• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.374-384
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• 2008

This study examined the attitudes of the Korean forest policy interest groups toward the new environmental paradigm and resources management paradigm which were emerged in western societies. The 1st survey was conducted for five interest groups (forest owners, timber industries, members of the Korean Alpine Club, members of the Korean Natural Parks Association, forestry experts) in 1995, and the 2nd survey was conducted in 2006 for three interest groups (forest owners, members of the Forest for Life, members of the Baekdudaegan Preservation Society). The survey results show that there are significant differences in attitudes and beliefs toward the new environmental and resources management paradigms among groups. The environmental conservation groups such as the members of the Alpine Club, Nature Parks Association, Forest for Life, Baekdudaegan Preservation Society favor the NEP and NRMP more than those of traditional forestry related groups such as forest owners and timber industries. But, there are no significant attitudinal changes among forestry related groups. This research provides valuable insights into understanding the attitudinal positions of the interest groups toward forest resources management and policy formulation in Korea.

• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.237-248
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• 2008

Recently the social movement which emphasizes the new balanced relationships between human and its environment has been arisen. In the field of forestry also the new paradigm which requires to manage forest resources in a sustainable way has been issued. Furthermore forest policy environment in Korea has been rapidly changed. The Forest Law era lasted over 40 and more years was ended and the new Forest Basic Law era which emphasizes the sustainable forest management just started in 2006. Under these circumstances this study explored the attitudinal changes of the Korea Forest Service employees, who have strong influence in forest policy making and implementing, on the multiple use issues of national forests, the new environmental paradigm and resources management paradigm between 1993 and 2006. The study results indicate that there are no significant differences on attitudes and beliefs between the staff and line employee groups. But there are attitudinal changes between 1993 and 2006 groups. Generally the KFS employees favored using national forest lands for the timber production and recreational uses, but they did not favor the livestock forage and mineral development. The KFS employees have pro-environmental attitudes and beliefs. On the other hand they perceive the KFS policy position is more toward commodity production or neutral.

• The korean journal of orthodontics
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• v.38 no.2
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• pp.121-132
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• 2008

Objective: The purpose of this study was to evaluate the upper airway dimensional change according to maxillary superior movement after orthognathic surgery and to identify the relationship between the amount of maxillary movement and upper airway dimensional changes. Methods: The samples consisted of 24 adult patients (9 males and 15 females) who had a skeletal discrepancy and had received presurgical orthodontic treatment. They underwent Le Fort I superior impaction osteotomy and mandibular setback surgery. Cephalometric x-rays were taken at 3 stages - T0 (before orthognathic surgery), T1 (just or within 2 weeks after orthognathic surgery), T2 (6 months after surgery) Results: 1, Pharyngeal airway space (PAS (R)-nasopharynx) was decreased after surgery (T1) but recovered at 6 months after surgery; 2, Pharyngeal airway space (PAS (NL)-palatal plane) was increased after surgery and at 6 months after surgery; 3, Pharyngeal airway space (PAS (OL)-occlusal plane) was increased at T1 and was decreased at T2; 4, Soft palate thickness was increased at T1 but it became the same or thinner at T2; 5, There is no statistically significant relation between the amount of maxillary superior movement and pharyngeal airway space. Conclusions: These findings suggested that the maxillary superior movement of about an average of $4.40{\pm}1.14 mm$ did not affect upper pharyngeal airway space changes.

• Journal of Broadcast Engineering
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• v.25 no.1
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• pp.94-104
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• 2020

Currently media consumption over fixed/mobile Internet is mostly conducted by adaptive media streaming technology such as DASH (Dynamic Adaptive Streaming over HTTP), which is an ISO/IEC MPEG (Moving Picture Experts Group) standard, or some other technologies similar to DASH. All these heavily depend on the HTTP caches that ISPs (Internet Service Providers) are obliged to provide sufficiently to make sure fast enough Web services. As a result, as the number of media streaming users increases, ISPs' burden for HTTP cache has been greatly increased rather than CDN (Content Delivery Network) providers' server burden. Hence ISPs charge traffic cost to CDN providers to compensate for the increased cost of HTTP caches. Recently in order to reduce the traffic cost of CDN providers, P2P (Peer-to-Peer)-assisted DASH system was proposed and a peer selection algorithm that maximally reduces CDN provides' traffic cost was investigated for this system. This algorithm, however, tends to concentrate the burden upon the selected peer. This paper proposes a new peer selection algorithm that distributes the burden among multiple peers while maintaining the proper reduction level of the CDN providers' cost. Through implementation of the new algorithm in a Web-based media streaming system using WebRTC (Web Real-Time Communication) standard APIs, it demonstrates its effectiveness with experimental results.

• Journal of the military operations research society of Korea
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• v.34 no.2
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• pp.163-174
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• 2008

The military is an organization where reliability and availability take much more importance than in any other organization. And, in line with a recent trend of putting emphasis on 'system readiness', not only functions but also availability of a weapon system has become one of achievement targets. In this regard, the military keeps spares for important facility and equipment, which is called as Maintenance Float (M/F), in order to enhance reliability and availability in case of an unforeseen event. The military has calculated yearly M/F requirements based on the number of equipment and utilization rate. However, this method of calculation has failed to meet the intended targets of reliability and availability due to lack of consideration on the characteristics of equipment malfunctions and maintenance unit's capability. In this research, we present an analysis model that can be used to determine an optimal M/F inventory level based on queuing and absorbed Markov chain theories. And, we applied the new analysis model to come out with an optimal volume of K-1 tank M/F for the OO division, which serves as counterattack military unit. In our view, this research is valuable because, while using more tractable methodology compared to previous research, we present a new analysis model that can describe decision making process on M/F level more satisfactorily.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.868-873
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• 1997

Nitrifier consortium entrapped in Ca and Ba-alginate beads were packed into two reactors and studied for removing ammonia-nitrogen in aquaculture system. The ammonia-nitrogen concentration of the influent was continually kept about 2 ppm. At the hydraulic residence time of 0.6 hours, ammonia-nitrogen removal amount of two reactors was about 52.6 and 51.0 g $NH_3-N/m^3/day$, respectively. The ability of adjusting to an impulsive leading which was happened according to variations of HRT was better at Ba-alginate reactor, but its discrepancy was not so large. At the respect of removing ammonium-nitrogen, two reactors showed the similar ability of treating recirculating water.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.17-25
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• 2017

Horizon scanning that one of the methods for future prediction is adaptable way of establishing the policy strategy based on big data. This study aims to understand the social problems scientifically utilized horizon scanning technique, and contribute to public policy formulation based on scanning analysis. In this paper, we proposed a public opinion framework for public policy based on social bigdata, and then confirmed the feasibility this framework by analysis of the relationship between public opinion and results after implementation of public policy. Consequently, based on the analysis, we also drew implications of policy formulation about 'free childcare for under 5-years of age' as an object of study. The method that collects public opinion is very important to effective policy establishment and make contribution to constructing national response systems for social development.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.298-304
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• 2007

Purpose: This study was undertaken to investigate the osteogenic induction potential of PGA & FBS mixture on a calvarial defect in the rabbit. Methods: Twenty New zealand white rabbit, weighing from 3.5-4kg were allocated into each of the three groups. Four 8 mm sized bone defects were made on the parietal bone by drilling. In group I, the bony defects were implanted with $50{\mu}m$ thickness film containing mixture of PGA and FBS. In group II, with PGA only film, & in group III, the bony defects were left with no implants. Results were evaluated by using morphologic change, radiographic study, biochemical study and histologic examination at 1 week (group I n=7, group II n=7, group III n=14), 2 weeks (group I n=6, group II n=6, group III n=12) and 3 weeks (group I n=7, group II n=7, group III n=14) following implantation. Results: In the morphologic & radiographic study, the formation and corticalization of callus were observed earlier in group I than in groups II and III (p < 0.05). In histological examination, group I showed more abundant and faster new bone formation than in group II and III. In biochemical analysis, group I displayed more activity than in group II and III. Group I also showed more abundant osteopontin, osteocalcin than groups II and III. Conclusion: In conclusion, the results demonstrate that the mixture of PGA and FBS has an effect on osteoblastic formation in the rabbit model. It is considered that further evaluation of long term results on resorption, immunologic tissue reaction and response of applied mixture in the human model will be needed.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.365-370
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• 2007

Purpose: There are many reports about facial bone fractures, but limited to retrospective data of a single hospital. Etiology and severity of the facial bone fracture have been changed and treatment method and materials have been advanced. In order to reflect those changes and provide up-to-date data of the facial bone fractures in Daegu, we gathered the data and analyzed the epidemiologic study. Methods: The medical records of 1058 fractures in 895 patients were gathered from 5 general hospitals in Daegu during last year and these data were analyzed by following parameters: age, sex, place of residence, occupation, cause of injury, time of injury, location of fracture, length of in-hospital stay, time of operation, treatment method, associated injury, complication. Statistical analysis was performed using the Chi-square test. Results: Most commonly involved age group was 20s(26%) and the sex ratio was 3.4:1(male predominance). Fractures were occurred more in unban and white-color workers. Among variable etiology of injury, traffic accident was the most common cause. Time of injury was heighest at 6 to 7 P.M., on Sunday, in July. Locations of fractures were following sequence: nasal, zygoma, mandible, orbit, maxilla. Mean length of in-hospital stay and time of operation after injury were 6.3 and 3.2 days, respectively. In treatment methods, operative methods were dominant than conservative management and general anesthesia were favored than local anesthesia. Associated injuries were noticed in 188 cases(21.2%) and complications were in 94 cases(8.9%) and among them, ocular problem were common. Conclusion: Compared to previous studies, mean age of occurrence was lowered and the etiologies showed age-specific pattern and reflected the change of lifestyle. In young age groups, sports injury, violence were more dominant and the other hand, traffic accident and fall were dominant in older groups.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.469-474
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• 2009

Purpose: A lower facial contouring surgery has become a commonly performed procedure in Asia. Currently, mandibular angle sagittal ostectomy and botulinum toxin type A treatment are main procedures for aesthetic correction of a broad lower face. There are a few date to show the differences in the mandibular contouring changes between mandibular angle splitting ostectomy and botulinum toxin type A treatment. Facial golden mask is easy to apply, inexpensive, and relatively objective for evaluation of facial contour analysis. This study was designed specifically to compare the changes in lower face width after two different forms of lower facial contouring procedure using facial golden mask. Methods: Seventeen patients, aged 18 to 55 years (mean, 28.6 years), 15 women and 2 men, consented to the study and receive a contouring procedure of lower face. The patients were classified in to 2 groups. In group A, the sample consisted of 10 patients with a prominent squared mandibular angle and mandibular angle splitting ostectomy was performed. In group B, the sample consisted of 7 patients with masseteric hypertrophy and botulinum toxin type A treatment was performed. Photographs of the face were taken to record the facial change at preoperative and postoperative. The postoperative photographs were taken to considered maximal effect at 2 years after surgery in group A and 4.8 months after treatment in group B. The authors applied the facial golden mask to preoperative and postoperative photographs and horizontal ratio, which compares facial width with golden mask width, were calculated. We made an analysis of the result of horizontal ratio using SPSS. Results: Overall average horizontal ratio of pre- and postoperative photos of group A were 1.24 and 1.11, whereas overall average horizontal ratio of pre- and postoperative photos of group B were 1.19 and 1.12. The horizontal ratio decreased 10.24% in group A and 5.93% in group B. There was a statistically significant change in before and after treatment, but there was no significant change in comparing the group A and group B. Conclusions: The result from this study suggest that mandibular angle sagittal ostectomy and botulinum toxin type A treatment showed relatively satisfactory clinical effects on lower facial contouring treatment. There was no statistical significant difference within two lower facial contouring treatment. Facial golden mask is easy to apply, inexpensive, and relatively objective, so we think that facial golden mask is a good method for evaluation of lower facial contouring treatment.