• Polymer(Korea)
• /
• v.30 no.6
• /
• pp.486-491
• /
• 2006

Heterogeneous membranes were prepared by compression molding for the recovery of ammonium ion from waste water. Degree of sulfonation for sulfonated ion exchange resin increased with increasing amount of chlorosulfonic acid. It was 3.32 meq/g at 10 vol%. The tensile strength and elongation of the heterogeneous membrane was decreased with increasing contents of ion exchange resin. The tensile strength for LLDPE matrix membrane was the highest and also the elongation for EVA matrix membranes were the highest. The water content of heterogeneous membrane was increased with increasing contents of ion exchange resin. The maximum value of transport number for PE matrix membrane was 0.973. The electrical resistance of LLDPE matrix membrane was the lowest. It was value of $10.36{\Omega}/cm^2$ at 70 wt% resins.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.3A
• /
• pp.201-209
• /
• 2010

Generally, PSC girder bridge uses total gross cross section to resist applied loads unlike reinforced concrete member. Also, it is used as short and middle span (less than 30 m) bridges due to advantages such as ease of design and construction, reduction of cost, and convenience of maintenance. But, due to recent increased public interests for environmental friendly and appearance appealing bridges all over the world, the demands for longer span bridges have been continuously increasing. This trend is shown not only in ordinary long span bridge types such as cable supported bridges but also in PSC girder bridges. In order to meet the increasing demands for new type of long span bridges, PSC hollow box girder with H-type steel as compression reinforcements is developed for bridge with a single span of more than 50 m. The developed PSC girder applies compressive prestressing at H-type compression reinforcements using unbonded PS tendon. The purpose of compressive prestressing is to recover plastic displacement of PSC girder after long term service by releasing the prestressing. The static test composed of 4 different stages in 3-point bending test is performed to verify safety of the bridge. First stage loading is applied until tensile cracks form. Then in second stage, the load is removed and the girder is unloaded. In third stage, after removal of loading, recovery of remaining plastic deformation is verified as the compressive prestressing is removed at H-type reinforcements. Then, in fourth stage, loading is continued until the girder fails. The experimental results showed that the first crack occurs at 1,615 kN with a corresponding displacement of 187.0 mm. The introduction of the additional compressive stress in the lower part of the girder from the removal of unbonded compressive prestressing of the H-type steel showed a capacity improvement of about 60% (7.7 mm) recovery of the residual deformation (18.7 mm) that occurred from load increase. By using prestressed H-type steel as compression reinforcements in the upper part of cross section, repair and rehabilitation of PSC girders are relatively easy, and the cost of maintenance is expected to decrease.

• Journal of Korean Neurosurgical Society
• /
• v.51 no.4
• /
• pp.191-198
• /
• 2012

Objective: Valproic acid (VPA), as known as histone deacetylase inhibitor, has neuroprotective effects. This study investigated the histological changes and functional recovery from spinal cord injury (SCI) associated with VPA treatment in a rat model. Methods: Locomotor function was assessed according to the Basso-Beatlie-Bresnahan scale for 2 weeks in rats after receiving twice daily intraperitoneal injections of 200 mg/kg VPA or the equivalent volume of normal saline for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. Results: Basso-Beatlie-Bresnahan scale scores in rats receiving VPA were significantly higher than in the saline group (p<0.05). The cavity volume in the VPA group was Significantly reduced compared with the control (saline-injected) group (p<0.05). The level of histone acetylation recovered in the VPA group, while it was significantly decreased in the control rats (p<0.05). The macrophage level was significantly decreased in the VPA group (p<0.05). Conclusion: VPA influences the restoration of hyperacetylation and reduction of the inflammatory reaction resulting from SCI, and is effective for histology and motor function recovery.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.5
• /
• pp.1107-1115
• /
• 2017

The most commonly used PKZIP format is a ZIP file, as well as a file format used in MS Office files and application files for Android smartphones. PKZIP format files, which are widely used in various areas, require structural analysis from the viewpoint of digital forensics and should be able to recover when files are damaged. However, previous studies have focused only on recovering data or extracting meaningful data using the Deflate compression algorithm used in ZIP files. Although most of the data resides in compressed data in the ZIP file, there is also forensically meaningful data in the rest of the ZIP file, so you need to restore it to a normal ZIP file format. Therefore, this paper presents a technique to recover a damaged ZIP file to a normal ZIP file when given.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.20 no.6
• /
• pp.43-51
• /
• 2010

It is meaningful to investigate data in unallocated space because we can investigate the deleted data. Consecutively complete file recovery using the File Carving is possible in unallocated area, but noncontiguous or incomplete data recovery is impossible. Typically, the analysis of the data fragments are needed because they should contain large amounts of information. Microsoft Word, Excel, PowerPoint and PDF document file's text are stored using compression or specific document format. If the part of aforementioned document file was stored in unallocated data fragment, text extraction is possible using specific document format. In this paper, we suggest the method of extracting a particular document file text in unallocated data fragment.

• Journal of Korean Foot and Ankle Society
• /
• v.13 no.2
• /
• pp.162-168
• /
• 2009

Purpose: To evaluate the efficiency of the minimally invasive percutaneous plate osteosynthesis (MIPPO) with locking compression plate (LCP) for distal tibial metaphyseal intra-articular fracture compared with extra-articular fracture. Materials and Methods: From February 2006 to June 2008, 21 patients with distal tibia metaphyseal intra-articular fracture and 20 patients with extra-articular fracture were treated operatively by MIPPO technique with LCP and followed for at least one year. In the group with intra-articular fracture, mean age was 48.85 years old and a mean follow-up was 15 months. In the other group with extra-articular fracture, mean age was 52.35 years old and a mean follow-up was 14.5 months. The type of fracture was evaluated using the AO/OTA classification and open-fractures were according to the Gustilo-And gron classification. Radiologic evaluation with fracture healing and tibial alignment, clinical evaluation with Olerud and Molander ankle score and restriction of motion were done for treatment. Results: According to AO/OTA classification, There were 21 type A, 15 type B, 5 type C. Average union time of the intra-articular fracture (type B, C) was 18.7 weeks. Average union time of the extra-articular fracture (type A) was 17.1 weeks. All fractures were healed without malunion. There were no difference of mean restriction angle between intra-articular fracture (ankle dorsiflexion was 3.57 degree, plantar-flexion was 5.95 degree) and extra-articular fracture (ankle dorsiflexion was 3 degree, plantar-flexion was 3.75 degree). There were no difference of Olerud and Molander ankle score between them as a mean score of intra-articular and extra-articular was 89.25, 91.25 each other. As a complication, there were 3 case of skin necrosis, 8 case of discomfortable skin tenting by plate and 1 superficial infection, but could be healed by conservative care. Conclusion: MIPPO technique, combined articular reduction, with LCP of distal tibial metaphyseal fracture was a good method with high functional recovery.

• The Journal of the Korea Contents Association
• /
• v.8 no.5
• /
• pp.29-37
• /
• 2008

To transmit video bit stream over low bandwidth such as wireless channel, high compression algorithm like H.264 codec is exploited. In transmitting high compressed video bit-stream over low bandwidth, packet loss causes severe degradation in image quality. In this paper, a new algorithm for recovery of missing or erroneous motion vector is proposed. Considering that the missing or erroneous motion vectors in blocks are closely correlated with those of neighboring blocks. Motion vector of neighboring blocks are clustered according to average linkage algorithm clustering and a representative value for each cluster is determined to obtain the candidate motion vector sets. As a result, simulation results show that the proposed method dramatically improves processing time compared to existing H.264/AVC. Also the proposed method is similar to existing H.264/AVC in terms of visual quality.

• Journal of Korean Neurosurgical Society
• /
• v.44 no.3
• /
• pp.131-135
• /
• 2008

Objective : Hemifacial spasm (HFS) is considered as a reversible pathophysiological condition mainly induced by continuous vascular compression of the facial nerve root exit zone (REZ) at the cerebellopontine angle. As an offending vessel, vertebrobasilar artery tends to compress much more heavily than others. The authors analyzed HFS caused by vertebrobasilar artery and described the relationships between microsurgical findings and clinical courses. Methods : Out of 1,798 cases treated with microvascular decompression (MVD) from Jan. 1980 to Dec. 2004. the causative vessels were either vertebral artery or basilar artery in 87 patients. Seventy-nine patients were enrolled in this study. Preoperatively, computed tomography (CT) or brain magnetic resonance (MR) imaging with 3-dimentional short range MR technique was performed and CT was checked immediately or 2-3 days after anesthetic recovery. The authors retrospectively analyzed the clinical features. the compression patterns of the vessels at the time of surgery and treatment outcomes. Results : There were 47 were male and 32 female patients. HFS developed on the left side in 52 cases and on the right side in 27. The mean age of onset was 52.3 years (range 19-60) and the mean duration of symptoms was 10.7 years. Many patients (39 cases; 49.1%) had past history of hypertension. HFS caused only by the vertebral artery was 8 cases although most of the other cases were caused by vertebral artery (VA) in combination with its branching arteries. Most frequently, the VA and the posterior inferior cerebellar artery (PICA) were the simultaneous causative blood vessels comprising 32 cases (40.5%). and in 27 cases (34.2 %) the VA and the anterior inferior cerebellar artery (AICA) were the offenders. Facial symptoms disappeared in 61 cases (77.2%) immediately after the operation and 68 cases (86.1%) showed good outcome after 6 months. Surgical outcome just after the operation was poor in whom the perforators arose from the offending vessels concurrently (p<0.05). Conclusion : In case where the vertebral artery is a cause of HFS, commonly branching arteries associated with main arterial compression on facial REZ requires more definite treatment for proper decompression because of its relatively poor results compared to the condition caused by other vascular compressive origins.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.26 no.1
• /
• pp.160-167
• /
• 2002

Stretch fabrics are wide-spread for high performance clothing use with requirements of fitness and adaptability to human's movement. A newly developed 100% PET high stretch fabric has excellent properties with respect to stretch, softness, bulkiness, and apparent volume compared to PET filament fabrics. The 100% PET high stretch fabric shows advantages of a dimensional stability, dye and agent adaptability in dying and finishing process, a property of stretch recovery after washing and lower production cost than that of spandex fabric. KES-FB was used to measure mechanical properties to various directions of the fabric. This study centered on whether the 100% PET high stretch fabric is suitable to quality and shape retention of fabric by testing several properties including tensile, compression, shear, bending and surface characteristic to various measuring directions. Tensile linearity showed maximum value at $0^{\circ}$ in plain and $90^{\circ}$ in twill. Shear Stiffness of plain and twill showed maximum value equally at $45^{\circ}\;and\;135^{\circ}$. Bending rigidity showed maximum value at $0^{\circ}$ in plain and $45^{\circ}$ twill. Mean deviation of MIU showed maximum value at $0^{\circ}\;and\;90^{\circ}$ in plain and $135^{\circ}$ in twill.

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.3
• /
• pp.81-85
• /
• 2015

Acute sprain of the ankle requires comprehensive history taking and physical examination in diagnosing the type of severity and deciding on the plan of treatment. Literature supports functional treatment as the treatment of choice for grade I and II injuries. During the acute phase, the goal of treatment focuses on controlling pain and swelling. PRICE (protection, rest, ice, compression, and elevation) is a well-established protocol at this phase. There is some evidence that application of ice and use of nonsteroidal anti-inflammatory drugs improves healing and speeds recovery. Then the functional treatment (motion restoration and strengthening exercises) is administered to progress the rehabilitation appropriately in order to facilitate healing and restore the mechanical strength and proprioception. Early mobilization has been shown to result in more rapid return to work and daily activities than immobilization. Grade III injuries still generate controversy in terms of the best management available, and more studies on early mobilization, cast immobilization, or surgery are needed. Even the Cochrane reviews published to date are not conclusive.