Earticle

Scheduling practice sessions to create a spacing effect enhances L2 pronunciation and fluency. Such manipulation of practice sessions is also conducive to better L2 vocabulary and grammar retention. Blocking and interleaving are task manipulation methods widely discussed in recent times as effective methods of L2 teaching. The present study measured the difference in the effect of these two methods on the enhancement of English pronunciation and fluency and on the retention of English vocabulary and grammar by keeping Indian adolescent ESL learners (N=64) under blocked and interleaved conditions during a three-month-long speaking proficiency training program in English. Three tests were conducted during the program to assess the differences in speech performance. Speech samples collected from the participants at different stages of the program were evaluated in pronunciation, fluency, vocabulary, and grammar by four external assessors. The test scores collected in these tests were analyzed using repeated measures ANOVA. Although the blocked group produced oral responses in English that exhibited a bit more flexibility, appropriacy, and complexity in word choice as well as sentence construction and less phonological error and hesitation, the study recorded no statistically significant differences in the effect of these two methods on the English speaking proficiency of the participants.

এটা ব্যৱধান 􀏕ভাৱ সৃ􀎜􀑭 কিৰবৈল অনুশীলন অিধেবশনসমূহৰ সময়সূচী িনধর্াৰণ কিৰেল L2 উ􀐗াৰণ আ􁃋 সাৱলীলতা বৃ􀎝􀐴 পায়। অনুশীলন অিধেবশনৰ এেন েহতািল েখলােটাও উ􀑂ত এল ২ শ􀑏ভা􀐦াৰ আ􁃋 ব্যাকৰণ ধিৰ ৰখাৰ বােব অনুকূল। 􀑓ক আ􁃋 ই􀐻াৰিলিভং ৈহেছ কাযর্্য েহতািল েখলা প􀐴িত িযেবাৰক েশহতীয়াৈক এল ২ পাঠদানৰ ফল􀏕সূ প􀐴িত িহচােপ ব্যাপকভােৱ আেলাচনা কৰা ৈহেছ। ভাৰতীয় িকেশাৰ ই এছ এল িশ􀏠াথ􀎻সকলক (N=64) িতিন- ইংৰাজী ভাষাত মাহেজাৰা বক্তৃতা দ􀏠তা 􀏕িশ􀏠ণ কাযর্সূচী। কাযর্সূচীৰ সময়ত বাক্যৰ 􀏕দশর্নৰ পাথর্ক্য মূল্যায়নৰ বােব িতিনটা পৰী􀏠া কৰা ৈহিছল। কাযর্সূচীৰ িবিভ􀑂 পযর্ায়ত অংশ􀏂হণকাৰীসকলৰ পৰা সং􀏂হ কৰা বক্তৃতাৰ নমুনাসমূহ উ􀐗াৰণ, সাৱলীলতা, শ􀑏ভা􀐦াৰ আ􁃋 ব্যাকৰণৰ ে􀏠􀏏ত চািৰজন বািহ্যক মূল্যায়েক মূল্যায়ন কিৰিছল। এই পৰী􀏠াসমূহত সং􀏂হ কৰা পৰী􀏠াৰ ন􀑗ৰসমূহ পুনৰাবৃি􀐫মূলক পদে􀏠প ANOVA ব্যৱহাৰ কিৰ িবে􀑫ষণ কৰা ৈহিছল। যিদও 􀑓ক কৰা েগাটেটােৱ ইংৰাজী ভাষাত েমৗিখক সঁহািৰ উৎপ􀑂 কিৰিছল িযেয় শ􀑏 বাছিনৰ লগেত বাক্য িনমর্াণৰ ে􀏠􀏏ত অলপ েবিছ নমনীয়তা, উপযু􀐅তা আ􁃋 জ􀎜টলতা 􀏕দশর্ন কিৰিছল আ􁃋 কম 􀐹িনতা􀎝􀏬ক ভ􀎦ল আ􁃋 ি􀐵ধােবাধ, অধ্যয়নেটােৱ এই দুটা প􀐴িতৰ 􀏕ভাৱৰ ে􀏠􀏏ত েকােনা পিৰসংখ্যাগতভােৱ 􁃕􁃋􀐯পূণর্ পাথর্ক্য িলিপব􀐴 কৰা নািছল অংশ􀏂হণকাৰীসকলৰ ইংৰাজী েকাৱাৰ দ􀏠তা।

This current study explores effects of productivity of English suffixes, such as -al, -ance, -tion, -ment, and of blocking of the word formation rules. The results are as follows: First, the lexicon has Nominal Affixations Rules, which are specified on the lexical item according to their applicability of the rules. And eight verb types are classified with the set of the Nominal Affixation Rules according to whether or not the following rules are applied. Second, common features are as follows: (a) All the verbs to which nominal affixes are attached have prefixes in them. (b) All the verbs to which nominal affixes are attached are two-syllabled words and have the stress on the second syllable. Third, the analysis of the data made us find out the following individual features: (a) Words beginning with the prefixes re-, pro-, de-, con- can have suffixes -al, -tion but not the suffixes -ance and -ment. (b) Words with the prefixes ar- transformed from ad- can have the suffixes -ance and -ment.. (c) Words with the prefixes ac-, ap- changed from ad- cannot have the suffix -ance but can have the suffix -ment. However, words with the prefix directly followed by /q/ can have both -ance and -ment. (d) Word beginning with the prefixes de-, con-, per-, o(b)-, ac- as well as with the word stucture /ad- + Vowel/ cannot have the suffix -al. However, words with the prefix directly followed by /q/ can have the nominal suffix -al. The results can only have the descriptive adequacy but not the explanatory adequacy; therefore, this kind of study on the blocking can be opened to a further research.

Activation of the NLRP3 inflammasome is a necessary process to induce fibrosis in nonalcoholic fatty liver disease (NAFLD). Nonalcoholic steatohepatitis (NASH) is a kind of NAFLD that encompasses the spectrum of liver disease. It is characterized by inflammation and ballooning of hepatocytes during steatosis. We tested whether inhibiting the NLRP3 inflammasome could prevent the development and pathology of NASH. We identified loganin as an inhibitor of the NLRP3 inflammasome and investigated whether in vivo administration of loganin prevented NASH symptoms using a methionine-choline deficient (MCD) diet model in mice. We found that loganin inhibited the NLRP3 inflammasome activation triggered by ATP or nigericin, as shown by suppression of the production of interleukin (IL)-1β and caspase-1 (p10) in mouse primary macrophages. The speck formation of apoptosisassociated speck-like protein containing a caspase recruitment domain (ASC) was blocked by loganin, showing that the assembly of the NLRP3 inflammasome complex was impaired by loganin. Administration of loganin reduced the clinical signs of NASH in mice fed the MCD diet, including hepatic inflammation, fat accumulation, and fibrosis. In addition, loganin reduced the expression of NLRP3 inflammasome components in the liver. Our findings indicate that loganin alleviates the inflammatory symptoms associated with NASH, presumably by inhibiting NLRP3 inflammasome activation. In summary, these findings imply that loganin may be a novel nutritional and therapeutic treatment for NASH-related inflammation.

Previous studies have shown disrupted synaptic plasticity and neural activity in depression. Such alteration is strongly associated with disrupted synaptic structures. Chronic stress has been known to induce changes in dendritic structure in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC), but antidepressant effect on structure of these brain areas has been unclear. Here, the effects of imipramine on dendritic spine density and morphology in BLA and mPFC subregions of stressed mice were examined. Chronic restraint stress caused depressive-like behaviors such as enhanced social avoidance and despair level coincident with differential changes in dendritic spine structure. Chronic stress enhanced dendritic spine density in the lateral nucleus of BLA with no significant change in the basal nucleus of BLA, and altered the proportion of stubby or mushroom spines in both subregions. Conversely, in the apical and basal mPFC, chronic stress caused a significant reduction in spine density. The proportion of stubby or mushroom spines in these subregions overall reduced while the proportion of thin spines increased after repeated stress. Interestingly, most of these structural alterations by chronic stress were reversed by imipramine. In addition, structural changes caused by stress and blocking the changes by imipramine were corelated well with altered activation and expression of synaptic plasticity-promoting molecules such as phospho-CREB, phospho-CAMKII, and PSD-95. Collectively, our data suggest that imipramine modulates stress-induced changes in synaptic structure and synaptic plasticity-promoting molecules in a coordinated manner although structural and molecular alterations induced by stress are distinct in the BLA and mPFC.

Hesperidin has been shown to possess a potential inhibitory effect on vascular formation in endothelial cells. However, the fundamental mechanism for the anti-angiogenic activity of hesperidin is not fully understood. In the present study, we evaluated whether hesperidin has anti-angiogenic effects in mouse embryonic stem cell (mES)-derived endothelial-like cells, and human umbilical vascular endothelial cells (HUVECs), and evaluated their mechanism via the AKT/mammalian target of rapamycin (mTOR) signaling pathway. The endothelial cells were treated with several doses of hesperidin (12.5, 25, 50, and $100{\mu}M$) for 24 h. Cell viability and vascular formation were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and tube formation assay, respectively. Alteration of the AKT/mTOR signaling in vascular formation was analyzed by western blot. In addition, a mouse aortic ring assay was used to determine the effect of hesperidin on vascular formation. There were no differences between the viability of mES-derived endothelial-like cells and HUVECs after hesperidin treatment. However, hesperidin significantly inhibited cell migration and tube formation of HUVECs (P<0.05) and suppressed sprouting of microvessels in the mouse aortic ring assay. Moreover, hesperidin suppressed the expression of AKT and mTOR in HUVECs. Taken together, these findings suggest that hesperidin inhibits vascular formation by blocking the AKT/mTOR signaling pathways.

We investigated the inhibitory effects of hesperidin on melanogenesis. To find melanosome transport inhibitor from natural products, we collected the structural information of natural products from Korea Food and Drug Administration (KFDA) and performed pharmacophore-based in silico screening for Rab27A and melanophilin (MLPH). Hesperidin did not inhibit melanin production in B16F10 murine melanoma cells stimulated with ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH), and also did not affect the catalytic activity of tyrosinase. But, hesperidin inhibited melanosome transport in melanocyte and showed skin lightening effect in pigmented reconstructed epidermis model. Therefore, we suggest that hesperidin is a useful inhibitor of melanosome transport and it might be applied to whitening agent.

We demonstrate herein that silibinin, a polyphenolic flavonoid compound isolated from milk thistle (Silybum marianum), inhibits LPS-induced activation of macrophages and production of nitric oxide (NO) in RAW 264.7 cells. Western blot analysis showed silibinin inhibits iNOS gene expression. RT-PCR showed that silibinin inhibits iNOS, TNF-${\alpha}$, and $IL1{\beta}$. We also showed that silibinin strongly inhibits p38 MAPK phosphorylation, whereas the ERK1/2 and JNK pathways are not inhibited. The p38 MAPK inhibitor abrogated the LPS-induced nitrite production, whereas the MEK-1 inhibitor did not affect the nitrite production. A molecular modeling study proposed a binding pose for silibinin targeting the ATP binding site of p38 MAPK (1OUK). Collectively, this series of experiments indicates that silibinin inhibits macrophage activation by blocking p38 MAPK signaling.

A primary latest video coding standard H.265/SHVC (Scalable High Efficiency Video Coding), an extension of High Efficiency Video Coding (HEVC) is dealt in this paper. To transfer high quality video over any network that usually occupies large bandwidth, suffers bandwidth limitation. It can be controlled by trading-off between the quality and the coding efficiency. The trade-off between these two parameters is considered in this paper to keep the difference at the minimum level. A novel Neural Network based Adaptive De-blocking Filter (NNADF) technique is proposed to maintain good PSNR with minimum bit rate in SHVC encoder. The adaptive de-blocking filter (ADF) performs block matching for nonlinear predictions to all frames in the video. Moreover, the ADF performs frame de-noising hence good quality of the video is achieved and trains a neural network (NN) model. The NN model restrains their outputs to achieve bit rate reduction, thereby coding efficiency is achieved. The simulation results show that the proposed NNADF technique delivers an average increment of 0.62 dB in BD-PSNR and an average decrement of 24 % in BD-BR for combined quality and spatial ratios respectively compared with the previously proposed algorithm.

Telmisartan is an angiotensin-II receptor blocker and acts as a selective modulator of peroxisome proliferator-activated receptor gamma (PPARγ). Several studies have demonstrated that telmisartan ameliorates depression and memory dysfunction and reduces brain inflammation. We hypothesized that the beneficial effects of telmisartan on brain could be due to modulation of the blood-brain barrier (BBB) function. Here, we examined the effect of telmisartan on tumor necrosis factor alpha (TNF-α)-induced expression of intercellular adhesion molecule 1 (ICAM-1) which plays an important role in leukocyte transcytosis through the BBB. Telmisartan blocked TNF-α-induced ICAM-1 expression and leukocyte adhesion in U87MG human glioma cells but showed no effect on human brain microvascular endothelial cells. In U87MG cells, a PPAR antagonist, GW9662 did not block the effect of telmisartan on ICAM1 expression but rather potentiated. Moreover, GW9662 caused no change in TNF-α-induced ICAM-1 expression, suggesting no implication of PPARγ in the telmisartan effect. Further studies showed that telmisartan blocked TNF-α-induced activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factorkappa B (NF-κB). In contrast, inhibitors of JNK, ERK1/2 and NF-κB but not p38, blocked ICAM-1 expression induced by TNF-α. Thus, our findings suggest that the beneficial effect of telmisartan is likely due to the reduction of astrocytic ICAM1 expression and leukocytes adhesion to astrocytes, and that this response was mediated by the inhibition of JNK/ERK1/2/NF-κB activation and in the PPAR-independent manner. In conclusion, this study enhances our understanding of the mechanism by which telmisartan exerts the beneficial brain function.

We show that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibits cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$)-induced production of nitric oxide (NO) in the pancreatic beta cell line MIN6N8a. Immunostaining and Western blot analysis showed that silymarin inhibits iNOS gene expression. RT-PCR showed that silymarin inhibits iNOS gene expression in a dose-dependent manner. We also showed that silymarin inhibits extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) phosphorylation. A MEK1 inhibitor abrogated CM-induced nitrite production, similar to silymarin. Treatment of MIN6N8a cells with silymarin also inhibited CM-stimulated activation of NF-${\kappa}B$, which is important for iNOS transcription. Collectively, we demonstrate that silymarin inhibits NO production in pancreatic beta cells, and silymarin may represent a useful anti-diabetic agent.

Objective: The purpose of this study was to changes in respiratory function due to differences in mask blocking grade, and effects on cardiovascular function during aerobic exercise. Design: Comparative study using paired t-test and analysis of variance measures. Methods: Male and female subjects were randomly divided into 4 groups according to mask blocking grade and measured respiratory functions before and after wearing the mask using spirometers, and their cardiovascular capabilities were measured using pulse oxygen meters and blood pressure meters before and after running for 10 minutes wearing mask. Used paired t-test, one-way ANOVA and Bonferroni post-test to compare the differences according to the mask blocking grade. Results: The experimental results verified that three groups except for the Non-mask group had a significant reduction in all values of FVC, FEV1, MVV, and PEF after wearing a mask compared to those before wearing a mask(p<0.05). Also a significant difference in cardiovascular functions was also observed after aerobic exercises wearing mask in all groups and there was a significant difference between all four groups(p<0.05). Conclusions: Lung patients with poor breathing, elderly and children with poor lung function, and professional groups who need to wear masks and take high-intensity work or aerobic movements are encouraged to take frequent breaks in advance, wear masks and social distancing at moderate and low levels.

Fucoxanthin is an important carotenoid derived from edible brown seaweeds and is used in indigenous herbal medicines. The aim of the present study was to examine the cytoprotective effects of fucoxanthin against hydrogen peroxide-induced cell damage. Fucoxanthin decreased the level of intracellular reactive oxygen species, as assessed by fluorescence spectrometry performed after staining cultured human HaCaT keratinocytes with 2',7'-dichlorodihydrofluorescein diacetate. In addition, electron spin resonance spectrometry showed that fucoxanthin scavenged hydroxyl radical generated by the Fenton reaction in a cell-free system. Fucoxanthin also inhibited comet tail formation and phospho-histone H2A.X expression, suggesting that it prevents hydrogen peroxide-induced cellular DNA damage. Furthermore, the compound reduced the number of apoptotic bodies stained with Hoechst 33342, indicating that it protected keratinocytes against hydrogen peroxide-induced apoptotic cell death. Finally, fucoxanthin prevented the loss of mitochondrial membrane potential. These protective actions were accompanied by the down-regulation of apoptosis-promoting mediators (i.e., B-cell lymphoma-2-associated ${\times}$ protein, caspase-9, and caspase-3) and the up-regulation of an apoptosis inhibitor (B-cell lymphoma-2). Taken together, the results of this study suggest that fucoxanthin defends keratinocytes against oxidative damage by scavenging ROS and inhibiting apoptosis.

Cerebral ischemia exhibits a multiplicity of pathophysiological mechanisms. During ischemic stroke, the reactive oxygen species (ROS) concentration rises to a peak during reperfusion, possibly underlying neuronal death. Recombinant human erythropoietin (EPO) supplementation is one method of treating neurodegenerative disease by reducing the generation of ROS. We investigated the therapeutic effect of PEGylated EPO (P-EPO) on ischemic stroke. Mice were administered P-EPO (5,000 U/kg) via intravenous injection, and middle cerebral artery occlusion (MCAO) followed by reperfusion was performed to induce in vivo ischemic stroke. P-EPO ameliorated MCAO-induced neurological deficit and reduced behavioral disorder and the infarct area. Moreover, lipid peroxidation, expression of inflammatory proteins (cyclooxygenase-2 and inducible nitric oxide synthase), and cytokine levels in blood were reduced by the P-EPO treatment. In addition, higher activation of nuclear factor kappa B (NF-κB) was found in the brain after MCAO, but NF-κB activation was reduced in the P-EPO-injected group. Treatment with the NF-κB inhibitor PS-1145 (5 mg/kg) abolished the P-EPO-induced reduction of infarct volume, neuronal death, neuroinflammation, and oxidative stress. Moreover, P-EPO was more effective than EPO (5,000 U/kg) and similar to a tissue plasminogen activator (10 mg/kg). An in vitro study revealed that P-EPO (25, 50, and 100 U/mL) treatment protected against rotenone (100 nM)-induced neuronal loss, neuroinflammation, oxidative stress, and NF-κB activity. These results indicate that the administration of P-EPO exerted neuroprotective effects on cerebral ischemia damage through anti-oxidant and anti-inflammatory properties by inhibiting NF-κB activation.

Mangiferin is a kind of natural xanthone glycosides and is known to have various pharmacological activities. However, since the beneficial efficacy of this compound has not been reported in retinal pigment epithelial (RPE) cells, this study aimed to evaluate whether mangiferin could protect human RPE ARPE-19 cells from oxidative injury mimicked by hydrogen peroxide (H₂O₂). The results showed that mangiferin attenuated H₂O₂-induced cell viability reduction and DNA damage, while inhibiting reactive oxygen species (ROS) production and preserving diminished glutathione (GSH). Mangiferin also antagonized H₂O₂-induced inhibition of the expression and activity of antioxidant enzymes such as manganese superoxide dismutase and GSH peroxidase, which was associated with inhibition of mitochondrial ROS production. In addition, mangiferin protected ARPE-19 cells from H₂O₂-induced apoptosis by increasing the Bcl-2/Bax ratio, decreasing caspase-3 activation, and blocking poly(ADP-ribose) polymerase cleavage. Moreover, mangiferin suppressed the release of cytochrome c into the cytosol, which was achieved by interfering with mitochondrial membrane disruption. Furthermore, mangiferin increased the expression and activity of heme oxygenase-1 (HO-1) and nuclear factor-erythroid-2 related factor 2 (Nrf2). However, the inhibition of ROS production, cytoprotective and anti-apoptotic effects of mangiferin were significantly attenuated by the HO-1 inhibitor, indicating that mangiferin promoted Nrf2-mediated HO-1 activity to prevent ARPE-19 cells from oxidative injury. The results of this study suggest that mangiferin, as an Nrf2 activator, has potent ROS scavenging activity and may have the potential to protect oxidative stress-mediated ocular diseases.

이동형 위성단말의 운용 환경에서는 장애물로 수신 성능이 감소한다. 하나의 방법으로 Diversity를 적용하여 수신 성능을 향상시킬수 있다. 본 논문에서는 Diversity방법 중 Equal Gain Combining(EGC)방식과 Selective Combining(SC)방식을 적용하여 성능을 분석한다. 분석을 위해 이동형 위성단말로 측정한 결과를 활용한다. 분석결과 SC방식을 사용 시 성능향상을 확인할 수 있었다. 하지만EGC방식은 rural지역에선 성능향상을 보이지만, urban지역에서는 성능이 나빠지는 결과를 확인할 수 있었다.

Reception performance in land mobile satellite is decreased by obstacle. It is compensated with Diversity technique. In this paper, performances are analyzed with two type of method Equal Gain Combining(EGC) and Selcetive Combining(SC). To analyze, measured data using On-The-Move(OTM) terminal are used. In conclusion, SC method can increase performance. However, EGC method can improve perforamance only in rural region, but performance are decreased in urban region.

본 연구는 카이로프랙틱 기법 중 누운 자세에서 시술되어지는 S.O.T category Ⅱ 골반 블록 중재가 골반의 불안정으로 인한 기울어짐을 회복시킴으로써 이에 따른 어깨통증을 줄이고 복근의 지구력을 향상시킬 수 있는지 알아보고자 한 것이다. 이 실험을 위해 엉치엉덩관절의 불안정을 가지고 있으며 허리의 통증이 있는 총 50명의 참여자가 실험군과 대조군에 각 25명씩 무작위 할당되었다. 실험군은 category Ⅱ 블록 중재를 받았고, 대조군은 거짓블록 중재를 받았으며, 이들 두 집단을 통해 중재 전, 중재 후, 그리고 중재 2주 후에 복근지구력과 어깨통증을 측정하여 그 결과를 반복측정 이원분산분석법으로 분석하였다. 분석결과 S.O.T category Ⅱ 골반 블록 중재 후 실험집단에서 복근지구력이 유의한 증가를 보였으며 중재가 끝난 2주 후에도 유지 되었다. 또한 어깨통증의 경우에도 실험집단에서 통증의 감소를 보였으며 역시 중재가 끝난 2주 후에도 유의한 감소를 보였다. 이상의 연구 결과를 종합해 볼 때 S.O.T category Ⅱ 골반 블록 중재는 골반의 안정성을 유도하여 복근지구력을 증진시키고, 어깨통증을 감소시키며 중재 후에도 지속효과가 있는 것으로 나타남으로, 골반의 불안정성이 원인이 되는 어깨통증이나 복근지구력을 회복시킬 수 있는 중재법으로 활용되어질 수 있을 것으로 사료된다.

Objectives: The purpose of this study was to determine whether the sacrooccipital category II blocking technique may improve abdominal muscle endurance and alleviate shoulder pain caused by pelvic tilting. Methods: A total of 50 subjects diagnosed with category II sacroiliac joint instability and lower back pain were randomly assigned to the control or treatment group. The sacrooccipital technique category II blocking procedure (2-min duration) was performed 3 times a week until the category II indicator of joint instability had subsided. The control subjects were subjected to a sham procedure of equal duration and frequency. We assessed abdominal muscle endurance using the partial curl-up test and shoulder pain using a visual analogue scale, before and immediately after the intervention and 2 weeks after the intervention. Results: On two-way analysis of variance with repeated measures on time factor, significant treatment and interaction effects on muscle endurance were found. A significant interaction effect, but not treatment effect, was found for shoulder pain. Post hoc test showed that the shoulder pain was reduced immediately after intervention (treated group) and 2weeks (control and treated group) after the intervention as compared to before the intervention. Conclusions: This study suggests that sacrooccipital category II blocking can be used to alleviate shoulder pain caused by pelvic instability. The mechanisms behind the long-term benefits may include an increase in abdominal muscle endurance.

Background/Objectives: The wireless internet service, which has positioned as an important element to support all industries, can be connected to notebook computers and smartphones everywhere. Using wireless internet access increases, the risk of hacking also increases. Methods/Statistical analysis: There is information leakage accident by modulating DNS address of home router and hacking threats by using wireless router always exists Findings: In this paper, we search hacking techniques using vulnerabilities in wireless LAN, and analyze the need for security for wireless LANs through WEP encryption algorithms and improved encryption algorithms. Improvements/Applications: We also suggest countermeasures against hacking techniques such as DoS attacks, WEP Crack, and DNS Spoofing.