• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.10a
• /
• pp.270-271
• /
• 2014

In spite of the methodology of evacuation process on vessels should be different comparing to the architecture on land, some have simulated the evacuations onboard ship with simulation tools which is developed only for the architecture. On this study, a vessel-oriented simulation tool is used to analyze the possibility of evacuation for a passenger ship. ${\cdots}$(중략)${\cdots}$ As a result of the simulation analysis, it is clear that the initial responding time and start-to-move time are so important, ${\cdots}$(중략)${\cdots}$.

• IE interfaces
• /
• v.9 no.3
• /
• pp.64-71
• /
• 1996

In the survivability and simplicity aspect, SONET Self-healing Ring(SHR) is one of the most important schemes for the high-speed telecommunication networks. Since the ring capacity requirement is defined by the largest STS-1 cross-section in the ring, load balancing is the key issue in the design of SONET SHR. Recently, most of the research on load balancing problem have been concentrated on the SONET single-ring case. However, in certain applications, multiple-ring configuration is necessary because of the geographical limitations or the need for extra bandwidth. In this paper, the load balancing problem for SONET dual-ring is considered by assuming symmetric inter-ring demands. We present a linear programming based formulation of the problem. Initial solution and improvement procedures are presented, which solves the routing and interconnection between the two rings for each demand. Computational experiments are performed on various size of networks with randomly generated demand sets. Results show that the proposed algorithm is excellent in both the solution quality and the computational time requirement. The average error bound of the solutions obtained is 0.26% of the optimum.

• Journal of Trauma and Injury
• /
• v.33 no.4
• /
• pp.275-278
• /
• 2020

A 24-year-old man presented to King Saud Medical City emergency department with a retained bullet in his penis following a civilian exchange of gunfire. After an initial assessment, the patient was taken to the operating room. Penile exploration was performed, the bullet was extracted successfully, and the corpora cavernosa were repaired properly. A 6-week follow-up showed full healing with preservation of erectile function. Immediate surgical intervention is mandatory as the primary treatment for penile gunshot injury to ensure proper anatomical and functional recovery.

• Korean Journal of Materials Research
• /
• v.33 no.11
• /
• pp.458-464
• /
• 2023

In order to develop catechin patches for skin regeneration at wound sites, patches with varying concentrations of catechin and chitosan were manufactured. An optimal composition ratio was determined by adjusting the drug release rate and amount, to maximize efficiency. The catechin used in this study was extracted from green tea leaves using a solvent/ultrasonication method, and its characteristics were confirmed through Fourier transform-infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) analyses. Patches were prepared with different concentrations of catechin and chitosan, and various properties were analyzed using techniques such as FT-IR, water contact angle analysis, and UV-Vis spectroscopy. It was observed that as the chitosan concentration increased, the release of catechin slowed down or almost ceased. A patch manufactured with 1.5 mg/cm² of catechin at a 1 % chitosan concentration exhibited a high initial release rate over 24 h and demonstrated cellular biocompatibility. Consequently, these patches, with tailored release characteristics based on the concentrations of chitosan and catechin, hold promise for use as drug delivery systems in wound healing applications.

• Journal of Veterinary Clinics
• /
• v.25 no.5
• /
• pp.379-384
• /
• 2008

The objective of this study was to determine output power for skin incision in 0.3 mm spot diameter $CO_2$ laser by measuring (1) the wound depth, (2) initial dermal tissue damage, (3) degree of wound healing at different power (4W, 5W and 6W) in beagle dogs. Three healthy 2-year-old beagle dogs were used. Four 2 cm straight skin incisions were made with 0.3 mm spot diameter $CO_2$ laser on the each dog's both side of dorsal midline in three beagle dogs. The skin incisions were performed for $10{\sim}15$ seconds for same dosage. And then each wound was closed with surgical stapler. At 0, 3, 7 and 14 days after initial wounding, each wound was taken for histological observation. On macroscopic and microscopic observation, initial incisional wound did not show difference in three group. And also re-epithelialization, dermal tissue damage and inflammatory response did not show significant difference among groups. This study reveals that 4W, 5W and 6W may be suitable output power in 0.3 mm spot diameter $CO_2$ laser for the skin incision in beagle dogs.

• Journal of Periodontal and Implant Science
• /
• v.37 no.4
• /
• pp.681-690
• /
• 2007

Mini implants had been used provisionally for the healing period of implants in the beginning. But it becomes used for the on-going purpose, because it is simple to use, economic and especially suitable for the overdenture. But there is few studies about the stability of mini implants, that is most important factor for the on-going purpose, and particularly the implant parameters affecting the initial stability. The purpose of this study was to evaluate the stress and the strain distribution pattern of immediate-loaded screw type orthodontic mini-implant and the parameters affecting the initial stability of immediate-loaded mini-implant. Two dimensional finite element models were made and contact non-linear finite element analysis was performed. The magnitude and distribution of Von Mises stresses were evaluated. The obtained results were as follows: 1. The stress was concentrated on the thread tip of an implant in the cortical bone. 2. The direction of load is the most important factor for the stress distribution in cortical bone. 3. The diameter of an implant is the most important factor for the stress distribution in the trabecular bone. In conclusion, if the horizontal load vector is successfully controlled, mini-implants, which diameter is under 3mm, can be used for the on-going purpose.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.12 no.1
• /
• pp.14-26
• /
• 1990

This study was undertaken to observe the histopathologic changes of the extraction wounds of diabetic rats when exposed to hyperbaric oxygen. A total of 50 rats (Spraque-Dawley strain) were used, which were all induced with diabetes using streptozotocin before the experiment. The experimental group was exposed to hyperbaric oxygen at 2.5atm. for 2 hours a day during the experimental period. The obtained results were summarized as follows : 1. Severe infiltration of inflammatory cells was observed in the initial stages of both the control and experimental groups. The infiltration showed a decreasing tendency at 3rd week in the experimental group, while severe inflammatory infiltration observed in the control group during the entire experimental period. 2. There was abundant proliferation of capillary blood vessels at 1st week after extraction in the experimental group, while moderate capillary growth in the control group was observed at 1st week after extraction. 3. Osteoblastic activity was started at 1st week after extraction in the experimental group, but there showed markedly delayed appearance in the control group, which showed at 2nd week after extraction. 4. The proliferation of fibroblasts showed rather in the experimental group at 1st week, but it was moderate in the control group at 1st week, 2nd week and 3rd week. 5. Epithelialization of the extraction wound was started at 2 days after extraction and reached its peak at 3rd week in the experimental group, while control group seemed to be delayed and incompleted during the experiment. With regard to these results, hyperbaric oxygen therapy disclosed an effective results on the healing of the extraction wound in diabetic rats under exposure at 2.5 atm for 2 hours daily.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.12 no.1
• /
• pp.1-13
• /
• 1990

The main objectives of this study was to observe the effects of hyperbaric oxygen therapy on the healing processes of mandibular fracture of streptozotocin-induced diabetic rats. Author used 60 rats (Sprague-Dawley Strain) deviding into control(30) and experimental groups(30). Complete fracture was produced on the left mandibular body of 60rats, rendered hyperbaric oxygen therapy (2 hrs. daily at 2.5 atm.) on experimental group and observed effects of hyperbaric oxygen therapy by microscopically. The obtained results were as follows; 1. Infiltration of inflammatory cells was no significant differences between the control and experimental group until 3rd week, but experimental group showed decreasing tendency after 4th week. 2. Severe proliferation of fibroblasts showed rather rapider in experimental group, at 2nd week, while at 3rd week in control group. 3. Osteoclasts appeared at 1st week in experimental group while at 3rd week in control group, and experimental group showed early bone resorption pattern. 4. Osteoblasts appeared at 1st week in experimental group while at 3rd week in control group, and experimental group showed prominent osteoblastic activity. 5. Moderate proliferation of capillary blood vessels showed in initial stage of experimental group while mild proliferation at 1-2nd week in control group. 6. Formation of cartilaginous callus showed at 4th week in experimental group, while at 6th week in control group. 7. Formation of bony callus showed mildly at 5th week, and moderately at 6th week in experimental group, while no appearance in control group, but complete bony union was not observed even in experimental group throughout this experiment.

• Archives of Plastic Surgery
• /
• v.41 no.6
• /
• pp.668-672
• /
• 2014

Background Negative-pressure wound therapy (NPWT) is believed to accelerate wound healing by altering wound microvascular blood flow. Although many studies using laser Doppler have found that NPWT increases perfusion, recent work using other modalities has demonstrated that perfusion is reduced. The purpose of this study was to investigate the influence of NPWT on tissue oxygenation of the foot, which is the most sensitive region of the body to ischemia. Methods Transcutaneous partial pressure of oxygen ($TcpO_2$) was used to determine perfusion beneath NPWT dressings of 10 healthy feet. The sensor was placed on the tarso-metatarsal area of the foot and the NPWT dressing was placed above the sensor. $TcpO_2$ was measured until it reached a steady plateau state. The readings obtained at the suction-on period were compared with the initial baseline (pre-suction) readings. Results $TcpO_2$ decreased significantly immediately after applying NPWT, but gradually increased over time until reaching a steady plateau state. The decrease in $TcpO_2$ from baseline to the steady state was 2.9 to 13.9 mm Hg (mean, $9.3{\pm}3.6$ mm Hg; $13.5{\pm}5.8%$; P<0.01). All feet reached a plateau within 20 to 65 minutes after suction was applied. Conclusions NPWT significantly decrease tissue oxygenation of the foot by 2.9 to 13.9 mm Hg. NPWT should be used with caution on feet that do not have adequate tissue oxygenation for wound healing.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.4 no.1
• /
• pp.6-11
• /
• 2005

Injury of articular cartilage can be classified into acute injury and chronic degenerative osteoarthritis Acute mechanical trauma on articular cartilage causes injuries that are divided into three distinct types based on the depth of injury: microdamage, chondral fracture, osteochondral fracture and each type has different potential of healing response and long-term prognosis. Articular cartilage undergoes degradation in response to a number of stimuli and eventually degenerative osteoarthritic changes will progress. The extent of initial injury to the articular cartilage is the most important factor affecting the long-term outcome of the healing response and other variables such as the size of lesion, site, age, activity level, obesity, limb alignment are also important factors. In this review, the pathophysiology that occurs within articular cartilage after different injuries and the effect of nonsurgical treatment mainly in physicochemical aspect and biological aspect will be discussed.