• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.3
• /
• pp.459-469
• /
• 2023

The number of IoT devices is explosively increasing due to the development of embedded equipment and computer networks. As a result, cyber threats to IoT are increasing, and currently, malicious codes are being distributed and infected to IoT devices and exploited for DDoS. Currently, IoT devices that are the target of such an attack have various installation environments and have limited resources. In addition, IoT devices have a characteristic that once set up, the owner does not care about management. Because of this, IoT devices are becoming a blind spot for management that is easily infected with malicious codes. Because of these difficulties, the threat of malicious codes always exists in IoT devices, and when they are infected, responses are not properly made. In this paper, we will design an malware detection system for IoT in consideration of the characteristics of the IoT environment and present detection rules suitable for use in the system. Using this system, it will be possible to construct an IoT malware detection system inexpensively and efficiently without changing the structure of IoT devices that are already installed and exposed to cyber threats.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.31 no.2
• /
• pp.86-95
• /
• 2015

Purpose: The aim of the study was to evaluate the subjective symptoms and clinical signs through the TMD-questionnaire, clinical examination and radiography against the many instrumental performers and to investigate the association between playing instruments and TMDs. Materials and Methods: A total of 803 instrumental performers received TMD-related questionnaire and evaluations of prevalence and disease distribution were performed. Among those who reported at least one symptom of TMD, 70 volunteers visited in clinic then received clinical examination and radiography for diagnosis and evaluations of prevalence and disease distribution were performed. 70 subjects were divided into three groups as woodwind, brass wind, string. Comparative analysis of disease distribution was performed. Results: Among 803 instrumental performers, 610 people (75.97%) were reported to one or more symptoms of TMD. The most frequent symptom was click (29.68%).70 subjects underwent a clinical examination and radiography survey results, the most frequent symptom was a click (29.75%). Most commonly diagnosed disease was a myofacial pain (30.53%).Comparison of the three groups, a significant difference was not observed in the clinical sign. But among subject symptom, muscle pains howed significant differences in accordance with the Group (P = 0.024). During the 70 people who underwent clinical examination, 66 people (94.3%) showed moderate to severe attrition, mild to severe tongue ridging, mild to severe cheek ridging assigns of parafunction. Conclusion: Instrumental performers showed a high prevalence of TMD and the most of the musicians with temporomandibular disorder had bruxism or clenching habits.

• International Journal of High-Rise Buildings
• /
• v.6 no.3
• /
• pp.227-235
• /
• 2017

This paper describes some of the challenges for structural design of a mid-story seismic isolated high-rise building, which is located near Tokyo station, completed in 2015. The building is a mixed-use complex and encompasses three volumes: one substructure including basement and lower floors, and a pair of seismic isolated superstructures on the substructure. One is a 136.5m high Main Tower (office use), and the other is a 98.5 m high South Tower (hotel use). The seismic isolation systems are arranged in the $3^{rd}$ floor of the Main Tower and $5^{th}$ floor of the South Tower, so that we call this isolation system as the mid-story seismic isolation. The primary goal of the structural design of this building was to secure high seismic safety against the largest earthquake expected in Tokyo. We adopted optimal seismic isolation equipment simulated by dynamic analysis to minimize building damage. On the other hand, wind-induced vibration of a seismic isolated high-rise building tends to be excited. To reduce the vibration, the following strategies were adopted respectively. In the Main Tower with a large wind receiving area, we adopted a mechanism that locks oil dampers at the isolation level during strong wind. In the South Tower, two tuned mass dampers (TMDs) are installed at the top of the building to control the vibration. In addition, our paper will also report the building performance evaluated for wind and seismic observation after completion of the building. In 2016, an earthquake of seismic intensity 3 (JMA scale) occurred twice in Tokyo. The acceleration reduction rate of the seismic isolation level due to these earthquakes was approximately 30 to 60%. These are also verified by dynamic analysis using observed acceleration data. Also, in April 2016, a strong wind exceeding the speed of 25m/s occurred in Tokyo. On the basis of the record at the strong wind, we confirmed that the locking mechanism of oil damper worked as designed.

• Physical Therapy Korea
• /
• v.27 no.2
• /
• pp.102-110
• /
• 2020

Background: There is an opinion that improper postures of the head and cervical spine are associated with temporomandibular joint (TMJ) disorders (TMDs). Objects: The aim of this study was to investigate the proportions among the cervical kyphotic angle, physical symptoms including the pain intensity level of the TMJ, and severity of TMD disability in patients diagnosed with TMD. Methods: Sixty-two subjects participated in the study. The evaluation tools included measurements of the cervical kyphotic angle based on the Ishihara index, pressure pain threshold (PPT) on the TMJ, maximal mouth opening (MMO) without pain, current pain intensity level of the TMJ measured using the Quadruple Visual Analogue Scale (QVAS), Korean TMD (KTMD) disability index, KTMD Symptom Frequency/Intensity Scales (SFS/SIS), and Korean Headache Impact Test-6. Correlation analysis was conducted to investigate the correlations between the cervical kyphotic angle and parameters related to TMJ symptoms. Results: Variables that were significantly correlated with the cervical kyphotic angle were the PPT around the TMJ (r = 0.259, p < 0.05), current pain intensity level of the TMJ based on the QVAS (r = -0.601, p< 0.01), and usual pain intensity level based on the SIS (r = -0.379, p < 0.01). The level of TMD functional disability was significantly correlated with the degree of headache (r = 0.551, p < 0.01), level of PPT of the TMJ (r = -0.383, p < 0.01), pain-free MMO (r = -0.515, p < 0.01), pain intensity level of the TMJ based on the QVAS (r = 0.393, p < 0.01), TMD symptom frequency (r = 0.739, p < 0.01), usual pain intensity of the TMJ (r = 0.624, p < 0.01), and most severe pain intensity of the TMJ (r = 0.757, p < 0.01). Conclusion: There is a positive correlation between the cervical kyphotic angle and PPT and a negative correlation between the current and usual pain intensity levels of the TMJ. The cervical kyphotic angle was a predictor of the pain level, tenderness threshold, and intensity of pain in the TMJ.

• The Journal of Korean Academy of Prosthodontics
• /
• v.35 no.1
• /
• pp.15-29
• /
• 1997

The author performed this study to investige the relationship between condylar movements recorded with Pantronic and mandibular movements at incisal area recorded with BioEGN. For this study 24 patients with Temporomandibular disorders(TMDs) and 30 dental students without any masticatory symptoms were selected as patients group and control group, respectively. The items recorded with Pantronic(Denar Corp., USA) were immediate side-shift, orbiting path, protrusive path, and PRI. BioEGN(Bioelectric-gnathography, Bioresearch Inc., USA) were sued to measure the amount of mandibular torque movement in frontal and horizontal plane and also the distance of mandibular translation at incisal area. Amount of mandibular rotational torque movement was analyzed by angle and difference between both condyles in frontal and horizontal plane. The collected data were processed with SAS program and conclusion were as follows : 1. Mean value of items recorded with Pantronic were not significantly differed between patients group and control group except the item of pantographic reproducibility index(PRI). The value of PRI was 39.5 in patients group, and 29.5 in control group. 2. The amount of mandibular torque movement was not differed tin early protrusive and early left excursion between patients group and control group, but in early right excursion, patients group showed more value than control group did. 3. The distance on sagittal plane in early eccentric movements were longer in patients group than those in control group, but the distance of maximal eccentric movements were not significantly differed between patients group and control group. 4. Items which showed significant correlation with PRI were progressive side-shift, and horizontal torque movement in early protrusion and right excursion. 5. The angle of protrusive path of affected side was greater than of non-affected side in unilaterally affected patients, but the protrusive angle of preferred chewing side was not differed from that of contralateral side in control group. 6. The amount of torque movement in early protrusion and right excursion were greater in patients with coincidence of affected side and preferred chewing side than in patients without coincidence.

• Journal of Oral Medicine and Pain
• /
• v.41 no.4
• /
• pp.161-168
• /
• 2016

Purpose: Patients who suffer from rheumatic arthritis, fibromyalgia, other various inflammatory diseases and musculoskeletal disorders, which are all similar to temporomandibular disorders (TMD), have been complaining about changes in the level and type of pain in response to changes in weather conditions for a long time. Through an investigation about pain perception in TMD patients in response to weather conditions, our primary objective was to develop base materials for future studies on change in pain in response to meteorological factors. Methods: Among patients who presented with TMD to Department of Oral Medicine, Pusan National University Dental Hospital from August to October 2016, one hundred consecutive TMD patients diagnosed with TMDs according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were recruited for the study and 28 patients were excluded according to exclusion criteria. Survey was done with the questionnaire and investigated whether there was any difference in incidence and level of pain in TMD patients between non-rainy and rainy days. Results: Among a total of 72 samples, 4 patients reported change in pain on rainy days rather than non-rainy days. Two patients from chronic group (joint and complex subgroup) reported increased pain on rainy days rather than non-rainy days but it was not statistically significant (p>0.05). One patient from chronic/muscle group reported the change in pain characteristics while pain intensity remained unchanged. One patient from acute/complex group reported decreased pain intensity. In comparison of the patients who reported increased pain on rainy days between acute and chronic groups, there were two reported cases and were both from chronic group only. There was a significantly higher chance of reporting increased pain on rainy days in chronic group than acute group (p<0.001). Conclusions: It is considered that TMD patients couldn't perceive the change in pain well in response to weather change on rainy days but some chronic patients could perceive the increase in pain in rainy days.

• Journal of Oral Medicine and Pain
• /
• v.38 no.1
• /
• pp.87-95
• /
• 2013

Osteoarthritis (OA) of the temporomandibular joint (TMJ) is a severe form of temporomandibular disorders (TMDs), presenting gradual breakdown of articular cartilage and subchondral bone by the functional load sustained to exceed the physiologic tolerance of the joint. In such a joint loaded, offensive bioactive materials such as matrix degrading proteins, cytokines, and free radicals increase in concentration to shift the tissue response in the joint to degeneration from regeneration or remodeling. Recently, it has been issued that obesity can play an offensive role in pathogenesis of OA in a metabolic way. Adipokines released by adipose cells are present at higher concentration in the arthritic joint and joints of obese individuals. However, because of conflicting data reported, further scientific study should be performed to elucidate the practical role of adipokines in pathogenesis of TMJ OA. As far as the clinical signs and symptoms of TMJ OA are not much different from those of other forms of TMD and any definitive treatment modality to control directly the bone resorptive activity is not available yet, the treatment of TMJ OA should be directed to reduce the physical load and enhance the physiologic tolerance of the joint by means of conservative treatment such as physical therapy, medication, and occlusal splint therapy for sufficient period and, if needed after that, supplementary surgical procedure such as intra-articular injection, arthrocenthesis, and arthroscopic surgery that have turned out to be effective to control OA signs and symtpoms. Enthusiastic reassurance and motivation for patients to control behaviors for themselves to reduce unnecessary functional load in daily life is very important for the joint to reach to more favorable orthopedic stability of the TMJ more quickly, guaranteeing more successful management TMJ OA.

• Journal of Oral Medicine and Pain
• /
• v.26 no.1
• /
• pp.59-73
• /
• 2001

This study was performed to investigate the effects of occlusal appliance on the mandibular position and the mandibular rotational torque movement during speech. For this study, 20 patients with temporomandibular disorders(TMDs) and 20 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) and a sentence of 'Sue is missing her house' were used for recording and for observing of speech pattern. There were five mandibular positions observed in this study, that is, mandibular rest position, 'ssi', 'her', 'ha', and 's' speech position. In each position, slant and A-P distance in sagittal plane, vertical distance and lateral distance in frontal plane were measured. Amount of the mandibular rotational torque movement were measured at 'her', 'ha' speech position and for all through speech movement. Centric relation splint(CRS) was placed in both groups, but anterior or posterior bite plane were placed in normal subjects only. Data collected were processed and analysed by SPSS windows program. The results of this study were as follows : 1. Mandibular positions in both groups were not different before adaptation, with CRS, and after removal, but total amount of the mandibular rotational torque movement was greater in patients. 2. Mandible was slightly placed anteriorly with CRS at 'her' and 'ha' speech position in patients, but was placed anteriorly at all the five positions in normal subjects. 3. Difference with type of occlusal appliance in normal subjects were noted only for vertical distance at 'ssi' and 'ha' speech position, and the distance with CRS were more than that with posterior bite plane. 4. Mandibular rotational torque movement at 'her' and 'ha' speech position was greater in patients, but the difference was disappeared after appliance removal. And the torque movement was greater at 'ha' speech position than that at 'her' speech position in frontal plane. It could be concluded that the adaptation of occlusal appliance showed a tendency to locate the mandible anteriorly during speech in both groups, but did not affect total mandibular rotational torque movement which was greater in patients.

• Journal of Oral Medicine and Pain
• /
• v.25 no.2
• /
• pp.191-203
• /
• 2000

This study was performed to investigate the relationship between vertical dimension during swallowing and speech pattern in patients with temporomandibular disorders. For this study, 33 patients with temporomandibular disorders(TMDs), namely, 17 patients with disc displacement with reduction and 16 patients with disc displacement without reduction, and 30 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) was used for recording of electromyographic(EMG) activity(${\mu}V$) of the anterior temporalis, the superficial masseter, the sternocleidomastoideus and the trapezius insertion muscle during swallowing, and of mandibular positional change with function time(sec.) during swallowing and speech. A sentence of 'Sue is missing her house' was used for observing of speech pattern. Comparison between the two groups and relationship of the mandibular positional change and the function time between during swallowing and during speech were analysed by SPSS windows program. The results of this study were as follows : 1. Mean EMG activity of the trapezius insertion during swallowing was higher in the patient group, and the value was $3.4{\mu}V$ in patients and $2.1{\mu}V$ in normal subjects. 2. Vertica1 dimension(VD) at mandibular rest position before swallowing was slightly higher in the patient group, but VD at swallowing-late stage and at rest position after swallowing were not different between the two groups. 3. Swallowing time were 2.1 sec. in the patient group, and 1.5 sec. in the normal group, and the difference was significant. 4. VD during speech were generally higher in the normal group. In this case, speaking position showing the most difference between the two groups was 'her' position. The distance from habitual intercuspal position to 'her' position was 4.9mm in the patient group, and 6.6mm in the normal group. Speaking time was also longer in the patient group. 5. There were no difference in all observed items between the two categories of the patient group according to reduction of disc displacement. 6. Relationship between the positional changes during swallowing and speech were different between the patient group and the normal group. And in the normal group, VD at rest position before swallowing was negatively correlated with speaking time.

• Journal of Adhesion and Interface
• /
• v.22 no.2
• /
• pp.57-62
• /
• 2021

Recently, the atomically thin two-dimensional transition-metal dichalcogenides (TMDs) have received considerable attention for the application to next-generation semiconducting devices, owing to their remarkable properties including high carrier mobility. However, while a technique for growing graphene is well matured enough to achieve a wafer-scale single crystalline monolayer film, the large-area growth of high quality TMD monolayer is still a challenging issue for industrial application. In order to enlarge the size of single crystalline MoS₂ monolayer, here, we systematically investigated the effect of process parameters in molten-salt-assisted chemical vapor deposition method. As a result, with optimized process parameters, we found that single crystalline monolayer MoS₂ can be grown as large as 420 ㎛.