Earticle

CSMA(Carrier Sense Multiple Access)는 여러 노드들이 채널을 공유하여 사용하는 경우, 노드들의 접속을 조절해 주는 기술이다. 여러 노드들이 채널을 공유하므로 발생하는 충돌 가능성을 줄이고 성능을 향상시키기 위해 채널의 사용 여부를 확인한다. 본 논문에서는 CSMA의 다양한 persistent 방법 중 네트워크 효율성과 충돌 확률의 문제점을 보완하는 p-persistent 방법을 기반으로 성능향상 방안을 연구하였다. p-persistent 방법이 네트워크 효율성과 충돌 확률의 문제점을 해소할 수는 있지만, 네트워크에 존재하는 노드 수에 따라 전송 확률 p는 성능에 큰 영향을 준다. 본 논문에서는 네트워크 환경에 따라 노드의 전송 확률을 조절하여 성능을 향상시키는 방법을 제안한다. 충돌 가능성이 적은 경우에는 p를 증가시켜 데이터의 전송을 늘리고, 충돌 가능성이 많은 경우에는 p를 감소시켜 충돌을 줄임으로 성능을 향상시킨다. 본 논문에서는 제안한 동적 CSMA 다중접속 방식과 기존의 p-persistent 방법의 성능을 비교 분석한다.

CSMA(Carrier Sense Multiple Access) is a media access control protocol when nodes use a shared channel. To reduce the probability of collision and increase the performance, the station lust checks the state of the channel. In this paper, we study the performance improvement method based on p-persistent strategy. The p-persistent method reduces the chance of collision and improves the efficiency. However, a probability p and the number of station affect the performance. This paper proposes a dynamic CSMA multiple access based on the network status. If the possibility of collision is low, the station increases the probability p to improve the performance. In the opposite case, the station decreases the probability p. Our simulation results show that the proposed scheme outperforms any methods of CSMA multiple access according to the current persistent strategy.

Neurostenalgia is a neuropathic pain that results from continuing irritation of an anatomically intact nerve by a noxious agent. The pain resolves promptly after surgical release of the nerve. The authors report a case of neurostenalgia of the radial nerve in which the posterior interosseous branch was compressed at the arcade of Frohse, presenting with severe arm and elbow pain. The pain was immediately relieved after surgical release of the nerve.

Objective To evaluate the analgesic effect of intrathecal gabapentin therapy on secondary hyperalgesia in a rat model of persistent muscle pain.Methods Intrathecal catheters were implanted into rats. Mechanical secondary hyperalgesia was induced by repeated intramuscular injections of acidic solution into the gastrocnemius muscle. Gabapentin was administrated intrathecally. Rats were allocated to control and experimental (gabapentin 30, 100, 300, and 1,000 mg) group. After gabapentin administration, mechanical withdrawal threshold was measured every 15 minutes and the motor function was measured 30 minutes later.Results Mechanical hyperalgesia was evoked after the second acidic buffer injection. There was a significant improvement on the mechanical threshold after administration of 100, 300, and 1,000 mg gabapentin compared to pre-injection and the control group. The analgesic effect continued for 105, 135, and 210 minutes, respectively. To discern side effects, motor function was measured. Motor function was preserved in both groups after gabapentin administration, except for rats who received 1,000 mg gabapentin.Conclusion Intrathecal gabapentin administration produces dose-dependent improvements in mechanical hyperalgesia in a persistent muscle pain rat model. This implicates the central nervous system as having a strong influence on the development of persistent mechanical hyperalgesia. These results are helpful in understanding the pathophysiology of secondary hyperalgesia and in the treatment of patients with chronic muscle pain.

Aim First time mothers faced with a continuously crying infant, who do not know how to stop their child from crying, are at risk of developing anxiety and other types of Emotional Unrest. Because continuous Emotional Unrest may lead to an emotional crisis, it is important for healthcare providers to understand causal factors associated with Emotional Unrest among first time mothers faced with a persistently crying infant 6?7 weeks postpartum. Methods A cross-sectional survey was carried out on a study population of 217 first time mothers with infants aged 6?7 weeks. A self-administered questionnaire was used to measure Emotional Unrest, Neighborhood Social Organization, Effective Parenting Support, Understanding of Crying and the Effect of Information Available on Crying, Current Parenting Environment and Characteristics of the Mother and Child. Potential causal factors for Emotional Unrest were explored using structural equation modeling. Results One hundred and thirty two (60.8%) of the mothers experienced persistent crying in the period 6?7 weeks after the birth of their child and 108 (49.7%) mothers experienced Emotional Unrest. Factor analysis revealed five important constructs to be causal factors of Emotional Unrest: Effective Parenting Support, Effective Assistance with Regard to Crying, Confused by Information, Neighborhood Social Organization and Feelings of Fatigue and Anxiety. Structural equation modeling indicated that Effective Parenting Support, Effective Assistance with Regard to Crying, Confused by Information and Neighborhood Social Organization affect Feelings of Fatigue and Anxiety, which then leads to Emotional Unrest. Conclusion This study demonstrated that it will be necessary in future for health-care workers to provide early intervention, such as accurate information about crying as well as concrete and appropriate response measures for dealing with crying. Furthermore, in motherhood/parenting classes and the discharge guidance conducted at birthing centers, it will be necessary to provide guidance on what kind of effective support and local area resources are available to parents following the birth of their child.

Background Persistent spinal pain syndrome (PSPS) can be caused by a variety of causes, making it difficult to provide effective treatment. In this regard, various interventions such as neuro-mobilization and myofascial release therapy have been proposed recently, but further research is required due to the diverse patient characteristics. Therefore, the purpose of this study is to apply diagnosis and intervention based on the Movement system impairment (MSI) approach to PSPS patients and to propose the MSI approach as a method for treating PSPS patients. Study design Case report Observations The patient is a 17-year-old male PSPS patient with ongoing symptoms of pain, numbness, and weakness following a laminotomy. The patient had been experiencing symptoms for 6 months, which were aggravated by sitting or standing for more than 10 minutes. Based on the MSI approach, the patient was diagnosed with radiculopathy. The patient performed an exercise program consisting of MSI-based exercises to relieve his symptoms. After treatment, the patient's pain at rest and with activity improved to 0 on a visual analog scale, and his overall muscle weakness improved to mostly normal. Functional movement assessments showed recovery of functional movement of the lumbar-pelvic-hip complex between trunk flexion and extension. Conclusions This study shows that diagnosis and treatment based on the MSI approach is effective for patients with PSPS.

This video study examines teachers’ questioning practices in English language classrooms in Malaysia, and how different types of questions, wait time, and reaction moves influence classroom interaction. The study found that although there was an overarching monologicality across all classrooms, teachers’ questioning practices were not limited to the typical, monologic mixture of display questions, non-existent or short wait time, and/or reaction moves which could obstruct student talk. There were also opportunities for dialogicality initiated through teachers’ employment of referential questions, longer wait time, and/or reaction moves which could facilitate advanced student talk, but monologicality in classroom interaction persisted. Such observation directs our attention to the understanding and further contemplation that nurturing dialogicality is not a mere issue of strategy use.

This paper provides a comprehensive overview of the present status of several environmental problems caused by emerging toxic substances such as persistent organic pollutants (POPs), endocrine disrupting chemicals (EDCs), and arsenic in various environmental media in Vietnam. Monitoring data reported during the 1990s demonstrated elevated contamination of DDTs in most of these compartments in Vietnam. Studies in frame of the Asia-Pacific Mussel Watch Program revealed that fish, mussels and resident birds from Vietnam contained higher concentrations of DDTs as compared to other countries in region, suggesting the role of Vietnamese environment as a significant emission source of DDT in the Southeast Asian region. The estimated dietary intakes of PCBs and DDTs for Vietnamese were relatively high among Asian developing countries, suggesting potential risk for humans posed by thesechemicals. Widespread contamination of some endocrine active compounds such as alkylphenols and phthalates was observed at various sites along the coasts of northern and middle Vietnam. The presence of significant source of bisphenol-A along Red River estuary was revealed with the concentrations comparable to those reported for developed nations. A case study on seasonal variation of alkylphenols and phthalates in surface water of river delta and estuary of north and middle Vietnam indicated the differences in distribution of these compounds between dry and rainy seasons. Higher concentrations of alkylphenols and phthalates were found in dry season in estuary; while the contrasting pattern was observed in the river delta, showing elevated residues in rainy season. This result suggests the different behavior of alkylphenols and phthalates in river delta and coastal environment. From ecotoxicological perspectives, concentrations of bis-phenol A and di(2-ethylhexyl)phthalates [DEHP] in surface water from some locations in Vietnam exceeded the guideline values for Ecotoxicological Effects and the Environmental Risk Limit, respectively, suggesting potential for toxic implications on aquatic wildlife. Widespread and elevated arsenic contamination was discovered inour recent surveys in groundwater in a large area of suburban areas of Hanoi city, the capital of Vietnam. The most recent investigation in 4 villages showed about more than 50 % of groundwater samples contained As concentrations exceeding 50 g/L (the WHO and Vietnamese standard). In particular, in Son Dong villages, 58 % of samples analyzed contained As concentrations higher than 200 g/L. Good correlations were found in As concentrations in water and hair and urine of peoples in corresponding families, suggesting the chronic exposure to As by people living in As-contaminated ground water areas. In Son Dong village, As levels in hair (mean: 1.7 mg/kg dry wt) and urine (g/g creatinine) exceeding the reference values recommended by WHO, suggesting potential for human risk posed by long term accumulation of As in human body. Future studies should be focused on the time trends of POPs and EDCs in biota in Vietnam in order to predict future trend of contamination and to reveal new clues for understanding possible toxic impacts on aquatic organisms. The issues of arsenic contamination in groundwater and their chronic toxic implications on human health should be systematically investigated in the future.

경피적 경막외신경성형술(percutaneous epidural neuroplasty, PEN)은 요추 추간판 탈출증이나 척추관 협착 증과 같은 병변에 의해 발생하는 하지 방사통(radiculopathy)에 대해 효과적인 중재적 치료법으로 널리 사용되 고 있다. 그러나 일부 환자에서는 시술 직후 일시적인 통증 완화에도 불구하고 기능적으로 의미 있는 통증이 잔 존하며, 이는 PEN 단독으로는 해결되지 않는 병태생리적 원인이 존재함을 시사한다. 본 증례보고에서는 PEN 이후에도 하지 통증이 지속되는 두 명의 환자에 대해 초음파 유도하 근막 수압박리술(fascial hydrodissection, FHD)을 적용하여 임상적으로 유의한 통증 경감 및 기능 회복을 이끌어낸 사례를 기술한다. 특히 본 증례는 Luigi Stecco의 근막 해부학(fascial anatomy) 및 근막 도수치료(fascial manipulation, FM) 이론에 근거하여, 근막의 병리적 긴장 및 활주 장애(glide dysfunction)가 PEN 이후에도 지속되는 통증의 기전 중 하나일 수 있음을 전제로 하였다. 이에 따라 CC(Center of coordination) 및 CF(Center of fusion) 포인트를 치료 대상으로 설정 하고, 초음파를 이용하여 정확히 타겟팅된 부위에 FHD를 시행하였다. 시술 후 두 증례 모두에서 통증의 현저한 감소뿐 아니라 일상생활 기능의 개선이 관찰되었으며, 이는 하지 통증에 있어 근막 병변이 신경병증성 통증의 잔 존 원인으로 작용할 수 있음을 시사한다. 본 증례는 PEN 이후에도 완전히 소실되지 않는 하지 통증에 대해 근막 을 치료 타깃으로 설정한 FHD의 적용이 효과적인 치료 전략이 될 수 있음을 보여주는 임상적 근거로서 의의가 있다.

목적: 본 연구는 인플루언서 속성이 고객과의 관계 유지, 구매 의도 및 브랜드 참여에 미치는 영향을 분석하고자 한다. 동시에 관계 유지와 구매 의도가 브랜드 참여에 미치는 조절 효과를 이해하고자 한다. 추가적으로, 이 과정에서 성별과 제품 사용량에 따른 차별 적인 직접 및 간접 관계를 검증하고자 한다. 방법: 본 연구의 표본은 전체 인구를 대표하는 320명의 응답자로 구성되었으며, 설문지 의 측정 항목들은 기존 문헌을 바탕으로 일부 수정하여 사용되었다. 통계 분석을 위해서는 SPSS 소프트웨어가 사용되었다. 우선적 으로 연구에서 사용된 구성 개념들의 신뢰성을 검증하고, 연구 질문을 검증하기 위해 다중 회귀 및 매개 모델을 사용하였다. 결과: 연구 질문 1에 대한 분석 결과는 인플루언서의 모든 속성들이 관계 유지와 구매 의도에 유의미한 영향을 미친다는 것을 보여주었 다. 하지만 인플루언서의 세부 속성들 중에서 친숙함만이 지속적인 브랜드 참여에 중요한 영향을 미친다는 것을 확인하였다. 이러 한 결과는 기업이 목표 고객과 유사한 인플루언서를 신중하게 선택해야 함을 시사한다. 또한 간접 효과를 검증하는 연구 질문 2에 대한 분석 결과는 인플루언서 속성들이 브랜드 참여에 미치는 영향을 관계 유지와 구매 의도가 통계적으로 유의하게 매개한다는 것 을 시사한다. 결론: 따라서 긍정적인 장기적 브랜드 참여를 달성하고 유지하기 위해서는 인플루언서 마케팅에 참여하는 인플루언서 와의 긍정적인 관계를 유지하고, 소비자의 경험과 제품에 대한 피드백을 강조하는 것이 매우 중요하다

Purpose: This study analyzes the effects of influencer attributes on relationship maintenance, purchase intention, and brand engagement. In doing so, we also attempt to understand the moderating effects of relationship maintenance and purchase intention on brand engagement. In addition, we also verified the differential direct and indirect relationship between gender and product usage. Methods: The study sample comprises 320 respondents representing the overall population. The measurement items in the questionnaire were based on previous literature with some modifications. The SPSS software was utilized for statistical analyses. We first verified the reliability and validity of the research constructs and used multiple regression and mediation models to confirm the research questions. Results: Research question 1’s results showed that influencers’ attributes significantly affect relationship maintenance and intention of purchase. However, just the familiarity of an influencer significantly affects persistent brand engagement. These findings imply that firms need to carefully choose influencers, who closely resemble their target customers for close representation. The indirect effects in research question 2’s results show that relationship maintenance and purchase intention significantly mediate the effects of influencer attributes on brand engagement. Conclusion: Thus, to achieve positive long-term brand engagement, it is crucial to maintain a positive relationship with participating influencers and emphasize consumers’ experience and feedback with the focal products.

본 연구는 온라인 공동체에서 구성원들 간에 신뢰가 어떻게 형성 발전되는지를 살펴보기 위한 연구이다. 신뢰형성에 주요한 요인에 대한 이론적 고찰을 통해 본 연구는 사회적정체성과 지속적인 커뮤니케이션 활동을 주요한 요인으로 설정하고 이들과 신뢰(Trust)에 이르기 위한 매개변인들인 신뢰성 (Trustworthiness) 요소-Integrity (규범공유성), 선의(Benevolence), 개방성(Openness)-와의 관계를 살펴보았다. 이들 관계를 실증적으로 밝히기 위해서 본 연구는 국내 주요 온라인 사이트의 커뮤니티 구성원을 대상으로 설문을 실시하였다. 그 결과, 사회적정체성과 지속적인 커뮤니케이션이 신뢰성(Trustworthiness)에 유의미한 영향을 주고 있었으며 신뢰성의 세 가지 변인(Integrity, Benevolence, Openness) 등은 기존의 연구와 유사하게 신뢰에 주요한 요소들임이 밝혀졌다.

The current study investigated how interpersonal trust is developed in online communities, where most of individual identities are unknown or doubtful. To better understand and theorize the underlying mechanism, a survey was conducted integrating the literature on computer-mediated communication (CMC) and extending previous research on social identify model. The findings confirmed that integrity, benevolence, and openness are essential components in the concept of trustworthiness, which is predicted by social identification and persistency of communication activities in the virtual community.

북한 핵문제의 이슈에 대해 중국의 역할은 최근 몇 년간 중요한 변화를 겪어왔다. 6자 회담의 첫해엔 중국의 역할을 외교과정에서 촉진제, 중개인 및 주인이었다. 그러나 2007년 이후 북미 양자 관계는 한국 핵 외교에 지배적인 요인으로 부각되었으며, 크게 소외된 중국 그리고 이러한 노력 속에 포함된 3강은 소외되었다. 그 결과로, 중국은 대체로 그 대화들과 워싱턴과 평양 사이에서 이미 성취된 rubber-stamping협정에서 손님의 역할로 한정되어져 왔다. 중국은 3가지 주요 관심사 사이에서 쉽지 않은 균형을 찾기 위해 노력하고 있다. (1)한반도의 평화를 보증하는 것; (2)북한의 비핵화를 조장하는 것; (3)북한과의 지속되어 왔던 관계를 보전시키는 방법을 찾는 것이다.

China’s role in the North Korean nuclear issue has undergone major change in recent years. In the initial years of the Six-Party Talks, China’s role was central as facilitator, arbiter, and host of the diplomatic process. However, since 2007 the U.S.-North Korea bilateral relationship has been the dominant factor in Korean nuclear diplomacy, largely marginalizing China and the other three powers involved in these efforts. As a result, China has been confined principally to hosting the talks and to rubber-stamping agreements already achieved between Washington and Pyongyang. China continues to seek an uneasy balance among three vital interests: (1) ensuring peace on the peninsula; (2) fostering North Korea’s denuclearization; and (3) seeking to preserve a continued relationship with North Korea. But it has yet to develop a full strategy for reconciling these interests and managing its policy priorities. However, China has accelerated its economic and political ties with both the Republic of Korea (ROK) and the Democratic People’s Republic of Korea (DPRK). Beijing therefore seems well positioned for the peninsula’s longer-term evolution, including its hopes that North Korea will ultimately move toward a more ‘‘reformist’’ orientation and a much-diminished emphasis on military power in its national strategy. China’s policy efforts on the “parallel friendships” with both DPRK and ROK suggest one major point: Beijing has been pursuing “gently” her long-term interests and influence in the Peninsular while maintaining and expanding the room of future policy options, all with a kind of almost unique patience and stamina. To these, China’s deep involvement in the international efforts to solve the North Korea nuclear problem (including her initiating and sponsoring Six-Party Talks) is also quite advantageous, because it has greatly increased the frequency and intensity of her political intercourses with both Koreas. However, dilemmas in Chinese policymaking persist, with Beijing able to influence but not control the major uncertainties, especially at least those related to North Korea’s short term political future.

Chronic postsurgical pain (CPSP) is a significant complication that can severely affect quality of life, particularly in cases involving facial fractures due to the complex neural anatomy. This case involves a 70-year-old female with persistent facial pain, dysesthesia, and nasal discomfort for 2.5 years after orbital and zygomatic complex fracture repair. Despite more than six months of pharmacological treatment, symptoms persisted; therefore, we performed an ultrasound-guided infraorbital nerve block (IONB). After six sessions, the patient experienced a 70% reduction in pain and sustained improvement in symptoms, including decreased nasal sensation as if having a runny nose. This case demonstrates the efficacy of IONB as a safe and effective treatment for managing CPSP and neuropathic symptoms associated with infraorbital nerve injury, even in cases with prolonged symptom duration.

목적: 본 연구는 미용전공 대학생의 자원봉사활동 참여동기가 자아성취감 및 활동지속에 미치는 영향을 확인하여 미용전공 봉사활 동 활성화하기 위한 기초자료를 제공하는 것에 연구의 목적이 있다. 방법: 조사기간은 2023년 6월 1일부터 6월 10일까지 대구 경북 소재 4년제 미용전공 대학생을 대상으로 총 280부를 배포하여 8부를 제외한 272부를 최종 분석 자료로 활용하였다. 결과: 자원봉 사활동 참여동기가 자아성취감에 미치는 영향은 참여동기 중 자기개발동기, 대의적 동기, 여가적 동기가 높아지면 능력발휘, 목적 이상실현에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 활동지속에 미치는 영향은 자기개발 동기, 대의적동기가 지속의지에 유의미한 정(+)의 영향, 대의적 동기, 여가적 동기가 참여강도에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 자아성취감이 활동지속에 미치는 영향은 목적이상실현, 능력발휘가 자아성취감, 참여강도에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 결론: 미용전공 대학생의 자원봉사활동 참여동기가 높아지면 자아성취감, 활동지속도 높아지면, 자아성취감중 목적이상실현, 능력 발휘가 높아지면 활동지속도 높아지는 것으로 확인 되었다

Purpose: The purpose of this study was to identify the effects of motivation to participate in volunteer activities on self-fulfillment and persistent participation among cosmetology students and to provide basic data to encourage volunteering in the field of cosmetology. Methods: The survey extended from June 1 to June 10, 2023, and a total of 280 copies were distributed to university students majoring in cosmetology during their 4-year course at a university located in Daegu, Gyeongbuk. After excluding 8 copies, 272 copies were used for final analysis. Results: Among several participation motivations, this study revealed that increasing selfdevelopment motivation, purposive motivation, and leisure motivation had a significant positive effect on ability exhibition and purposeful ideal realization. Selfdevelopment motivation and purposive motivation had a significant positive effect on persistent participation in volunteer activities, whereas purposive motivation and leisure motivation had a significant positive effect on participation intensity. Further, the results showed that purposeful ideal realization and ability exhibition had a significant positive effect on self-fulfillment and participation intensity. Conclusion: It was confirmed that higher motivation to participate in volunteer activities among students majoring in cosmetology increased their self-fulfillment. Further, a higher rate of persistent participation in activities enhanced purposeful ideal realization in self-fulfillment, and a higher level of ability exhibition increased persistent participation in volunteer activities.

目的: 探讨美容专业学生参与志愿者活动的动机对自我实现和持续参与的影响，为鼓励美容领域的志愿服务提供 基础数据。方法: 调查时间为2023年6月1日至6月10日，向庆尚北道大邱市一所大学四年制美容专业的大学生发 放了总共280份调查问卷。除去8份后，共272份用于最终分析。结果: 在多种参与动机中，本研究发现增加自我 发展动机、目的性动机和休闲动机对能力展示和有目的性理想实现具有显着的正向作用。自我发展动机和目的 性动机对志愿者活动的持续参与有显着的正向影响，而目的性动机和休闲动机对参与强度有显着的正向影响。 进一步，结果表明，有目的的理想实现和能力展示对自我实现和参与强度有显着的正向影响。结论: 证实美容专 业学生参与志愿者活动的动机较高，可以增加他们的自我实现感。此外，较高的持续参与活动率增强了自我实 现中有目的的理想的实现，较高水平的能力展示增加了对志愿者活动的持续参与。

Conversion disorder is often characterized by various neurological symptoms affecting motor and sensory functions, with unknown mechanism. Although the disease can be presented with various symptoms, persistent dysphagia due to conversion disorder is quite rare. A 42-year-old male, diagnosed with conversion disorder, suddenly developed swallowing difficulty without preceding event. Full neurologic examination and brain MRI findings were found to be normal but the symptom persisted for 10 years despite medical treatments. The patient visited our clinic for dysphagia rehabilitation program. Videofluoroscopic swallowing study (VFSS) findings revealed significant difficulty in initiation of swallowing and bolus transfer during oral phase, but no abnormal patterns were noticed during pharyngeal and esophageal phases. Initiation difficulty of swallowing by voluntary effort raised suspicion of oromotor apraxia, and limb and oral apraxia test demonstrated positive findings of apraxia. The patient underwent conventional dysphagia rehabilitation programs and rTMS treatment over supplementary motor area to modulate motor network. On follow up VFSS, some improvements in oral transit time and bolus transfer were noted. Persistent dysphagia due to conversion disorder is very uncommon and this case showed the possibility of improvement of symptom in conversion disorder with conventional dysphagia rehabilitation programs.

Cauda equina syndrome (CES) is a rare complication of spinal and epidural anesthesia. We report a case of persistent cauda equina syndrome after epidural anesthesia with single shot 0.5% bupivacaine. There was no pain or paresthesia during needle placement or drug injection. 35-year-old woman experienced pain and weakness in the both lower extremities and alterations in bowel and urinary habits after epidural anesthesia for caesarean section. Electrodiagnostic examination revealed asymmetric bilateral lumbosacral polyradiculopathies compatible with cauda equine syndrome. The patient MRI revealed arachnoiditis, but did not show suspicious lesions such as hematoma and abscess. She was treated with medication, bladder training and physical therapy, but her symptoms remained unchanged during a 2 year follow- up. We suggest the chronic adhesive arachnoiditis resulting from bupivacaine neurotoxicity have played a role in producing this devastating chronic complication.