• Journal of Internet Computing and Services
• /
• v.15 no.1
• /
• pp.73-88
• /
• 2014

Online communities are getting more popular with the development of information technology. It is essential that community members participate actively and share their contents or opinions continuously for the success and growth of online communities. However, it is revealed that most of members just take the role of passive observer. They are lurking community information and contents without any contribution. In this sense, this study focuses on explore lurking behavior of online community members. This study investigates the effect of the characteristics of online community, community members, and personal traits on user's lurking intention. Member familiarity and community identity have a strong positive effect on de-lurking intention, while the perception of usefulness and ease of use for communities and member expertise have a negative effect on de-lurking intention. Interestingly, users with a low level of self-esteem have higher level of motivation of participation than those with a high level of self-esteem. Finally, this study proposes several strategies to enhance information and contents sharing in online communities.

• Tuberculosis and Respiratory Diseases
• /
• v.62 no.1
• /
• pp.5-10
• /
• 2007

Background: Korean national guidelines for examining contacts with active pulmonary tuberculosis (TB) are a tuberculin skin test (TST) and chest radiographs. The treatment of a latent TB infection as performed only in those younger than six years of age who test positive for TST. Although there is a high incidence of active TB in young Korean soldiers, the current national guidelines for controlling contacts with active TB in soldiers are insufficient. This study highlights the problems with the Korean guidelines for controlling a TB outbreak in a small military unit. Material and Methods: In December of 2005, there was a tuberculosis outbreak in a military unit with a total of 464 soldiers in Kyung Gi province. The chest radiographs were taken of all the soldiers, and TST were carried out on 408 candidates. Results: In the first screening of the chest radiographs, two active TB patients were detected. By August of 2006, four additional cases were detected, making a total of six cases after the outbreak. All the patients showed active pulmonary TB or TB pleuritis. When the results of TST in the close contacts and non-close contacts were compared, there was a significant difference in the absolute size of the induration($9.70{\pm}7.50mm$ vs. $6.26{\pm}7.02mm$, p<0.001) as well as the ratio of patients showing an induration > 10mm (50.0% vs. 32.0%, p<0.001) and 15mm (33.2% vs. 20.9%, p= 0.005). Conclusion: Although the national guidelines for managing a TB outbreak in a military unit were followed, there were continuous instances of new active TB cases. This highlights the need for new guidelines to prevent the spread of TB.

• Sleep Medicine and Psychophysiology
• /
• v.18 no.1
• /
• pp.40-44
• /
• 2011

Narcolepsy is a sleep disorder, which is characterized by excessive daytime sleepiness (EDS) that is typically associated with cataplexy, sleep fragmentation and other REM sleep-related phenomenon such as sleep paralysis and hypnagogic hallucination. Narcoleptic symptoms can be developed from various medical or neurological disorders. A 17-year-old male patient admitted for the evaluation of EDS which started three-month ago. He slept more than 18 hours a day with cataplexy and hypnagogic hallucination. He was obese with body mass index (BMI) of 30.4 kg/$m^2$. After admission he was newly diagnosed to the thyrotoxicosis. T3 391.2 ng/dL (60-181), free T4 4.38 ng/dL (0.89-1.76), TSH <0.01 ${\mu}IU$/mL (0.35-5.5) were measured. His pulse rate ranged 70-90 beats per minute and blood pressure ranged 150/100-120/70 mmHg. Polysomnography revealed many fragmentations in sleep with many positional changes (81 times/h). Sleep onset latency was 33.5 min, sleep efficiency was 47.9%, and REM latency from sleep onset was delayed to 153.6 min. REM sleep percent was increased to 27.1%. Periodic limb movement index was 13.4/h. In the multiple sleep latency test (MSLT), average sleep latency was 0.4 min and there were noted 3 SOREMPs (Sleep Onset REM sleep period) on 5 trials. We couldn't discriminate the obvious sleep-wake pattern in the actigraph and his HLA DQB1 $^*0602$ type was negative. His thyroid function improved following treatment with methimazole and propranolol. Vital sign maintained within normal range. Cataplexy was controlled with venlafaxine 75 mg. Subjective night sleep continuity and PLMS were improved with clonazepam 0.5 mg, but the EDS were partially improved with modafinil 200-400 mg. Thyrotoxicosis might give confounding role when we were evaluating the EDS, though sleep fragmentation was one of the major symptoms of narcolepsy, but enormous amount of it made us think of the influence of thyroid hormone. The loss of sleep-wake cycle, limited improvement of EDS to the stimulant treatmen, and the cataplexy not supported by HLA DQB1 $^*0602$ should be answered further. We still should rule out idiopathic hypersomnia and measuring CSF hypocretin level would be helpful.

• Sleep Medicine and Psychophysiology
• /
• v.14 no.2
• /
• pp.92-98
• /
• 2007

Objectives: Obstructive sleep apnea syndrome (OSAS) is the most common form of sleep-disordered breathing and often presents with comorbid depressive symptoms. In this study, we evaluated the relationship between depressive symptoms and sleep parameters as measured by nocturnal polysomnography (NPSG) and simultaneous wrist actigraphy. Methods: Two hundred sixty-four subjects with clinically suspected cases of OSAS underwent one-night polysomnography, while simultaneously wearing a wrist actigraphy device. They also completed two questionnaires；the Epworth Sleepiness Scale-Korean version (ESS-K) and the Beck Depression Inventory (BDI). Of the cases studied, 105 subjects were proven by NSPG to have OSAS without other sleep disorders. NPSG and wrist actigraphy data from the subjects were analyzed. Pearson correlation and paired t-test were used in order to evaluate the relationship between depressive symptoms and sleep-parameters. Results: Mean age of the subjects was $46.1{\pm}13.1$ years. Means of the ESS-K score and BDI scores were $10.9{\pm}4.7$ and $12.8{\pm}8.1$, respectively. NPSG sleep parameters significantly differed from those of wrist actigraphy. There was no correlation found between subjects' respiratory disturbance index (RDI) and BDI scores. When directly comparing sleep parameters between subjects who were more depressed versus subjects who were less depressed, both total sleep time and sleep efficiency were decreased in the more depressed. A correlation between RDI and ESS-K scores was also found in the more depressed group. Conclusions: Although our findings suggest that there is no relationship between RDI and depressive symptoms, there are other significant differences in the sleep parameters between subjects who are more depressed versus those without depression. We recommend that patients with depression should also be evaluated for clinical symptoms of OSAS.

• Journal of Chest Surgery
• /
• v.32 no.4
• /
• pp.383-387
• /
• 1999

Background: We analysed simple chest PA and high-resolution CT findings in patients with spontaneous pneumothorax in order to help selecting the kind of treatment, provide a guidline during surgical treatment, and to recognize the bulla which may not be detected by simple radiographs or may be a potential cause of recurrence. Material and Method: We retrospectively analysed the presence and number of bulla in each side, combined pulmonary disease on simple chest films and high-resolution CT, and methods and frequency of the treatment in 70 patients with spontaneous pneumothorax excluing traumatic origin. Result: 45 patients were revealed primary spontaneous pneumothorax, and the remaining 25 patients were revealed secondary spontaneous pneumothorax. All secondary spontaneous pneumothorax were from the longstanding sequelle of pulmonary tuberculosis. The patients with primary spontaneous pneumothorax group was younger(mean:26.0 years old) than secondary group (mean: 44.1 years old). On simple radiography, bulla was detected in 16 patients(30.2%). On HRCT, the bulla was detected in 53 patients(75.7%) of the total 70 patients. In 48 patients(68.6%), the bulla or bleb was noted in ipsilateral side to the pneumothorax, and 34 patients(48.6%) of them showed bulla or bleb bilaterally. 39 patients(55.7%) showed bulla or bleb in contralateral side. The number of bulla or bleb was variable. In secondary spontaneous pneumothorax group, the incidence of multiple(more than 10) bulla or bleb was higher than primary type. Most of the patients were treated by thoracostomy(36 patients) or bullectomy( 7 patients). Conclusion: HRCT was superior to detect bulla and analyse the combined pulmonary disease than simple radiography. Therefore, HRCT can help to determine the mothod of treatment, provide a guidline during surgical treatment, and notify the bulla as a possible cause of recurrent pneumothorax.