterior displacement(KT-1000 arthrometer), pivot-shift test. Functional evaluation of clinical outcomes were evaluated by Lysholm score and modified Feagin Scoring System. Results: There was no limitation of motion of knee joint at last follow up. Mean side to side difference of anterior displacement of tibia by KT-1000 arthrometer was improved from 8.4 mm preoperatively to 1.7 mm postoperatively(p<0.05). Average Lysholm score was improved from 64.1 preoperatively to 92.2 postoperatively(p<0.05). In modified Feagin Scoring System, 90% of cases were rated as good or excellent. Conclusion: Double-bundle reconstruction of ACL using autogenous hamstring grafts through accessory anteromedial portal results in good clinical outcomes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.349-358
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• 2014

This study was conducted to determine the impact of elevated temperature in growing season on the growth and fruit quality of red pepper (Capsicum annuum L.) by cultivating pepper in the temperature gradient tunnels. Plant height, stem diameter, leaf number and total leaf area, fresh weight and dry weight increased at ambient $+2^{\circ}C$ temperature, whereas each leaf area decreased as temperature increased. The plants grown under ambient $+2^{\circ}C$ temperature showed the greatest number of flower and fruit. Fruit weight, fruit length and fruit diameter decreased as the temperature increasing gradually. Total fruit number, total fruit weight and total dry fruit weight was the highest at ambient $+2^{\circ}C$ temperature. Major free sugars of red pepper fruit were fructose and glucose. Free sugar content of red pepper according to the differences in harvesting times and in growth temperature showed a little differences. The yield of red pepper fruit at ambient $+2^{\circ}C$ temperature increased by 13% compared with the control. However, the yield of red pepper fruit at ambient $+4^{\circ}C$ temperature decreased by 20% as compared to control. Non-marketable fruits (diseased fruit, malformed fruit and small sized fruit) increased as the temperature rised.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.95-107
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• 2017

In this study, a preliminary study was undertaken for development of a tunnel incident automatic detection system based on a machine learning algorithm which is to detect a number of incidents taking place in tunnel in real time and also to be able to identify the type of incident. Two road sites where CCTVs are operating have been selected and a part of CCTV images are treated to produce sets of training data. The data sets are composed of position and time information of moving objects on CCTV screen which are extracted by initially detecting and tracking of incoming objects into CCTV screen by using a conventional image processing technique available in this study. And the data sets are matched with 6 categories of events such as lane change, stoping, etc which are also involved in the training data sets. The training data are learnt by a resilience neural network where two hidden layers are applied and 9 architectural models are set up for parametric studies, from which the architectural model, 300(first hidden layer)-150(second hidden layer) is found to be optimum in highest accuracy with respect to training data as well as testing data not used for training. From this study, it was shown that the highly variable and complex traffic and incident features could be well identified without any definition of feature regulation by using a concept of machine learning. In addition, detection capability and accuracy of the machine learning based system will be automatically enhanced as much as big data of CCTV images in tunnel becomes rich.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.1102-1139
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• 2002

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2000 and 2001 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD technologies were widely applied for developing facilities and their systems. (2) Most of papers related with heat transfer analysis and heat exchanger shows dealt with convection, evaporation, and channel flow for the design application of heat exchanger. The numerical heat transfer simulation studies have been peformed and reported to show heat transfer characteristics. Experimental as well as numerical studies on heat exchanger were reported, while not many papers are available for the system analysis including heat exchanger. (3) A review of the recent studies on heat pump system shows that performance analysis and control of heat pump have been peformed by various simulations and experiments. The research papers on multi-type heat pump system increased significantly. The studies on heat pipe have been examined experimently for change of working characteristics and strut lure. Research on the phase change has been carried out steadily and operation strategies of encapsulated ice storage tank are reported experimentally in several papers. (4) A review of recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. Evaporation and condensation heat transfer characteristics are investigated for tube shapes and new alternative refrigerants. Studies on components of refrigeration/air conditioning system are carried to examine efficiency for various compressors and performance of new expansion devices. In addition to thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out, however research works on two-phase flow seemed to be insufficient. (5) A review of the recent studies on absorption cooling system indicates that heat and mass transfer phenomena have been investigated to improve absorber performance. Various experimental data have been presented and several simulation models have been proposed. A review of the recent studies on duct and ventilation shows that ventilation indices have been proposed to quantify the ventilation performance in buildings and tunnels. Main efforts have been focused on the applications of ventilation effectiveness in practice, either numerically using computational fluid dynamics or experimentally using tracer gas techniques. (6) Based on a review of recent studies on indoor thermal environment and building service systems, research issues have mainly focused on many innovative ideas such as underfloor air-conditioning system, personal environmental modules, radiant floor cooling and etc. Also, the new approaches for minimizing energy consumption as well as improving indoor environmental conditions through predictive control of HVAC systems, various activities of building energy management and cost-benefit analysis for economic evaluation were highlighted.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.203-211
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• 2014

Tunnel reduces travel time as and it is essential facilities for the eco-friendly road construction. In recent years, It has been accelerating the tunnel construction to provide a higher level of traffic service but a driver driving in the narrow and dark tunnel takes characteristically psychological anxiety and the restriction of the sight. Moreover, A driver passing through more than 1,000m long tunnel, as to pass inside the monotonous form of the tunnel for a long time can cause drowsiness and increase the driver load. This driver load can degrade road-holding of the inside of the long tunnel highly and pose a high risk of accidents. Accordingly, In this study is to present the proper length of the Tunnel, considering the characteristics of traffic accident. For this, this study is that the long tunnel that affects traffic safety traffic safety variables are selected and classified. Traffic safety variables are classified in detail as a variable of the traffic accident and velocity one, the applicable variables the number of the traffic accident, the ratio of the traffic accident, driving velocity, the individual vehicle velocity etc. Traffic safety variables are categorized as more than a pole length of the tunnel in order to examine its impact on correlation analysis. The results indicate significant results in traffic accidents in accordance with traffic accidents, traffic safety, selects the variable was Variable depending on the length of the tunnel traffic safety point of significantly increasing the possibility of an accident can be seen as a high point. And the point of the Distribution of selected variables in order to create a traffic safety was a significant increase in traffic safety variables was set at critical intervals. Before reaching the critical point and the corresponding length of the long tunnel was set at the proper length. In this study, the optimum length of the proposed long tunnel through the long tunnel that occur in the future to contribute to reducing traffic accidents would be able to be determined.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.195-199
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• 2002

This article is to report a new technique for reconstruction of the anteromedial and posterolateral bundles of anterior cruciate ligament by separate tensioning and fixation of the each bundle. Method : Tibial and femoral tunnels were made with conventional technique of anterior cruciate ligament reconstruction. Tibial tunnel was enlarged $5\~7$ mm in anterior-posterior direction to make oval it in cross section. When preparing the Achilles tendon allograft, bone plug portion was trimmed as the conventional technique. The tendinous portion was trimmed as two separate bundles by dividing the tendinous portion longitudinally, so the graft is shaped like 'Y'. The bone plug portion of allograft was inserted into the femoral tunnel and fixed with absorbable cross pins. Two ligamentous portionss of the distal part of the grafts were tensioned separately at the external orifice. Anteromedial bundle was fastened under maximum tension with the knee flexed 90 degrees by post-tie method. The posterolateral bundle was fixed by the same technique with the knee in full extension. Then, an absorbable interference screw was inserted between the two bundles upto the upper end of the tibial tunnel, to get more initial rigidity of the reconstructed graft as well as to locate the two bundles in more anatomic position.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.429-440
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• 2014

Since the World Trade Center and Pentagon attacks in 2001, terror, military attack, or man-made disaster caused impact, explosion, and fire accident have frequently occured on civil infrastructures. However, structural behavior researches on major Prestressed Concrete (PSC) infrastructures such as bridges, tunnels, Prestressed Concrete Containment Vessel (PCCVs), and LNG tanks under extreme loading are significantly lacking. Especially, researches on possible secondary fire scenarios after terror, bombing, collision of vehicles and vessels on concrete structures have not been performed domestically where most of the past researches related to extreme loadings on structures focused on an independent isolated extreme loading scenario. Due to the outcry of public concerns and anxiety of potential terrorist attacks on major infrastructures and structures, a study is urgently needed at this time. Therefore, in this study, the bi-directional prestressed concrete $1400{\times}1000{\times}300mm$ panels applied with 430 kN prestressing force using unbonded prestressing thread bars were experimentally evaluated under impact, fire, and impact-fire combined loadings. Due to test site restrictions, impact tests were performed with 14 kN impactor with drop heights of 10m and 3.5 m to evaluate impact resistance capacity. Also, fire and impact-fire combined loading were tested using RABT fire loading curve. The measured residual strength capacities of PSC and RC specimens applied with impact, fire, impact-fire combined loadings were compared with the residual strength capacity of undamaged PSC and RC specimens for evaluation. The study results can be used as basic research data for related research areas such as protective design and numerical simulation under extreme loading scenarios.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.593-608
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• 2018

If a problem occurs in the strut during the construction of the braced wall, they may cause excessive deformation of the braced wall. Therefore, in this study, the behavior of the braced wall and existing tunnel adjacent to excavation were investigated assuming that the support function of strut is lost during construction process. For this purpose, a series of model test was performed. As a result of the study, the earth pressure in the ground behind wall was rearranged due to the deformation of the braced wall, and the ground displacements caused the deformation of adjacent tunnels. When the struts located on the nearest side wall from the tunnel were removed, the deformation of the braced wall and the tunnel deformation were the largest. The magnitude of transferred earth pressure depended on the location of tunnel. The increase of the cover depth of tunnel from 0.65D to 2.65D caused the increase of the earth pressure by 25.6%. As the distance between braced wall and tunnel was increased from 0.5D to 1.0D, the transferred earth pressure increased by 16% on average. Horizontal displacements of braced wall by the removal of the strut tended to concentrate around the removed struts, and the horizontal displacement increased as the strut removal position is lowered. The tunnel displacement was maximum, when the cover depth of tunnel was 1.15D and the horizontal distance between braced wall and the side of tunnel was 0.5D. The minimal displacement occurred, when the cover depth of tunnel was 2.65D and the horizontal distance between braced wall and the side of tunnel was 1.0D. The difference between the maximum displacement and the minimum displacement was about 2 times, and the displacement was considered to be the largest when it was in the range of 1.15D to 1.65D and the horizontal distance of 0.5D.

• Journal of the Korean Arthroscopy Society
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• v.8 no.1
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• pp.19-25
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• 2004

Purpose: To compare the results of two different autografts used to reconstruct the anterior cruciate ligament(ACL): bone-patellar tendon-bone and quadruple hamstring tendon. Materials and Methods: Forty one cases (20 bone-patellar tendon-bone cases and 21 quadruple hamstring tendon cases) were followed up more than 2 years postoperatively. Patellar tendons were fixed with interference screws and hamstring tendons were fixed with cross pins and intrafix sheaths and screws. Follow-up results were evaluated with KT-2000 arthrometer, International knee Documentation Committee(IKDC) evaluation form and follow up X-ray Donor site morbidity was analysed. Results: Final IKDC) scores more than B grade and side to side differences of manual maximum test using KT-2000 arthrometer showed insignificant differences(p>) between the two groups. Plain radiographs of hamstring group showed marked widening of the femoral and tibial tunnels at postoperative 2 years. Patellar tendon group showed 30% rate of anterior knee complications. Conclusion: ACL reconstruction using autogenous hamstring graft with new fixation method showed comparable clinical results to using autogenous patellar tendon graft with fewer anterior knee symptoms.