• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.317-328
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• 2019

It is known that top-down associative inputs terminate on distal apical dendrites in layer 1 while bottom-up sensory inputs terminate on perisomatic dendrites of layer 2/3 pyramidal neurons (L2/3 PyNs) in primary sensory cortex. Since studies on synaptic transmission in layer 1 are sparse, we investigated the basic properties and cholinergic modulation of synaptic transmission in layer 1 and compared them to those in perisomatic dendrites of L2/3 PyNs of rat primary visual cortex. Using extracellular stimulations of layer 1 and layer 4, we evoked excitatory postsynaptic current/potential in synapses in distal apical dendrites (L1-EPSC/L1-EPSP) and those in perisomatic dendrites (L4-EPSC/L4-EPSP), respectively. Kinetics of L1-EPSC was slower than that of L4-EPSC. L1-EPSC showed presynaptic depression while L4-EPSC was facilitating. In contrast, inhibitory postsynaptic currents showed similar paired-pulse ratio between layer 1 and layer 4 stimulations with depression only at 100 Hz. Cholinergic stimulation induced presynaptic depression by activating muscarinic receptors in excitatory and inhibitory synapses to similar extents in both inputs. However, nicotinic stimulation enhanced excitatory synaptic transmission by ~20% in L4-EPSC. Rectification index of AMPA receptors and AMPA/NMDA ratio were similar between synapses in distal apical and perisomatic dendrites. These results provide basic properties and cholinergic modulation of synaptic transmission between distal apical and perisomatic dendrites in L2/3 PyNs of the visual cortex, which might be important for controlling information processing balance depending on attentional state.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.270-276
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• 2023

Objective: This study investigated the clinical and laboratory factors associated with the presence of dysmorphic oocytes in intracytoplasmic sperm injection (ICSI) cycles. Methods: The study involved 200 ICSI cycles, performed from 2020 to 2021, that yielded at least one mature oocyte. Clinical characteristics and ovarian stimulation methods were compared between 68 cycles with at least one dysmorphic oocyte (the dysmorphic group) and 132 cycles with normal-form oocytes only (the non-dysmorphic group). Dysmorphic oocytes were characterized by dark cytoplasm, cytoplasmic granularity, cytoplasmic vacuoles, refractile bodies in the cytoplasm, smooth endoplasmic reticulum in the cytoplasm, an oval shape, an abnormal zona pellucida, a large perivitelline space, debris in the perivitelline space, or an abnormal polar body. Results: The ages of the women, indications for in vitro fertilization, serum anti-Müllerian hormone levels, and rates of current ovarian endometrioma were similar between the dysmorphic and non-dysmorphic groups. In both groups, the three ovarian stimulation regimens, two types of pituitary suppression, and total gonadotropin dose were employed similarly. However, the dual-trigger method was used more frequently in the dysmorphic group (67.6% vs. 50%, p=0.024). The dysmorphic group contained significantly more immature oocytes and exhibited significantly lower oocyte maturity (50% vs. 66.7%, p=0.001) than the non-dysmorphic cycles. Within the dysmorphic group, significantly lower oocyte maturity was found in the cycles using a dual-trigger, but not in those with a human chorionic gonadotropin trigger. Conclusion: ICSI cycles with dysmorphic oocytes are closely associated with reduced oocyte maturity. This association was observed exclusively in dual-trigger cycles.

• Journal of Biomedical Engineering Research
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• v.45 no.2
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• pp.101-107
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• 2024

Steady-state visual evoked potential-based brain-computer interface (SSVEP-BCI) is one of the promising systems that can serve as an alternative input device due to its stable and fast performance. However, one of the major bottlenecks is that some individuals exhibit no or very low SSVEP responses to flickering stimulation, known as SSVEP illiteracy, resulting in low performance on SSVEP-BCIs. However, a lengthy duration is required to enhance multiple SSVEP responses using traditional single-frequency transcranial alternating current stimulation (tACS). This research proposes a novel approach using dual-frequency tACS (df-tACS) to potentially enhance SSVEP by targeting the two frequencies with the lowest signal-to-noise ratio (SNR) for each participant. Seven participants (five males, average age: 24.42) were exposed to flickering checkerboard stimuli at six frequencies to determine the weakest SNR frequencies. These frequencies were then simultaneously stimulated using df-tACS for 20 minutes, and the experiment was repeated to evaluate changes in SSVEP responses. The results showed that df-tACS effectively enhances the SNR at each targeted frequency, suggesting it can selectively improve target frequency responses. The study supports df-tACS as a more efficient solution for SSVEP illiteracy, proposing further exploration into multi-frequency tACS that could stimulate more than two frequencies, thereby expanding the potential of SSVEP-BCIs.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.376-380
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• 2006

Temperature distribution measured to estimate the condition of an electrical apparatus is an absolute reference for the apparatus conditions and the difference between the reference temperature and the current temperature. Because of passive thermography, without the external thermal stimulation, the difference in surface temperature between the region of interest and back ground shows that the results can apply only to the estimation or the monitoring for the condition of loose terminal and the overload pertaining to the rise in temperature. However, a thermal diffusion in the active thermography is differently generated by the structure and condition of the surface and subsurface. This paper presents a nondestructive test using this behavior and deals with the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

• Journal of Oral Medicine and Pain
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• v.42 no.3
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• pp.53-61
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• 2017

Myogenous temporomandibular disorder is a collective term for pathologic conditions of the masticatory muscles, mainly characterized by pain and dysfunction associated with various pathophysiological processes. Among the subtypes of myogenous temporomandibular disorder, myofascial pain is one of the most common muscle disorders, characterized by the presence of trigger points (TrPs). Various modalities, such as ultrasound, manipulative therapy, spray-and-stretch technique, transcutaneous electrical nerve stimulation, injection/dry needling, and low-level laser therapy are used to inactivate TrPs. Needling/injection on the TrPs is one of the most common treatments for myofascial pain. Despite the evidence, there is continued controversy over defining the biological and clinical characteristics of TrPs and the efficacy of injection/dry needling. This review discusses the current concept of injection/needling to relieve TrPs.

• Korean Institute of Interior Design Journal
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• v.14 no.2 s.49
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• pp.161-168
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• 2005

Kindergarten is the first educational experience of toddlers, where they experience living in a group environment. Carefully designed, it is intended to provide an environment for nurturing the systematic growth and development of youngsters. Through effective stimulation, young children display their abilities as they independently learn in the controlled setting of Kindergarten. This study advocates the support of educational activities through the use of systematic and scientific architectural design in order to achieve the challenging goals and results desired of Kindergarten education. Upon determining the current state of Kindergarten architectural design, I have sought to apply innovative architectural concepts which can be used to design desirable learning environment for Kindergarten aged children. In calculation of area, the average gross building area is minimum $2.3m^{2}/p$ and optimum $2.5m^{2}/p$. The area of classroom is optimum $6.8m^{2}/p$.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.808-811
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• 2012

매년 높은 비율의 전기안전사고가 발생하지만 예방교육은 단순한 영상홍보나 단순 텍스트를 이용한 교육 수준에서 주입식으로 이루어지고 있다. 항공, 군사, 전력산업 등 다양한 분야에서는 가상현실을 이용한 체험형 교육 시스템이 개발되어 운영되지만 전기안전 예방교육은 감전사고와 같은 특수한 상황의 체험과 사고를 유발시킬 수 있다는 측면에서 체험형 교육시스템이 개발 및 적용이 어렵다. 따라서 본 연구에서는 전기감전 체험교육 시스템에 저주파 자극 장치를 사용할 수 있도록 저주파 간섭형 자극기를 이용한 인체 자극의 임계값 산출시험을 실시하고 대표적으로 성별, 연령별(아동 및 성인 구분)로 구분하여 적절한 자극값을 산출하였다. 본 연구의 결과는 향후 전기안전사고 예방을 위한 체험형 예방 교육 시스템에 활용이 가능할 것이다.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.97-99
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• 2012

본 연구는 본 연구는 경두개직류자극(transcranial direct current stimulation)을 편마비 환자의 대뇌피질 운동영역에 적용하여 상지기능에 미치는 효과를 알아보고자 실시하였다. 뇌졸중으로 인해 편마비된 환자를 대상으로 두 군으로 구분하여 경두개직류자극과 일반적인 물리치료를 함께 시행하였고, 실험 전후의 두 군의 기능적 평가항목과 전기생리학적 평가를 함께 실시하였다. 통계처리 방법으로 실험 전 후 차이를 검증하였고, 모든 통계적 유의수준은 0.05로 하였다. 본 연구의 결과 실험군과 대조군에서 주관절 기능평가의 값과 손 기능 평가에서 치료 전, 후 값이 증가하였고 통계적으로 유의한 차이를 보였다(p<0.05). 결론적으로, 경두개직류자극이 뇌졸중 환자의 상지기능에 변화에 효과적인 것으로 나타났다. 따라서, 임상에서 뇌졸중 환자를 대상으로 한 경두개직류자극의 활용 가능성에 대해 재활 관점에서의 추가적인 연구가 더욱 필요할 것으로 생각된다.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.209-212
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• 1992

A major technical problem in encountered in nerve stimulation technique is the control of stimulus artifact and the convenience of nerve stimulator. The artifacts remained must be removed by processing the contaminated signal. This paper discusses about the artifact cancellation algorithms in constant voltage type nerve stimulator(CVS) and constant current type nerve stimulator(CCS).

• Korean Journal of Child Studies
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• v.29 no.3
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• pp.273-288
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• 2008

Types of motivation for self-determination studied in the current research included intrinsic motivation (IM) to know, IM to accomplish, IM to experience stimulation; external, introjected, identified regulation; and amotivation as related to children's self-regulated learning strategies (use of cognitive strategy and self-regulation). The Motivated Strategies for Learning Questionnaire (Pintrich & DeGroot, 1990) and the Academic Motivation Scale (Vallerand et al., 1992, 1993) were administered to 123 $5^{th}$ graders (63 girls, 60 boys). Data were analyzed by Pearson's correlation, multiple regression, and canonical correlation analysis. Results indicated that IM to accomplish, IM to know, and identified regulation positively and amotivation negatively affected self-regulated learning strategies. IM to accomplish and IM to know positively and amotivation negatively contributed to use of cognitive strategy and self-regulation.